What do smallpox, polio, and measles1 all have in common? They have all been successfully eliminated in the U.S. via wide-spread vaccination. After ten long months, the COVID-19 vaccine roll-out is finally happening and we are well on our way to successfully combating another infectious disease.

What will determine if the new vaccines are successful?

Simply put, people need to get vaccinated for a vaccine to be effective. Yes, the vaccine itself must be safe and have high efficacy (i.e., create an adequate immune response in those vaccinated), but ultimately what determines if a vaccine is truly successful at eliminating a disease in a population comes down to herd immunity.

What is herd immunity?

Herd immunity is the act of protection that is provided when enough of a population gains immunity to an illness that it halts transmission. Every infectious disease has a reproduction number or R0 (pronounced “R naught”). This calculation is the average number of people an infected individual will infect in an at-risk (non-immune) population. Inevitably, for any given disease, the R0 calculations can vary widely, but are generally based on three primary characteristics:

  1. How long an individual is contagious while infected
  2. The likelihood of infection per contact between an infectious person and a susceptible person
  3. How often people are encountering one another (contact rate)

With COVID-19, R0 estimates change based on location and population, but some studies calculate it being as high as 5.7 (95% CI 3.8–8.9) .2 So, if I am infected with COVID-19 and interacting with a completely vulnerable group of individuals, on average, I could expect to infect five other people. To reach herd immunity, you essentially need to pass an immunity threshold that makes it so that an infected person has no one to transmit the infectious disease to because no one around them is susceptible (R0 < 1).3

Herd Immunity Blog Post

Why do we need to get vaccinated?

Herd immunity has been a hot topic throughout the pandemic as there are only two ways to truly achieve it: 1) natural immunity via infection and 2) immunity via vaccination. Unfortunately, when it comes to most infectious diseases, natural immunity through active infection might not be enough to offer full protection and any immunity provided could dissipate over time leaving some individuals vulnerable to reinfection. Additionally, waiting for a population to become infected, and therefore immune, can take a very long time and may result in unnecessary deaths and long-term health implications.

One great example of this is chickenpox. Not long ago, parents would purposely expose their children to infectious individuals to ensure immunity was developed at a young age. I can remember vividly being forced on a play date while covered in spots. Unfortunately, to achieve this natural herd immunity, each year, over 10,000 were hospitalized and an estimated 100-150 died. After the vaccine became widely available in the U.S. in 1995, more than 3.5 million cases of chickenpox are now prevented each year.4

How many people need to get vaccinated to achieve herd immunity?

The estimated number of people that need to get vaccinated to achieve herd immunity depends on several factors:

  1. The infectious disease and how contagious it is.
  2. The proportion of people that are susceptible in a population.
  3. The overall effectiveness of the vaccine.

Experts do not yet know what that threshold is for COVID-19. This is because we do not know how many of us already have immunity. Dr. Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases, estimates that around 75% of the public needs to get vaccinated for herd immunity to provide protection and truly stop the spread of COVID-19.5

How do we learn more about the COVID-19 vaccines and the plan to reach herd immunity?

Concerns over the speed with which these vaccines were developed are warranted. We should all do our due diligence with any new public health intervention. Thankfully, the information on safety is widely available. Here are three comprehensive resources to help address any concerns you, your family, or your staff may have:

What can we do now?

The Centers for Disease Control and Prevention (CDC), in consultation with the U.S. Advisory Committee on Immunization Practices (ACIP), is prioritizing vaccine distribution in a fair and ethical way and continuing to provide transparent updates on the vaccine roll-out plan. While we wait for our turn to be vaccinated, we need to remind our family, friends, and staff to continue to do all the things that we have been doing – wear masks, maintain social distance, avoid indoor and poorly ventilated spaces, wash our hands, and clean and disinfect regularly. We do these things to protect ourselves, but more importantly, to protect others. That is also true of vaccines. We get them to create herd immunity and protect those in our society that are most vulnerable. I, for one, am looking forward to adding another eliminated disease to the above vaccine success list – smallpox, polio, measles, and COVID-19!


  1. Measles Elimination [Internet]. Centers for Disease Control and Prevention (CDC). 2020. [cited 2020 Dec 8] Available from: https://www.cdc.gov/measles/elimination.html
  2. Sanche S, Lin YT, Xu C, Romero-Severson E, Hengartner N, Ke R. High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2. Emerg Infect Dis [Internet]. 2020. [cited 2020 Dec 8] Available from: https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article
  3. Delamater PL, Street EJ, Leslie TF, Yang YT, Jacobsen KH. Complexity of the basic reproduction number (R0). Emerg Infect Dis [Internet]. 2019. [cited 2020 Dec 8] Available from: https://wwwnc.cdc.gov/eid/article/25/1/17-1901_article
  4. Chickenpox (Varicella) [Internet]. Centers for Disease Control and Prevention (CDC). 2020. [cited 2020 Dec 8] Available from: https://www.cdc.gov/chickenpox/about/index.html
  5. Armour, S. Fauci Calls Coronavirus Vaccine a Game Changer, Decries Misinformation [Internet]. The Wall Street Journal. 2020 Dec 8. [cited 2020 Dec 8] Available from: https://www.wsj.com/articles/deborah-birx-and-anthony-fauci-to-discuss-coronavirus-response-11607432098

Within the past three months, there have been more and more articles written about “Sanitization or Hygiene Theater.”1 The concept is based off “Security Theater,” a term which was used post-9/11 to describe the increased TSA measures that, arguably, did little to prevent future attacks.2 The comparison is founded on the notion that all the pandemic-induced cleaning, sanitizing, and disinfecting may be completely unwarranted and even wasteful in terms of time and money. In August 2020, Dr. Emanuel Goldman, a Professor of Microbiology at Rutgers University published a commentary based on comprehensive scientific literature review in The Lancet stating that “the chance of [SARS-CoV-2] transmission through inanimate surfaces is very small, and only in instances where an infected person coughs or sneezes on the surface, and someone else touches that surface soon after the cough or sneeze (within 1–2 h) [is there a risk].” Dr. Goldman goes on to say that “although periodically disinfecting surfaces and use of gloves are reasonable precautions especially in hospitals, I believe that fomites that have not been in contact with an infected carrier for many hours do not pose a measurable risk of transmission in non-hospital settings.”3

