By Mary Hearty

In order to break the chain of COVID-19 transmission globally, at least 60 to 70 percent of the population needs to have the immunity, according to Dr Soumya Swaminathan, Chief Scientist at World Health Organization (WHO).

“This can be accomplished naturally by letting the infection run wild in the population and infect many people. However, it will take a long time and most importantly, it will do a lot of collateral damage,” she notes during a virtual press conference.

“That is why we believe it is not a good idea to try to achieve herd immunity through natural infection. And so naturally, the better choice is doing it through a vaccine.”

Dr. Swaminathan added: “To achieve herd immunity in the population, for measles, about 95 percent of this population need to have immunity or antibodies. So, even if the remaining 5 percent of children are not vaccinated, these others have enough protection in the population to prevent measles virus from spreading.”

According to the chief scientist there are actions that countries can use to slow down transmission despite many lacking therapeutics for COVID-19 right now.

“These include public health and measures put in place like, physical distancing, wearing a mask when in crowded settings, washing hands frequently,” she said.

“And on the side, be able to detect rapidly those who are infected in the community, making sure that enough testing is available, be able to isolate them, then test their contacts and quarantine them. They are difficult to implement but it is worth doing, since this helps to save lives until the time that we have more effective medicines to treat this disease and, of course, a safe and effective vaccine.”