Breathing Is Enough: For the Spread of Influenza Virus and SARS-CoV-2 by Breathing Only

J Aerosol Med Pulm Drug Deliv. 2020 Aug;33(4):230-234. doi: 10.1089/jamp.2020.1616. Epub 2020 Jun 17.


Background: The transmission of respiratory viruses such as influenza and corona viruses from one person to another is still not fully understood. Methods: A literature search showed that there is a strong scientific rationale and evidence that viruses are very efficiently spread through aerosols by the patient's breathing only. It is not necessary for the patient to cough or sneeze. Results: The exhaled aerosol particles are generated by normal breathing in the deep lung through reopening of collapsed small airways during inspiration. These mucus/surfactant aerosols (size range between 0.2 and 0.6 μm) can transport viruses out of the lungs of patients and be present in the room air for hours. Conclusion: These aerosol particles are difficult to filter out of the air; because of their physical properties, new strategies must be developed to protect people from these virus aerosols.

Keywords: SARS-CoV-2; exhaled aerosols; influenza; virus transmission.

Publication types

  • Letter
  • Review

MeSH terms

  • Aerosols*
  • Betacoronavirus
  • COVID-19
  • Coronavirus Infections / transmission*
  • Humans
  • Pandemics
  • Personal Protective Equipment
  • Pneumonia, Viral / transmission*
  • Respiration*
  • SARS-CoV-2


  • Aerosols