As a Public Health Professional, I cannot help but pause to contemplate this perspective. On one hand, the CDC confirms that “COVID-19 is thought to spread mainly through close contact from person-to-person, including between people who are physically near each other (within about 6 feet).” Though guidance still encourages “routinely clean[ing] and disinfect[ing] frequently touched surfaces.”4 On the other hand, I have been advocating for better disinfection practices in both healthcare and private settings for my entire career. I see this new world mindset as an incredible public health achievement. Infection Prevention is no longer a term isolated to the four walls of the hospital — we, now more than ever, are all more aware of the need for disinfection within our businesses as employees (or owners), as consumers, and even in our own homes. If you were to travel back to pre-pandemic times (possible via a quick Google search), illnesses such as the flu, common colds, and stomach bugs (gastroenteritis) were already a substantial burden in terms of absenteeism, diminished productivity, and increased healthcare costs.5 Influenza infections in adults alone resulted in an estimated $87 billion per year in terms of healthcare costs, projected lost earnings, and loss of life.6

Even knowing all of this, prior to the pandemic, employees and customers accepted a certain level of risk when it came to the safety of our shared public spaces. Post-pandemic, that accepted trust in the world around us is gone. Deloitte recently published a Safety and Cleanliness Survey7 which demonstrated that in addition to wearing masks and providing hand sanitizer, the top interventions businesses can take to rebuild trust are:

For Customers:

For Employees:

Source: Deloitte Safety & Cleanliness Survey, Deloitte Consulting LLP, 2020

Not only are these practices what we should have been doing all along, it is evident that the public is now looking for consistent displays of safety and cleanliness to trust businesses moving forward. However, as highlighted in the recent CloroxPro blog, Smart Disinfection: Making the Most of Your Disinfectants, it is important to develop a plan for using disinfectants efficiently and effectively. There is undoubtedly a balance that businesses need to find, and “hygiene theater” cannot be the only public health protocol put into practice. Any cleaning and disinfection efforts need to be used in combination with other CDC recommended initiatives, including social distancing, mask wearing, handwashing, staying home when sick, and improving indoor ventilation.4 The idea of Dr. James Reason’s 1990 “Swiss Cheese Model” still holds true today. The safeguards recommended represent the multiple layers needed to protect consumers and employees, alike. As pointed out by the Cleveland Clinic, “when used together consistently, the holes (or weaknesses) in any single layer of protection should be offset by the strengths of another layer of intervention.”8 We have to address every area of potential spread to truly create a safe and healthy environment for all.


  1. 1. Thompson D. Hygiene Theater Is a Huge Waste of Time: People are power scrubbing their way to a false sense of security. [Internet]. The Atlantic. 2020 [cited 2020 Oct 6]. p. 1–8. Available from: https://www.theatlantic.com/ideas/archive/2020/07/scourge-hygiene-theater/614599/
  2. 2. Judkis M. Deep cleans and disinfecting mists might not keep us from getting the virus , but they sure make us feel better [Internet]. The Washington Post. 2020 [cited 2020 Oct 6]. Available from: https://www.washingtonpost.com/lifestyle/style/deep-cleans-and-disinfecting-mists-might-not-keep-us-from-getting-the-virus-but-they-sure-make-us-feel-better/2020/09/05/f428b8ee-e965-11ea-97e0-94d2e46e759b_story.html
  3. 3. Goldman E. Exaggerated risk of transmission of COVID-19 by fomites [Internet]. Vol. 20, The Lancet Infectious Diseases. 2020. p. 892–3. Available from: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30561-2/fulltext
  4. How COVID-19 Spreads [Internet]. Centers for Disease Control and Prevention (CDC). 2020 [cited 2020 Oct 6]. Available from: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html
  5. 4. Bramley TJ, Lerner D, Sames M. Productivity losses related to the common cold. J Occup Environ Med. 2002.
  6. 5. Keech M, Beardsworth P. The impact of influenza on working days lost: A review of the literature. PharmacoEconomics. 2008.
  7. 6. Safety and cleanliness – make it or break it. [Internet]. Deloitte Consulting, LLP. 2020 [cited 2020 Oct 6]. p. 1–5. Available from: https://www.deloittedigital.com/content/dam/deloittedigital/us/documents/offerings/offering-20200626-safety-cleanliness-covid.pdf
  8. 7. Return to Work Amid COVID-19 [Internet]. Cleveland Clinic. 2020 [cited 2020 Oct 9]. p. 5. Available from: https://my.clevelandclinic.org/-/scassets/files/org/employer-solutions/covid-19-returning-to-work-guide.ashx

This post is part of our "Ask The Pros" blog series for which our internal panel of experts address the latest questions from industry professionals. This month's query,

"It seems like we have a new disinfectant product every week and it's hard to keep up with how and where to use the products. What strategies do you recommend for as little disruption as possible to our current process?"


The year 2020 has certainly been a challenging one thus far. The COVID-19 pandemic has created supply challenges in this country that we could not have anticipated that range from U.S. Mint coin shortages to personal protective equipment (PPE) for healthcare workers.  The disinfectant manufacturing industry has also been challenged to keep up with an extraordinary increase in demand.  While production facilities are operating 24/7, supply continues to fall short of demand due to production capacity and raw material shortages.  As a result, many healthcare facilities are having to adjust and adapt to new disinfectants products, whether that means different formats, applications, or actives.  While this may be frustrating, healthcare teams are resilient and they know how to triage.  In response to disinfectant shortages, changes in product and potentially in protocols, we will apply the methodology of triage to the use of disinfectant products in formats that may differ from our usual product. A plan of action can then be developed for the appropriate use of the environmental disinfectants available.

