Fight COVID-19 With Humidifiers

Virologists, Doctors, and the Center for Disease Control and Prevention recommend humidifiers as a solution to battling airborne viruses with higher humidity levels. 

In this article, we'll cover CDC's recommendations, provide you with an Optimal Humidity Chart, and shed light on the current Coronavirus-19 Outbreak. 

Treating Coronavirus with Humidifiers 

Information from the Center for Disease Control and Prevention

The following information was obtained from CDC’s website

How COVID-19 Spreads

According to the CDC, the COVID-19 virus is thought to spread person-to-person, between people who are in close contact with one another (within about 6 feet) or through respiratory droplets produced when an infected person coughs or sneezes.

It may also be possible to contract the virus by touching a surface or object that has the virus on it, and then touching the mouth, nose, or eyes.


Symptoms may appear 2-14 days after exposure and include fever, cough, and shortness of breath.


There is currently no vaccine to prevent COVID-19. The CDC recommends the following precautions to help prevent the spread of respiratory diseases:

  • Avoid close contact with people who are sick
  • Avoid touching your eyes, nose, and mouth
  • Stay home if you are sick
  • Cover your cough or sneeze with a tissue, and then throw the tissue away
  • Clean and disinfect frequently touched objects/surfaces
  • Wash your hands often with soap and water for at least 20 seconds, especially after going to the bathroom, before eating, and after blowing your nose, coughing, or sneezing

Face Masks

  • CDC does not recommend that people who are not sick wear a facemask to protect themselves from COVID-19.
  • Facemasks should be used by people who show symptoms of COVID-19 to help prevent the spread of the disease to others. This is crucial for health workers and people who are taking care of someone in close settings. 

Treatment for Flu and Upper Respiratory Illnesses

  • Seek medical attention to get appropriate testing.
  • To keep your blood pressure in check, avoid over-the-counter decongestants and multisymptom cold remedies that contain decongestants — such as pseudoephedrine, ephedrine, phenylephrine, naphazoline, and oxymetazoline.
  • If your physician thinks that your respiratory symptoms could be helped by antibiotics, do not take fluoroquinolones a commonly prescribed class of antibiotics. These drugs should not be used in people with certain genetic conditions that are associated with aortic aneurysms and dissections such as Marfan syndrome and other genetic aortic conditions. The antibiotics in this class are Avelox, Cipro, Factive, Levaquin, and Ofloxacin.
  • Choose a cold medication designed for people who have high blood pressure. Some cold medications don't contain decongestants. However, these medications may contain other powerful drugs, such as dextromethorphan, that can be dangerous if you take too much. Follow the dosing instructions carefully.
  • Take a pain reliever such as acetaminophen to relieve a fever, sore throat, headache or body aches. 
  • To relieve nasal congestion, try a saline nasal spray. The spray can help flush your sinuses.
  • Soothe your throat. To relieve a sore or scratchy throat, gargle with warm salt water or drink warm water with lemon juice and honey.
  • Drink plenty of fluids. Water, juice, tea, and soup can help clear your lungs of phlegm and mucus.
  • Increase the humidity in your home. Use a cool-mist humidifier or vaporizer to moisten the air, which may ease congestion and coughing.
  • Get plenty of rest. If you're not feeling well, take it easy. 

What can the public do to defend against the COVID-19 coronavirus? 

One simple answer is to ramp up humidification at home and in the workplace if humidity levels are low. Hospitals treating cases of viral respiratory infection may be advised to do the same.

Why has the novel coronavirus COVID-19 had only a minimal impact in tropical countries while temperate zone countries such as China, Korea, Italy, Iran, and the United States have suffered outbreaks? Humidity, and especially indoor humidity, seems to hold the key.

In 2019, a research team at Yale University Medical School published a groundbreaking study (Kudo et al., National Academy of Sciences, 2019) which showed how low ambient humidity hurts the ability of the immune system to fight a respiratory viral infection in animal hosts. As Yale immunologist Akiko Iwasaki repeatedly has tweeted, winter months require indoor heating, which leads to low indoor humidity, which in turn leads to reduced mucociliary clearance and innate antiviral immunity, resulting in more respiratory virus in the lungs and increased mortality.

Dr. Nancy Gough of Johns Hopkins University explained the Yale study thus (Medium, March 1, 2020): “When the temperature drops, the heat comes on. This reduces the amount of humidity in the air. It turns out this isn’t just uncomfortable; it also impairs the innate immune system in the respiratory tract.”

