WHO Confirms COVID19 could be Airborne! What Does Airborne Transmission Mean? Report

The World Health Organization (WHO) confirmed on Tuesday that there is “evidence emerging” which suggests that coronavirus could be airborne. This acknowledgment comes after a group of scientists urged the health agency to update its guidance on how the respiratory disease transmits. 

"We have been talking about the possibility of airborne transmission and aerosol transmission as one of the modes of transmission of COVID-19," Maria Van Kerkhove, technical lead on the COVID-19 pandemic at the WHO, told a news briefing.

The WHO had previously stated that COVID19 primarily spreads through small droplets expelled from the nose and mouth of the infected person and it quickly sinks into the ground due to gravity. 

Contrary to that, an open letter in the Clinical Infectious Diseases Journal published by 239 scientists in 32 countries elucidated evidence that underlines that floating virus particles can infect people who breathe them in. 

"...The possibility of airborne transmission in public settings - especially in very specific conditions, crowded, closed, poorly ventilated settings that have been described, cannot be ruled out. However, the evidence needs to be gathered and interpreted, and we continue to support this,”Maria Van Kerkhove said.

What does Airborne Transmission Mean?

Respiratory infections such as COVID19 spread through droplets of different sizes. When the droplets particles are larger than 5-10 microns in diameter, they are called respiratory droplets and if they are smaller than 5 microns in diameter, they are called as droplet nuclei. “According to current evidence, Covid-19 virus is primarily transmitted between people through respiratory droplets and contact routes,” the WHO states.

However, the letter which was written by scientists state that aerosol transmission too can happen. WHO is of the view that if the droplets are larger than 5-10 microns in diameter, it will eventually fall to the ground due to gravity, after travelling for less than 1 metre.

Whereas, the scientists believe that even droplet nuclei that are less than 5 microns in diameter can have the virus and travel for longer than 1 metre and eventually stay in air for a longer time. If this is true, the risk of transmission will be higher than what it was previously.