Risk Assessment

The first step when an issue is identified is to assess the risks involved and the potential consequences.  In this case, the issue is that our usual product(s) may be temporarily unavailable, or in limited supply. I recommend downloading and adapting a risk assessment tool from the Centers for Disease Prevention and Control (CDC). Considerations with the risk assessment are:

Once the risk assessment has been completed, the next step is to formulate a plan to mitigate and determine what, if any, safeguards should be put into place.  Your plan should include goals and objectives to tackle high-risk issues. Note that your plan should also address how you will swiftly communicate the change in product and educate staff as the new products come in to your facility. Your vendors may be able to help!

Product Prioritization

Much like the CDC has recommended a strategy to prioritize the use of PPE to preserve supply, consider doing something similar in regards to disinfectants.  I am not proposing cleaning less frequently, but rather to prioritize which products will be used where and by whom.  If you have a limited supply of disinfectant wipes, but you also have some spray bottles of disinfectant, consider prioritizing disinfectant wipes for critical departments, or equipment.  For example, you wouldn’t want to use the spray disinfectant in the ICU where you have patients on a ventilator, so this would be a department in critical need of disinfectant wipes. Another example might be to take the large format disinfectant wipes that Environmental Services (EVS) often use and distribute them to nursing staff for use on the units.  EVS is more accustomed and likely more equipped to utilize different formats of disinfectants such as spray disinfectants, dilutable chemistries and microfibers so consider reserving these formats for them.

If you need help getting started with how to prioritize your products, check out this flow chart (also pictured below) and associated blank and completed risk assessments for reference.

Instructions for Use

Through all of this, it is imperative that the product instructions for use (IFU’s) are reviewed, staff is educated on the IFU’s, and compliance is monitored and enforced by leadership. Healthcare-grade disinfectants registered by the U.S. Environmental Protection Agency (EPA) undergo stringent testing requirements in order to prove their efficacy and safety. For the best results, users should follow the product IFU’s.

For example, Clorox Healthcare® Fuzion, a next-generation sporicidal bleach disinfectant, has an engineered dual-chambered nozzle that combines the active ingredients at the point of dispensing (or spraying).  While highly efficacious, this product is most effective when applied directly to the surface from the bottle itself. If concerned about using sprays but that is all that is available, a better approach would be to consider where use of sprays might be more appropriate, such as in public or common areas after-hours. Finally, until this pandemic is behind us, be sure you are selecting products approved as being effective against SARS-CoV-2, the virus responsible for COVID-19 disease.  You can find these products on the EPA’s List N.

Posts for the Ask The Pros blog series are published every other month. Please submit your cleaning and disinfecting questions to AskThePros@clorox.com for consideration to be addressed in a future edition.

This is the final post of a three-part blog series, COVID-19: Transition from Hospital to Home, by Doe Kley. Read part one and part two.

In part one of this 3-part blog series, we learned about SARS-CoV-2, the virus responsible for COVID-19 infection. We reviewed how infections occur using the Chain of Infection framework, including ways in which the chain can be broken to stop transmission. A special emphasis was placed on the role of environmental surfaces in transmission. In part two, we focused on preventing the transmission of COVID-19 within the hospital, looking at both what hospitals are doing and what patients can do. Next, we shared ways to prevent transmission to household contacts within the home environment. In this final part, we will review disinfectant safety and understanding the label.

Disinfectant Safety

The COVID-19 pandemic has brought to light the need for safe use of cleaners and disinfectants. Calls to Poison Control Centers regarding exposures to cleaners and disinfectants have increased since the beginning of 2020. In fact, the CDC published a Morbidity and Mortality Weekly Report (or MMWR) on this very topic in June of this year. They conducted a survey and found knowledge gaps in the safe use of household cleaners and disinfectants. Approximately one-third of the respondents reported engaging in non-recommended high-risk practices with the intent to prevent the spread of COVID-19 virus. Some of these unsafe practices include washing produce with bleach, applying these household cleaner-disinfectants to bare skin, and intentionally inhaling or ingesting these products.

It’s important to be knowledgeable about cleaning and disinfectant products being used. The product label provides a wealth of information so be sure to read it. A very important piece of information to look for is the registration number from the Environmental Protection Agency (EPA). All disinfectants in the US are required to be registered with the EPA. Failure of a disinfectant product to be registered with the EPA is not only against federal law, without it, the safety and efficacy of unregistered products cannot be guaranteed. 

Other important information that can be found on the product label are the chemicals or active ingredients, the germs they kill ("kill claims"), precautions, and directions for use (DFUs). Keep in mind that SARS-CoV-2 is a new pathogen so it may not yet be listed on the label. However, if the product has the emerging viral pathogen claim and is listed on EPA’s List N, then the product is approved for use against the COVID-19 virus.

The precautionary text informs the user of potential hazards when using (or misusing the product). Signal words used in the precautionary text include CAUTION, WARNING, or DANGER and informs the user of physical or chemical hazards such as flammability and corrosiveness. This label section also advises on first aid instructions and if the product should be kept out of reach of children.

The DFUs focus on what task (e.g., disinfect, sanitize, deodorize, etc) the product is intended to perform and how to correctly use the product. This includes surfaces that the product can safely be used on as well as those the product should not be used on. The DFUs provide the contact time or how long the surface must remain wet with the disinfectant in order to be fully efficacious. It also addresses whether it’s safe or not to mix the product with other products or chemicals. For example, toxic fumes can result when bleach is mixed with ammonia or vinegar. Adherence to the DFUs is key.  If product DFUs state to apply the product directly to the surface followed by wiping once the contact time has been met, then applying the product to the cloth first may impede efficacy.