What do all the places with severe community COVID-19 outbreaks have in common? As a  group of U.S. and Iranian researchers (Sajadi et al. (2020)) concluded in a new study posted for review on March 9, 2020, “To date, Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2, has established significant community spread in cities and regions only along a narrow east-west distribution roughly along the 30-50 N” corridor at consistently similar weather patterns”. In each of the locations of significant community spread identified by the researchers, indoor humidity ranged from about 20% to 30% in the weeks prior to the outbreak, which is fairly dry. “Because of geographical proximity and significant travel connections, epidemiological modeling of the epicenter predicted that regions in Southeast Asia, and specifically Bangkok would follow Wuhan, and China in the epidemic.” Instead, the researchers noted, “COVID-19 failed to spread significantly to countries immediately south of China.”

Dr. Gough further explained the importance of humidity, “The epithelial cells have small cellular protrusions called cilia that move the mucus to promote clearance of pathogens and particles that enter the respiratory system. Analysis of the mucus in the trachea showed that infection in low humidity resulted in the inability of the cilia on the epithelial cells to move it. The low humidity made the mucus too thick.”

What can you do when low humidity is unavoidable? Explained Dr. Iwasaki, “A mask will certainly keep your nose and mouth warmer and more humidified. I always wear a mask on international flights for this reason, where 10% relative humidity and closed environment makes for a perfect transmission incubator.”

What should be the target humidity? The Yale team found that 50% ambient humidity at room temperature led to dramatically increased survival in their animal subjects. What if a humidifier is not available? A large pot of water carefully kept at a low boil can humidify dry winter air to healthy levels.

This research suggests that warmer, more humid weather will soon bring relief to countries now affected by COVID-19. Until then, indoor humidification and the use of facemasks may save many lives and ultimately help the world turn the corner in the fight against this epidemic.

Additional Information on the Seasonal Flu and COVID-19

Flu season is in full swing and it seems to be only getting worse with Coronavirus (COVID-19) spreading like wildfire across the globe with new cases every day. As of today, COVID-19 has the highest mortality rate, so please make sure you're doing everything you can to limit your chances of getting in contact with this highly contagious virus.

Local municipalities are taking precautionary measures to respond to the massive outbreak. We're seeing schools, restaurants, and even the professional sports associations closing their doors to the public in an effort to minimize the spread of the highly contagious Coronavirus.

While municipalities are taking the necessary steps to minimize the risk of spreading the flu and the virus, there are also effective precautionary measures your family can take.

One of the most important things you can do is follow the advice of CDC and your local government's preventative measures (social distancing, self-quarantine, limiting gatherings, regular sanitation, staying away from places where there are more than 10 people, etc.) 

Another thing you can do is keep your indoor humidity levels between 50-60% - airborne viruses can't survive in such environments. 
Humidity Level Chart




Key Citations:

  1. Kudo et al. (2019) Low ambient humidity impairs barrier function and innate resistance against influenza infection. Proceedings of the National Academy of Sciences, 2019
  2. Gough, March 1, 2020. Fighting the Flu with Humidity: Researchers discover immune system benefits of humidity Fighting the Flu with Humidity Researchers discover immune system benefits of humidifying-the-flu-with-humidity-28d4ccb42bd7
  3. Sajadi et al. (2020) Temperature and Latitude Analysis to Predict Potential Spread and Seasonality for COVID-19

Further reading:

    1. Makinen et al. (2009) Cold temperature and low humidity are associated with increased occurrence of respiratory tract infections. Respiratory Medicine, Volume 103, Issue 3, March 2009, Pages 456-462
    2. Salah et al. (1988) Nasal mucociliary transport in healthy subjects is slower when breathing dry air. Eur Respir J. 1988 Oct;1(9):852-5.
    3. Shaman et al. (2009) Absolute humidity modulates influenza survival, transmission, and seasonality. PNAS March 3, 2009 106 (9) 3243-3248
    4. Lowen et al. (2007) Influenza virus transmission is dependent on relative humidity and temperature. PLoS Pathog 3(10): 1470–1476.
    5. Yang et al. (2011) Dynamics of airborne influenza A viruses indoors and dependence on humidity. PloS One 6(6): e21481.

    6. Center for Disease Control and Prevention (CDC) - recommends Air Humidifiers to combat Coronavirus and the Common Flu.


Image Source:

      1. Center for Disease Control and Prevention (CDC) (2020) - Recommends Air Humidifiers to combat Coronavirus and the Common Flu -

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