Recently, the conversation around COVID-19 has been centred on how the virus is spread. While it was initially thought that the virus is not airborne, that sentiment has slowly been changing, with mounting evidence pointing to the airborne nature of the disease.
This came after a letter, co-signed by 239 scientists and engineers, was published in the journal Clinical Infectious Diseases, calling for public health agencies, including the World Health Organisation (WHO), to consider the possibility of the virus being airborne.
In their letter, they wrote:
“We appeal to the medical community and to the relevant national and international bodies to recognise the potential for airborne spread of COVID-19. There is significant potential for inhalation exposure to viruses in microscopic respiratory droplets at short to medium distances (up to several metres, or room scale), and we are advocating for the use of preventative measures to mitigate this route of airborne transmission.”
The letter went on to say that this is a matter of urgency now as countries are starting to ease lockdown regulations.
The WHO’s position
The WHO has confirmed that airborne transmission can happen in healthcare settings where specific medical procedures, called aerosol-generating procedures, generate very small droplets called aerosols. As for the general public, it’s not yet 100% certain.
“Outside of medical facilities, some outbreak reports related to indoor crowded spaces have suggested the possibility of aerosol transmissions, combined with droplet transmission, for example, during choir practice, in restaurants, or in fitness classes,” the WHO said.
“In these events, short-range aerosol transmission, particularly in specific indoor locations, such as crowded and inadequately ventilated spaces of a prolonged period of time with infected persons cannot be ruled out.”
What if it is airborne?
The letter clearly outlines that airborne transmission is especially acute in indoor or enclosed environments, particularly those that are crowded and have inadequate ventilation relative to the number of occupants and extended exposure periods.
“For example, airborne transmission appears to be the only plausible explanation for several super-spreading events investigated which occurred under such conditions and others where recommended precautions, related to direct droplet transmissions, were followed,” the letter says.
They agree that there is incomplete evidence, but add that there is more than enough supporting evidence so that the precautionary principle should apply. Their suggested precautionary measures (over and above those already existing) include:
- Provide sufficient and effective ventilation (clean outdoor air, minimise recirculating air) particularly in public buildings, workplace environments, schools, hospitals and aged care homes.
- Supplement general ventilation with airborne infection controls such as local exhaust, high-efficiency air filtration and germicidal ultraviolet lights.
- Avoid overcrowding, particularly in public transport and public buildings.
It might not be clear whether an airborne transmission is something to be concerned about as yet, but with a virus as unpredictable as this one, taking precautionary measures more seriously, including avoiding indoor spaces with a lot of people in them, should be the order of the day.
Russia completes pre-clinical trials for COVID-19 vaccine
Just recently, Russia’s Vektor State Research Centre for Virology and Biotechnologies announced that it had successfully completed pre-clinical trials of a vaccine for COVID-19.
“Colleagues have finished pre-clinical trials [and] they were successful. We practically have all the grounds to be sure that things will go as we promised [meaning] that we plan to begin clinical trials on July 15,” Anna Popova, chief of the Russian sanitary watchdog, said on Friday.
This announcement was widely celebrated across the world, including South Africa, with citizens taking to Twitter to share how ‘excited’ they were about the prospect of finally putting an end to the pandemic. But the minister of health Dr Zweli Mkhize quickly reminded South Africans that the road ahead is still long.
“You have to do work at the laboratories, do research, move to animal studies, and it passes that, you have to move to a human trial,” he said in a statement.
“The same trial is going on in the US, UK, Brazil and other countries. We’re not yet at a point where we’ve got a vaccine ready – it is good news, but it is still a work in progress and it’s still early days.”
SA could have vaccine as early as 2021
One of the 19 vaccines being tested on humans globally is happening right here in South Africa. Led by professor of vaccinology at the University of Witwatersrand Dr Shabir Madhi, it’s believed that if everything goes as planned, the vaccine could be ready early 2021.
“A vaccine could be made commercial as early as the beginning of next year, but it is completely dependent on the results of the clinical trials.”