Some key safety measures to consider include:


In this 3-part blog series, we addressed the safe transition from hospital to home during a pandemic as it can be a very scary experience. And we learned that with basic infection control measures we can protect both ourselves and our loved ones. The COVID-19 pandemic has shown a glaring light on the need to faithfully adhere to these basic practices. Frequent hand hygiene, respiratory etiquette, and routine cleaning and disinfection go a long way in preventing transmission of pathogens, including SARS-CoV-2, the cause of COVID-19.

Be sure to educate yourself on proper cleaning and disinfection and understand what is in the bottle and how to safely use it. Always follow the instructions for use. Be sure you allow surfaces to remain wet long enough to kill the targeted pathogens.  This means adhering to the contact time on the label for the product you are using.  

To learn more, visit the CloroxPro Resource Center which includes valuable educational resources such as videos, pathogen education sheets, CE webinars and more.


1. Coronaviruses. Retrieved from https://www.niaid.nih.gov/diseases-conditions/coronaviruses

2. Coronavirus Disease 2019: Frequently Asked Questions. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/faq.html

3. Disease 2019: How it Spreads. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html.

4. New coronavirus stable for hours on surfaces. Retrieved from https://www.nih.gov/news-events/news-releases/new-coronavirus-stable-hours-surfaces.

5. COVID-19, FAQ, Spread. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/faq.html#:~:text=At%20this%20time%2C%20CDC%20has,Coronavirus%20Spreads%20for%20more%20information.

6. Coronavirus Disease 2019: Symptoms. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html

7. Are You at Higher Risk for Severe Illness? Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/specific-groups/high-risk-complications.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fhigh-risk%2Fhigh-risk-complications.html

8. Severe Outcomes Among Patients with COVID-19 – United States, February 12-March 16, 2020. Retrieved from https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e2.htm

9. COVID-19 Cases in U.S. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/cases-in-us.html

10. CDC Media Telebriefing: Update on COVID-19, March 9, 2020. Retrieved from https://www.cdc.gov/media/index.htmlhttps://emergency.cdc.gov/coca/calls/2020/callinfo_013120.asp

This is the second post of a three-part blog series, COVID-19: Transition from Hospital to Home, by Doe Kley. Read part one and part three.

In part one of this blog series, we described COVID-19 disease and used the chain of infection to demonstrate how this and other infections occur. In part two of this series, we will address how the spread of COVID-19 can be prevented within the hospital, as well as how to prevent its spread to loved ones within the home.

Preventing Transmission in the Hospital

Measures the healthcare team is taking to prevent transmission of COVID-19 to patients and others within the hospital walls include:

For additional recommendations, see CDC’s Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic.

For disinfectants effective against the SARS-CoV-2 virus, see the Environmental Protection Agency’s (EPA) List N. This list includes disinfectants used in healthcare settings as well as disinfectants used at home. It’s important to note that while SARS-CoV-2 can cause severe illness in some, the virus is very easy to kill on surfaces with appropriate disinfection.

Hierarchy of Pathogen Kill

Adapted from Rutala, WA and Weber, DJ retrieved on 8/30/2020 from www.epa.gov

For patients admitted for a health issue other than COVID-19, there are things that they can do to protect themselves from getting COVID-19 while in the hospital. First and foremost, patients must be their own advocate.  This means speaking up when something doesn’t look or seem quite right.   This includes reminding healthcare workers and visitors to perform hand hygiene before touching you. Along these same lines, patients should be sure to perform hand hygiene before they eat or before taking oral medications, after they use the restroom, and upon returning to their room from a test or procedure or even a walk in the halls. It’s also important to ensure your room and bathroom are cleaned every day you are in the hospital. Focal points for cleaning should include surfaces that are frequently touched such as the over-bed table, bed rails, call light, and tv remote to name a few. Additionally, patients should ensure that the healthcare team has disinfected any medical equipment that will come into contact with them. Lastly, during the pandemic, patients should wear a mask as tolerated while in the hospital to help prevent inadvertent exposure to COVID-19.

Similarly, there are things that essential workers can do to prevent bringing COVID-19 home from work with them and infecting their family members. The COVID-19 pandemic has certainly made us take a closer look at how we can safely transition from work to home each day to protect not only ourselves but our loved ones.  Please see my blog post from March 2020 titled “From Outside In: 6 Tips for Minimizing the Risk of Bringing COVID-19 Home After Your Shift”.  

Preventing Transmission in the Home

There are measures that patients infected with COVID-19 can do to prevent infecting their loved ones when it’s time to be discharged from the hospital.  Adherence to the 6 basic measures that we all should be doing will go a long way in preventing the spread of COVID-19:

  1. Stay home if feeling unwell
  2. Practice social distancing
  3. Wear a mask and cover coughs/sneezes
  4. Avoid touching the face
  5. Perform frequent hand hygiene
  6. Perform frequent cleaning and disinfection of environmental surfaces

To clean surfaces in the home that may be contaminated with the SARS-CoV-2 virus be sure to use an EPA-registered household disinfectant.  Most of these will be effective as this is not a difficult virus to kill (see Hierarchy of Kill image above). For a complete list of appropriate household disinfectants for COVID-19, visit the Clorox Coronavirus Resource page to view a list of approved products and tips on how to safely and effectively disinfect surfaces in the home. Additionally, diluted jug bleach can be used to disinfect surfaces.

1:10 Jug Bleach Dilution

In addition to frequent cleaning and disinfection of frequently touched surfaces in the home, only one person in the household should take care of the person who is ill.  And this person should not be someone in the high-risk group for COVID-related complications. In addition to the 6 basic measures mentioned earlier, the ill person should:

Everyone in the household, especially the ill person, should practice respiratory etiquette which includes covering coughs and sneezes, properly discarding used tissues, and performing frequent hand hygiene. Also, avoid sharing personal items with others in the home including dishes, towels, and bedding.

