New studies around the novel coronavirus have brought to light the need for updating the guidelines about how we keep ourselves safe from it and better manage the pandemic around the world. While one commentary highlights the possibility of airborne transmission, thus pointing towards the need for an update to hygiene practices, another research questions herd immunity, deeming it ‘unethical and unachievable’.
In a commentary published in the Clinical Infectious Diseases journal, experts urged the global community to identify the possibility of airborne COVID-19 infections. They argued that microscopic respiratory droplets can stay in the atmosphere for hours and drift several meters horizontally before they can infect people. These droplets can be generated when talking or breathing.
“By ‘airborne’ we mean that the virus can be transmitted by inhalation of microscopic droplets generated from breathing, talking, singing, and not just from coughing and sneezing,” said Don Milton, professor of environmental health at the University of Maryland and one of the commentary’s authors. “This does not mean that the virus can spread as easily over long distances as do measles or tuberculosis. Most transmission happens in closed, indoor spaces where there is poor ventilation, and crowding, and people are close together and talking loudly or singing without masks.”
While this does pose a significant threat, Lidia Morawska, the organizer of the commentary suggests that the solution can begin with simple things such as opening windows to ensure good ventilation to remove the virus from the air.
On the other hand, a new commentary in the Lancet pointed out that ‘any proposed approach to achieve herd immunity through natural infection is not only highly unethical but also unachievable’.
‘If 80% of a population is immune to a virus, four out of every five people who encounter someone with the disease won’t get sick (and won’t spread the disease any further). In this way, the spread of infectious diseases is kept under control. Depending on how contagious an infection is, usually, 70% to 90% of a population needs immunity to achieve herd immunity,’ according to an article by the Johns Hopkins Bloomberg School of Public Health.
The commentary authors also noted that seroprevalence studies provide information about only exposure data, but no information about immunity.