WHO acknowledges emerging evidence that Covid-19 is airborne

Published July 14, 2020, 12:13 PM

by Krizette Laureta-Chu

How will this change the way we protect ourselves? 

Recently, 239 scientists from 32 countries penned an open letter to the World Health Organization, declaring there is mounting evidence the airborne route plays a role in the transmission of Covid-19. The scientists suggest WHO has been underplaying the role of airborne transmission.

To this day, the WHO has maintained that the primary source of infection is droplets, though it has released an updated guidance on the role of airborne droplets in transmission of Covid-19. While it acknowledges the evidence presented by scientists, WHO is yet to issue a confirmation. 

Speaking at a briefing in Geneva on July 7, Benedetta Allegranzi, the WHO’s technical lead for infection prevention and control, said that while there is evidence of airborne transmission, it is not definitive. “The possibility cannot be ruled out,” she said. “The evidence, however, needs to be gathered and interpreted, and we continue to support this.” 

Nevertheless, this new development is causing a ripple of panic and confusion worldwide. Right now, it would seem like there’s nothing more we could do to keep Covid-19 at bay. We’re already suiting up in our PPEs, wearing masks as soon as we step out of our houses, outfitted with face shields, and washing our hands obsessively. We are maintaining social distance, many of us are staying inside our homes even to the detriment of our jobs, and we’ve bought UV lights, hands-free alcohol dispensers, sanitizing mats, and everything else believed to “kill” the virus.

So what are the implications?

Simply put, airborne transmission means the virus can be spread by aerosols—droplets that are very small in size (five micrometers)—that are small enough to hang suspended in the air.  

If droplets can only travel short distances, aerosols can be spread further and even linger in the air, even after an infected person has left the room.

Social distancing was deemed important because scientists previously believed that transmission was through droplets, and as long as you stayed far away from a person who had Covid-19, the droplet would not be able to reach you as it is heavy and will fall to the ground. 

If the virus is airborne, it would mean that the aerosol can hang in the air for up to three hours—a scary possibility because some people, upon entering an empty room, may be lulled into a false sense of security and remove his mask.

Scientists now want WHO to update its guidelines and warn people that the virus may be transmitted not only within six feet but up to several meters inside indoor spaces. The WHO has acknowledged the mounting evidence, but says it will announce its findings and stand in the following days. 

How can you protect yourself?

While the airborne debate still hangs in the air, people are worried and panicked about the measures they’re taking to keep themselves safe, considering many have gone all out in protecting themselves.

Assuming it is airborne, the bottomline is: The risk is greatest in indoor environments—think restaurants and other crowded areas like small groceries—where air does not circulate well. Small particle aerosols in these venues will stay aloft in the air for a significant period. Avoid all small indoor places when you can, crowded places, and superspreader events, like the major outbreaks at a choir practice in Skagit Country and a soccer match in Italy. Most outbreaks have occurred in indoor environments. Outdoors, aerosols can dissipate quickly. 

Another major difference: Since aerosolized droplets containing viral particles are likely to remain in poorly ventilated rooms for up to several hours, do not let your guard down even when you are indoors, and even when you think you’re the only person or group in a restaurant. 

“What does this renewed debate mean for the general public? It means that we have to be extra careful with Covid-19,” says Dr. Edsel Salvanaan infectious diseases specialist and molecular biologist at the University of the Philippines and the Philippine General Hospital. “It means that because Covid-19 has the potential to have airborne characteristics, we have to bemeticulous with cloth or surgical mask wearing and minimize crowding, especially in areas with poor ventilation. Avoid talking without a mask, especially in enclosed spaces like elevators. Singing has also been implicated in superspreader events, so no karaoke for now. Do not eat together at work as this has also been associated with clusters.” 

Does this mean you have to upgrade to wearing N95 masks? “N95 masks only work well if they are specially fitted and there are different sizes,” adds Dr. Salvana, who is also the director of the Institute of Molecular Biology and Biotechnology at the National Institutes of Health at UP Manila. “They are also very uncomfortable for long periods of time and are expensive. An N95 that is not properly fitted is no better than a surgical mask.Studies have shown that surgical masks already decrease risk of transmitting Covid-19 by 85 percent. There is not enough evidence that N95 masks will be useful for the general public.” 

When indoors, one simple thing people can do is to open their windows and doors.

Businesses, schools, or offices may consider upgrading the filters in their air conditioning systems, clinics and public offices may need to invest in air purifiers and ultraviolet light that can kill the virus, and—this is breaking news—you may want to stock up on Lysol.

Feel free to spritz a room you’re entering with Lysol. The US Environmental Protection Agency has approved two Lysol products as effective against the novel coronavirus when used on hard, non-porous surfaces. Lysol Disinfectant Spray and Lysol Disinfectant Max Cover Mist met the EPA’s criteria for use against the SARS-CoV-2, based on laboratory testing that found both products kill the virus two minutes after contact, the agency announced in a statement Monday.

Dr. Salvana offers some sobering advice—and perspective—as citizens scramble with this information: “This possibility of airborne transmission is not new, and even if the evidence is far from definitive, it is always prudent to take precautions, within reason. There is no need to use N95 masks unless you are a healthcare worker, but everyone else needs to be meticulous with cloth or surgical mask wearing. Avoid crowded areas and enclosed spaces with poor ventilation. Limit trips outside the house and practice physical distancing, work from home if possible, and disinfect regularly. Covid-19 is beatable if we all work together and if everyone does the right thing to protect each other.”