The COVID-19 infected person should remain separated from others in the household, including pets, by staying in a designated room. This person should also have a separate bathroom, if possible. If the bathroom must be shared, then after each use, the frequently touched surfaces should be cleaned and disinfected.

The bathroom and the “sick room” are not the only rooms in the house that should be cleaned frequently. All frequently-touched surfaces in the home should be cleaned and disinfected daily at a minimum according to the Centers for Diseases Control & Prevention (CDC), but it certainly doesn’t hurt to disinfect more frequently.

If sleeping in the same room is necessary, put a curtain up to act as a divider. And if you must share a bed, sleep head-to-toe. Weather permitting, open doors and windows and use fans to help circulate fresh air. The ill person should not prepare food and should eat separately from the rest of the family.

Read part 3 of the blog series as we end with the safe and proper use of disinfectants.

This is the first post of a three-part blog series, COVID-19: Transition from Hospital to Home, by Doe Kley. Read part two and part three.

Transitioning from hospital to home once diagnosed with an infectious disease can be frightening for a patient. The biggest concern is spreading the infection to their loved ones. This blog post focuses on SARS-CoV-2, the virus responsible for COVID-19.  In addition to providing some information on this pathogen and the infection that it causes, key things to consider when it’s time to go home for preventing transmission to others will be addressed. 

About COVID-19

According to the National Institute for Allergy and Infectious Diseases (NIH), over the past 20 years, three new pathogenic Coronaviruses have emerged from animal reservoirs.1 They are a large family of viruses that commonly cause respiratory illnesses in people as well as in many different animal species.2 Examples include Severe Acute Respiratory Distress Syndrome (SARS) back in 2003 and more recently, Middle Eastern Respiratory Syndrome (MERS).2 The COVID-19 strain, genetically related to the SARS virus, has not been identified in humans until now.3 Our lack of immunity to this virus explains its readiness to spread from person-to-person. 

And how is this virus spread? Well, the primary mode is through respiratory droplets when an infected person coughs or sneezes.4 These droplets have about a 6 foot reach.4 While there is some evidence that persons without any symptoms can transmit the virus, persons are most infectious when they are actively ill.4 Additionally, it appears to be possible to acquire COVID-19 by touching surfaces or objects contaminated with the virus and then touching your mouth, nose, or eyes5, but this is not thought to be the main way that this virus is spread.4 Studies are being published at lightning speed and indicate that the virus can survive from several hours to several days on various surfaces.6 Finally, it’s important to point out that this virus is not spread through food or water. 

Symptoms of COVID-19 illness are very similar to influenza and include fever, cough, muscle aches, fatigue, and shortness of breath.6 However, the incubation period is longer than influenza ranging from 2-14 days (average of 4-5 days).6,7 Influenza and COVID-19 illnesses both come on more suddenly as compared to the common cold which tends to come on more gradually. Like influenza, COVID-19 illness can range from mild to severe.8

Coronavirus Sympton Comparison with Other respiratory Illnesses

The vast majority of persons (80%) with COVID-19 infection will experience only mild illness and will recover uneventfully.9 Persons at high-risk of complications from this disease tend to have more severe illness.10 These high-risk individuals include those over the age of 60 years and those with chronic conditions such as heart or lung disease and diabetes.10  Of the older population, those over the age 80 years are at highest risk of complications from COVID-19.10  Currently, there is no specific treatment to cure COVID-19 and there is no vaccine but experts are currently working on both. The mortality rate in the US is approximately 1.3%.10 This means we can expect approximately 1.3 persons in every 100 cases to die as a result of the infection. While this does not seem like a high mortality rate, keep in mind that this is an average. The mortality rate is significantly higher in high risk individuals and lower in low risk individuals.

The Chain of Infection

A framework that can help us to understand how infections occur is the “chain of infection” which describes the sequence of events that must occur in order for an infection to occur. This chain applies to all pathogens. When considering this framework, envision the links of a chain connected in a continuous circle in which the cycle repeats itself unless or until broken. 

The chain of infection is made up of six links. Each link must align in order for an infection to occur, starting with an infectious agent such as SARS-CoV-2, the virus responsible for COVID-19. The second link is the reservoir for the infectious agent. Reservoirs can include people, environmental surfaces, water, air, and so on. And there must be a portal of exit (which is the third link) for the pathogen from its reservoir. An example of a portal of exit would be the respiratory tract of a coughing patient infected with COVID-19. The fourth link is the mode of transmission. This is how the infectious agent or pathogen is carried from one place or person to another.  For example, COVID-19 is spread in the droplets of saliva or mucous coughed out from an infected person. And if those droplets land on and contaminate an environmental surface, the virus can potentially be transmitted by touching that surface and then rubbing one’s eyes or nose. The fifth link in the chain is the portal of entry. This is how the pathogen enters its host or a susceptible person. The portal of entry for the COVID-19 virus is when a susceptible person breathes in the virus carried in droplets from an infected person coughs, sneezes, sings, or talks. The final link is a susceptible host. This is a person who is not immune to or is otherwise susceptible to the infectious agent they are exposed to. In essence, since COVID-19 is caused by a new strain of Coronavirus, we all are susceptible hosts to some degree.

The good news is that we can stop infections from occurring by breaking just one link in the chain. This can easily be accomplished through actions such as covering coughs, performing frequent hand hygiene, cleaning and disinfecting environmental surfaces routinely, and keeping current on immunizations. For COVID-19, we can break the chain of infection for (and possibly put the brakes on this pandemic) by doing these things plus practicing social distancing – keep at least six feet from others and wear a mask. Remember, my mask captures my droplets which protects you and your mask captures your droplets which protects me.

