What does 'coronavirus is airborne' mean? WHO Chief Scientist Dr Swaminathan explains

The World Health Organisation's (WHO) Chief Scientist Dr Soumya Swaminathan said coronavirus can survive in air and transmit but "in a very limited environment". Her statement came after a concerning report by a group of scientists from 32 nations who claimed that coronavirus was airborne.

In an interview to India Today, Dr Swaminathan explained airborne transmission, she stated that when humans speak, shout, sing or even breathe, droplets of different sizes make way into the air. Larger droplets fall within 1-2 metre but smaller droplets of 5 microns don't immediately settle on the ground, she says. Smaller droplets are called aerosols and since they are small in size, they can stay in the air for 10-15 minutes and can be moved around by gusts of winds, Dr Swaminathan told the channel. Therefore, these particles could be inhaled by other people who are in the vicinity, she added.

"If you happen to enter that space and breathe that air, you may get infected because the tiny droplets containing the virus are still in the air," she said.

However, according to Dr Swaminathan, the aforementioned form of airborne transmission was very different from the transmission of diseases like measles. According to her, "Measles are truly airborne in the sense that they spread primarily in the air".

Dr Swaminathan explained that the airborne transmission could happen but in "special situations". "We don't say it doesn't happen. But it does not mean that since COVID-19 is airborne, it means it is everywhere and nothing can be done. If it was truly airborne like measles, in the sense that it was everywhere, all of us would have been infected by now," Dr Swaminathan said.

The chief scientist at WHO added that the majority of the transmission occurred from droplets. However, there was a possibility to control more number of coronavirus cases by maintaining social distancing, and other means.

On Tuesday, the WHO acknowledged that there was an emerging evidence of the airborne spread of coronavirus.

"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 said.

The WHO has previously said the virus that causes the COVID-19 respiratory disease spreads primarily through small droplets expelled from the nose and mouth of an infected person that quickly sink to the ground.

But in an open letter to the Geneva-based agency, published on Monday in the Clinical Infectious Diseases journal, 200 scientists outlined evidence that they say shows floating virus particles can infect people who breathe them in.

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