As the coronavirus pandemic wreaks havoc around the world, a question that has often been asked is if it is airborne or not. This question has recently been thrown back into the limelight by a group of 239 scientists from 32 countries, who addressed a letter to the World Health Organization(WHO) arguing against WHO’s guidelines of coronavirus not being airborne, and asking it to revise its position in the backdrop of mounting evidence that coronavirus IS, in fact, airborne in crowded indoor spaces.
WHO has repeatedly brushed off the idea that coronavirus might be spreading through the air. However, on Thursday, WHO came out with an updated version of the guidelines of its March 29 coronavirus brief; formally confirming that the novel coronavirus can remain in the air in crowded, inadequately ventilated indoor spaces, where “short-range aerosol transmission cannot be ruled out”.
What did WHO say?
The development comes days after WHO acknowledged a possibility of the coronavirus being airborne on Tuesday, albeit stating the evidence regarding the same is not yet definitive. In a press briefing in Geneva, WHO’s technical lead for infection prevention and control, Benedetta Allegranzi said,
“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.”
Changing their previous statements, WHO noted that researches exploring COVID-19 outbreaks in fitness classes, restaurants, etc. suggesting the airborne transmission of coronavirus might be headed in the right direction. It noted that crowded spaces that have been exposed to infected persons may still have virus particles if they’re not properly ventilated. But it also pointed out that other modes of transmission— like close contact between people and contaminated surfaces in such environments— could have been at play either.
In their updated guidelines, WHO finally corrected its position and recognized the role played by asymptomatic people in the transmission of COVID-19, a phenomenon it has long downplayed. This comes as a relief after WHO had previously denied this kind of transmission vehemently despite a growing majority of scientists who thought otherwise. The agency stated on Thursday,
“Infected people can transmit the virus both when they have symptoms and when they don’t have symptoms, however, its true extent remains unknown.”
COVID-19 and its airborne transmission
For the uninitiated, airborne transmission is defined as the faculty of a virus to be transmitted by droplets that are small enough to remain suspended in the air. These droplets, called aerosols, are less than 5 micrometers in size, hence invisible to the naked eye. Dictated by common sense, the larger droplets cannot cover larger distances as opposed to smaller droplets that can linger in a room for a longer period, and even after the infected person has left.
Various evidence has cropped up supporting this notion of coronavirus being airborne.
Firstly, various laboratory studies conducted to understand the DNA makeup of SARS-CoV-2, the v RNA that causes corona, have suggested that it can be aerosolized and might even survive up to four hours in said form.
Secondly, from two hospitals in Wuhan, the hot-spot Chinese city of the pandemic, the genetic material of SARS-CoV-2 has been detected in their aerosols. Despite this, it isn’t known if the virus is infectious in this form.
Perhaps, the strongest of all evidence is how the novel coronavirus spread like wildfire and a constant pattern of super-spreading events can be noted throughout the world. In these instances, a large number of people appear to have been infected by the coronavirus despite the absence of close, personal contact.
What are the implications of this discovery?
The airborne nature of coronavirus will prove to be a huge setback in the fight against corona as it means the social-distancing norms will have been for nothing as the virus can fastly transmit even in the absence of personal contact. It also raises a scarier possibility that the virus is probably traveling through air currents, and might even be transmitting through appliances like air conditioners, humidifiers.
What does this mean for us?
Now that it’s clear that airborne transmission is possible, the problem is finding out the significance of its role in spreading COVID-19.
What needs to be determined is that if the significant mode of transmission of SARS-CoV-2 is airborne or through droplets. If the airborne transmission were the major mode then it would entail a very different reality for the world in the near future. But since social distancing measures and lockdowns have turned out to be successful in various parts of the world if implemented correctly, it points towards the droplet mode being the major route of transmission, with the airborne route playing a role occasionally. But, this is just conjecture unless the research is done to support the argument.
How has the Indian government reacted to this?
Continuing to deny the community transmission of COVID-19 in India, the Union Health Ministry said on Thursday that it is “intently watching the complex development of the pandemic situation of the country, with the World Health Organisation (WHO) now confirming that the virus could be in the air.”
“We are keeping up with the details coming from WHO headquarters on this issue,” Rajesh Bhushan, OSD, Union Health Ministry, stated in a press briefing on Thursday, explaining that India is presently experiencing what can be called a localized virus epidemic in different regions of the country.
Mr. Bhushan declined to comment on the preceding assertion to be capable of delivering an indigenous vaccine by 15 August by the Indian Council of Medical Research (ICMR). The spokesman added that two Indian firms — Bharat Biotech and Cadila Healthcare — have been designing vaccines and both have completed research on animal toxicity.
The key dilemma that remains to be addressed is if countries should take a stringent approach and precautionary measures, by assuming that the airborne route is the major mode of transmission— and adjust their policies of infection control accordingly.
Or, to remain as they are in their approach to battle corona and wait for more definitive evidence before changing the rules of the game.