Read part two of this blog series where we discuss preventing the spread of COVID-19 in the hospital, as well as at home.


  1. Coronaviruses. Retrieved from https://www.niaid.nih.gov/diseases-conditions/coronaviruses
  2. Coronavirus Disease 2019: Frequently Asked Questions. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/faq.html
  3. Disease 2019: How it Spreads. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html.
  4. New coronavirus stable for hours on surfaces. Retrieved from https://www.nih.gov/news-events/news-releases/new-coronavirus-stable-hours-surfaces.
  5. COVID-19, FAQ, Spread. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/faq.html#:~:text=At%20this%20time%2C%20CDC%20has,Coronavirus%20Spreads%20for%20more%20information.
  6. Coronavirus Disease 2019: Symptoms. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html
  7. Are You at Higher Risk for Severe Illness? Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/specific-groups/high-risk-complications.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fhigh-risk%2Fhigh-risk-complications.html
  8. Severe Outcomes Among Patients with COVID-19 – United States, February 12-March 16, 2020. Retrieved from https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e2.htm
  9. COVID-19 Cases in U.S. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/cases-in-us.html
  10. CDC Media Telebriefing: Update on COVID-19, March 9, 2020. Retrieved from https://www.cdc.gov/media/index.htmlhttps://emergency.cdc.gov/coca/calls/2020/callinfo_013120.asp

Have you been asked to take on the role of part time cleaner in your facility or business? If so, welcome to the club!

With the COVID-19 virus still widespread across the U.S., employers everywhere, from schools, offices, athletic facilities, movie theaters, hotels, restaurants, hospitals, and more, are asking non-cleaning staff to clean.

In a recent back to school survey, more than half (58%) of 120 educators polled responded that they would be asking current staff members/teachers to do some cleaning and disinfecting as part of their regular duties. In other facilities, box office staff, airline gate attendants, check-out clerks, nurses, receptionists and more are being asked to help out with daily cleaning and disinfecting of frequently touched and shared surfaces. The CDC has even stated in the Reopening Guidance for Cleaning and Disinfecting Public Spaces, Workplaces, Businesses, Schools, and Homes, that “This guidance is intended for all Americans.”

Depending on your personality and past experiences, you may have had any one of these three reactions:

  1. What? No way, cleaning isn’t in my job description and I don’t have time for that!
  2. Great, cleaning is easy enough. I just use common sense, right?
  3. OK, but I don’t know how to clean properly. Where do I get training?

The good news is that no matter which group you fall into, the COVID-19 pandemic is offering up an opportunity to learn about something many of us wouldn’t have taken the time to do before. And that is how to clean and disinfect properly.

The truth is, although many don’t realize it, properly cleaning and disinfecting surfaces takes education, training, and even practice to perfect. In fact, there is an entire industry focused on helping to ensure that cleaning professionals get what they need to do their job well. IICRC, ISSA, and AHE are just a few examples of organizations with this goal in mind.

While your employer is ultimately responsible for making sure you are educated and trained, here are some basics to help get you started. You can use this information to talk to your employer about what’s important, and potentially even as a starting place for a “new cleaner” training guide for your facility.

What is the difference between cleaning, sanitizing, and disinfecting?

Does cleaning always need to be done before disinfecting?

No. Cleaning and disinfecting can be done at the same time if these criteria are met:

How can I be sure I’m using a product that kills “xyz” germ?

What else is important to understand about the product, and where can I get the information?

What else do I need to know to clean and disinfect properly?

COVID-19 has presented us with quite a challenge to say the least. Fortunately, there have also been a few “silver linings” along the way. One is the knowledge and skills about cleaning and disinfecting properly that few had before. If you have been asked to take on additional cleaning and disinfecting responsibilities as part of your current role, as in any profession, education and training on how to do the job right are essential. This will not only help ensure goals of the job (e.g., to reduce the spread of germs in the environment) are achieved, but to also ensure that the job is done safely.

With the ongoing pandemic and the flu season around the corner, it’s important to develop a plan for using disinfectants efficiently and effectively. There’s a time and place for cleaning, and a time and place for disinfection, and doing the right amount of each can help safeguard public health. During the pandemic, disinfectant use is on the rise, and there is a growing conversation around overuse of disinfectants.

To address this concern and make the most of the limited products available during the pandemic, it’s important to target disinfection to the surfaces and places where it is needed most. Depending on the type of facility and how people are using that facility, some areas might require cleaning only, while others may need both cleaning and disinfection. Smart disinfection—that is, targeting disinfectants to when and where they are needed most—can help conserve disinfectants and maximize protection for the people who use those spaces.

Cleaning, Sanitizing and Disinfecting

Before deciding on a plan for smart disinfection, it’s important to know the difference between cleaning, sanitizing, and disinfecting. Cleaning is the physical removal of dirt and debris from surfaces. Cleaning products contain a surfactant or detergent to break up dirt and debris, but are not Environmental Protection Agency (EPA) registered. Cleaning products cannot make claims to kill bacteria or viruses on surfaces. Sanitizers and disinfectants contain an antimicrobial active ingredient and are EPA registered. Sanitizers reduce the number of bacteria on surfaces, but cannot make claims against viruses, so they cannot be used to kill for example SARS-CoV-2, the virus that causes COVID-19. Disinfectants can be registered to kill bacteria, fungi and viruses on surfaces, including SARS-CoV-2. Some products are one-step cleaner disinfectants, meaning that they contain both surfactants and an antimicrobial ingredient, so they can clean and disinfect in the same step.

