Some level of herd immunity can be achieved by the end of 2021

SINGAPORE – The world must remain vigilant for the next six months, while the coronavirus vaccine is launched, as it will take some time before the majority of the population receives the vaccines, the chief scientist of the World Health Organization told CNBC.

“We are going to approach the beginning of the end, we can see the light at the end of the tunnel,” said Dr. Soumya Swaminathan on Wednesday. “However, there is still a tunnel that we have to go through and the next few months will be very critical.”

Confirmed cases of Covid-19 continued to increase at an alarming rate, with global infections reaching 78 million, according to data compiled by Johns Hopkins University.

The Pfizer-BioNTech vaccine has been approved for emergency use in countries such as the United Kingdom, USA and Canada, while the USA has also approved Moderna.

Although we can expect – certainly until the end of next year – a much better picture, the next few months, I think, will be difficult.

Soumya Swaminathan

Chief Scientist of the World Health Organization

Swaminathan said that vaccines will initially protect a very small group of people who are most vulnerable and at greatest risk, and months will pass before the rest of the population can be covered.

“It will be until the end of 2021 before we start to see some level of population immunity arriving in some countries,” she told CNBC’s “Street Signs Asia” on Wednesday.

“We have to keep our guard up, we have to do all the things we know to reduce transmission and the chances of people getting sick,” she said. This includes public health measures and individual behavioral changes.

“Although we can expect – certainly by the end of next year – a much better picture, the next few months, I think, will be difficult,” she added.

New strain in the UK

Separately, Swaminathan discussed a new variant of the virus that emerged in the UK recently and has been identified in countries like Australia, Denmark and Italy.

She said it is unusual because it has a large number of mutations and has separated from the average strain.

“What is most worrying is that there are about eight mutations in the spike protein region,” she added. The virus’s spike protein clings to receptors found on the surface of human cells in the respiratory tract, or to the ACE2 receptor in the case of Covid-19. Mutations have been detected in the part of the protein that binds to receptors in the respiratory tract.

“This is probably the reason why this virus seems to have an advantage in infecting people, it seems to be transmitting more efficiently, it seems to infect children who have fewer of these receptors,” she said.

People wear face masks while shopping at Union Square Greenmarket on December 4, 2020 in New York City.

Noam Galai | Getty Images Entertainment | Getty Images

But she noted that the new variant “does not appear to increase clinical severity or make things worse” for those who are infected with it.

The WHO said in a note that the strain may “spread more quickly” but that “there is not enough information at the moment” to determine whether the mutations will alter the severity of the disease, the response of the antibodies or the effectiveness of the vaccine.

Swaminathan said “there is no reason” to believe that current vaccines will not cover the problem at the moment. That’s because vaccines produce a “broad immune response” that is likely to be effective against the new strain.

Still, if vaccines need to be adjusted, it can be done “easily”. “If there is a need, it can be done,” she said. “But at the moment, I think most people believe that the current generation of vaccines should work well.”