When and Where to Disinfect

Manual disinfectants like wipes and trigger sprays are great tools for regular disinfection of spaces and surfaces that people touch frequently throughout the day. In schools for example, it makes sense to disinfect desks, doorknobs and other high-touch surfaces by wiping or spraying them in between classes, but you may not need to disinfect every surface in every room throughout the day. On the other hand, high traffic areas like restrooms may need to be disinfected top to bottom, multiple times throughout the day. According to the Centers for Disease Control and Prevention (CDC), high-touch surfaces that may require frequent disinfection throughout the day include tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.1,2

Thorough cleaning and disinfection of the entire facility usually happens after hours, after building occupants have gone home. This process could involve cleaning (such as vacuuming and dusting), followed by manual disinfection with wipes, trigger sprays or dilutable disinfectants.

For extra assurance that all surfaces are disinfected, electrostatic spray disinfection can be added to and even replace parts of this routine. For example, you could clean high-touch surfaces in classrooms, and then use an electrostatic sprayer to apply a disinfectant quickly and evenly to all surfaces in the room. This could include soft surfaces or surfaces that are difficult to thoroughly clean, such as chairs and desks. Electrostatic spraying can also be used as a substitute for manual wipes and sprays in areas that are large and hard to disinfect manually, such as restrooms, locker rooms or cafeterias. Keep in mind however that high-touch surfaces should still be the focus when using an electrostatic sprayer in public spaces. For example, although walls and floors can be disinfected, these areas may only require cleaning depending on the facility type and room traffic.

Develop a Smart Disinfection Plan

To develop a smart disinfection plan, first determine which surfaces and areas in your facility need to be disinfected. Once you’ve identified the areas and surfaces in your facility that need to be disinfected, you can develop a plan to decide when those surfaces should be disinfected and by whom. Let staff know who is responsible for each area, and what needs to be done in that area. Checklists are a great tool to help staff and managers keep track of what has been done throughout the day. Staff should also be trained on the safe use of disinfectants. Disinfectants are safe when used as directed, so it’s important to always follow label instructions for use. Appropriate personal protective equipment should also be worn by the operators applying disinfectants.

If you need guidance to help you complete your smart disinfection plan, there are several comprehensive tools and resources available. For example, the CDC has guidance on cleaning and disinfecting public spaces, offices and businesses, schools, and homes that includes a disinfection decision tree.3 For educational facilities, there are multiple resources available on cleaning and disinfection, including information on how to open facilities safely.4,5

For more information, please see the following SARS-CoV-2 resources.


1. Centers for Disease Control and Prevention (CDC). Cleaning and Disinfecting Your Facility https://www.cdc.gov/coronavirus/2019-ncov/community/disinfecting-building-facility.html (accessed Sep 3, 2020).
2. Centers for Disease Control and Prevention (CDC). Cleaning And Disinfecting Your Facility https://www.cdc.gov/coronavirus/2019-ncov/community/disinfecting-building-facility-H.pdf (accessed Aug 28, 2020).
3. Centers for Disease Control and Prevention (CDC). Guidance for Cleaning and Disinfecting https://www.cdc.gov/coronavirus/2019-ncov/community/cleaning-disinfecting-decision-tool.html (accessed Aug 28, 2020).
4. National Education Association; The Clorox Company. Cleaning , Sanitizing , and Targeted Disinfecting in the Classroom.
5. Centers for Disease Control and Prevention. Guidance for Cleaning and Disinfecting https://www.cdc.gov/coronavirus/2019-ncov/community/pdf/Reopening_America_Guidance.pdf.

Also published on The Clorox Company’s Good Growth Blog, the following post offers cleaning and disinfection best practices and various resources available for healthcare and cleaning professionals to help prevent the spread of COVID-19.

In the midst of this pandemic, we’re all performing many actions every day to help slow the spread of SARS-CoV-2, the virus that causes COVID-19. We wear masks and keep at least six feet from others in public. We wash our hands more frequently and regularly clean and disinfect surfaces in our homes and workplaces.

My work life at Clorox, focused on cleaning and disinfection, has started to collide with my life outside work. I have witnessed what I’ve termed the “Disinfection Enlightenment” as people pay closer attention to the cleanliness of their homes and public spaces. In mainstream media and conversations with friends and family, I hear words like “sanitize,” “disinfect,” “EPA List N,” “dilution” and “contact time” that previously belonged to my work world. This mixing of my work and personal life became abundantly clear when my mom, a school teacher, called and asked, “How many desks can I clean with one disinfecting wipe and still be sure I’m killing the virus that causes COVID-19?”

Sure, most people will say that cleaning and disinfection are easy tasks. However, it takes training and practice to safely and effectively complete both.

When I started at Clorox many years ago, I became enlightened to the importance of using disinfectants properly. I “relearned” many of the basics — from the importance of using the proper dilution and freshly preparing bleach solutions when using Clorox® Germicidal Bleach to disinfect my bathroom to creating a cleaning path starting from the cleanest area of a room to the dirtiest area to prevent “cross-contamination” to the way germs spread from one surface to another.

In fact, my team and I spend a lot of time educating healthcare and cleaning professionals about the three P's of a robust cleaning and disinfection programs in public spaces. The three P's refer to:

  1. Training people and dedicating resources to the cleaning and disinfection process
  2. Selecting products to enable effective cleaning and disinfection
  3. Developing sustainable processes for creating and maintaining safer environments

Our new reality is that many more people are responsible for cleaning and disinfecting surfaces today, which means an increased need for education. The cleaning and disinfection world has its own lexicon and there are many nuances. The difference among cleaning and sanitizing and disinfecting is one example:

There are also a lot of questions around how to properly prepare and use surface disinfectants and where we should focus our disinfecting efforts.  In fact, a recent CDC report highlighted gaps in knowledge around the safe use of cleaning and disinfection products in household settings. In the survey of 502 U.S. adults, only 42% of respondents strongly agreed that they knew how to clean and disinfect their homes to help prevent the spread of the SARS-CoV-2 virus which causes COVID-19.

Because I understand firsthand how much people need additional education on cleaning and disinfection, I’m thrilled to be part of the Clorox team partnering with infection-control experts at the Cleveland Clinic to  develop free educational resources to help both consumers and professionals.1

Consumers looking for a comprehensive guide to help them protect themselves, loved ones and communities from further spread of COVID-19 can access Safer at Home: Your Guide to the Coronavirus Pandemic, which includes practical cleaning and disinfection tips for your home.

Employers and professionals looking for resources to help them ensure they’re leveraging best practices for cleaning and disinfecting in their workplaces can check out Six Building Blocks of a Robust Cleaning and Disinfection Program: A Guide for Employers. This guide contains a more in-depth approach for public spaces, including recommendations for organizational support, policies, procedures, product selection, staff training and monitoring.

There are always ways to enlighten ourselves about cleaning and disinfection best practices and do more to help control the spread of pathogens on hard, nonporous surfaces, and these resources are a great place to start.

1. The response to the coronavirus pandemic is continuously evolving as we learn more about the virus and the best techniques to address the associated risks. The Clorox Company has contributed its expertise to these guides in the areas of cleaning and disinfecting. All other guidance was developed through the expertise of Cleveland Clinic. Cleveland Clinic’s materials are based on currently available data and guidelines from the CDC and other resources as of July 29, 2020. This guidance may change from time to time and should be used only as a general reference.

As the COVID-19 pandemic continues, some companies are advertising cleaning services using antimicrobial products that they claim will continue to kill SARS-CoV-2 (the virus that causes COVID-19) on surfaces for days, weeks, or even months. Before you consider using these products or services, it’s important to understand what these claims really mean, what types of pathogens they relate to, and what claims the Environmental Protection Agency (EPA) does and does not allow. This article will help sort through the myths and facts around what are called residual or long-lasting claims.

What types of EPA-approved residual efficacy claims can a product have and what do they mean?

There are three types of residual, or long-lasting claims, that can appear on a product’s EPA approved master label (Table 1).

Table 1. Residual claims that may appear on a product’s EPA-approved master label

Note that all of these claims apply only to bacteria or fungi, and not to viruses. Therefore, these claims are not sufficient to support use against viruses, including SARS-CoV-2. Residual sanitization and residual disinfection claims are considered public health claims meaning they imply a direct impact on human health. These claims require data submission and approval before they can be listed on the product’s EPA master label. “Static” claims like “bacteriostatic,” “mildewstatic” and “fungistatic” are non-public health claims, meaning they do not imply a direct impact on human health. These claims do not require data submission to the EPA for approval at the federal level. However, some states may require data approval in order to make claims in that state.

What are “treated articles”?

In addition to antimicrobial products with residual claims, you may also encounter products with resistant or protection claims, known as treated articles. These treatments can be incorporated into surfaces (e.g., an odor resistant trash bag) or applied to surfaces (e.g., a protective surface coating) to protect the surface itself. The claims for treated articles are commonly used to address aesthetics such as discoloration, stains, or odors. Products that are found to have treated article claims will not have an EPA registration. According to the EPA, “treated articles cannot claim they are effective against viruses and bacteria that cause human illness. This means  they are not appropriate for controlling COVID-19.”1

How do I determine whether a product has EPA-approved residual efficacy claims?

To determine which residual efficacy claims a specific product carries, look up the EPA master label and search it for the key terms listed in Table 1. Products that do not make public health claims may not be EPA registered, and should not be used to kill microorganisms on surfaces. If the product is registered, here is how to find and search a product’s master label: 2

  1. Navigate to the EPA’s Pesticide Product Labeling System (PPLS) website.
  2. Enter the product’s EPA registration number into the field labeled “EPA Registration, Distributor Product, or Special Local Need Number:” and click “Search.” Companies should be able to provide this number to you, or it may appear on their product website. An example of an EPA registration number is “67619-38.”
  3. Open the most recent master label. The EPA includes the full history of master labels for each product, but only the most recent one will have all of the currently approved claims.
  4. Search the label for key terms. Terms like “residual disinfection,” “continuous disinfection,” “residual sanitization” or “residual self-sanitizer” must appear on labels that have approved residual sanitization or residual disinfection claims. Read the terms of the claim, including how often the product must be reapplied.

What is the EPA doing about residual claims in light of the pandemic?

The EPA recognizes the importance of residual kill claims against viruses in light of the COVID-19 pandemic, so they are investigating the possibility of adding these types of claims to certain product labels.3 However, until the EPA provides a clear path to obtaining residual efficacy claims against viruses, companies should not be advertising these types of claims.

Which products can I use against SARS-CoV-2?

For a full list of products that can be used against SARS-CoV-2, see EPA List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19).4 List N includes products that have demonstrated efficacy against:

All of these products are approved for disinfection of hard non-porous surfaces, but they should not be used for residual disinfection of viruses, including SARS-CoV-2.

To learn about EPA’s List N in an ever-changing environment, please read this blog post by Associate Research Fellow, Richard Lowe.


1. U.S. Environmental Protection Agency. Is there anything I can do to make surfaces resistant to SARS-CoV-2? https://www.epa.gov/coronavirus/there-anything-i-can-do-make-surfaces-resistant-sars-cov-2 (accessed Jul 20, 2020).
2. U.S. Environmental Protection Agency. Pesticide Product and Label System https://oaspub.epa.gov/apex/pesticides/f?p=PPLS:1 (accessed Jul 20, 2020).
3. U.S. Environmental Protection Agency. Longer-Term SARS-CoV-2 Disinfection Evaluation https://www.epa.gov/healthresearch/longer-term-sars-cov-2-disinfection-evaluation (accessed Jul 20, 2020).
4. U.S. Environmental Protection Agency. List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19) https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2-covid-19 (accessed Jul 24, 2020).

Let's Stay Connected

Get Our Updates


Get in Touch