A certain level of immunity of the herd can be reached 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 for the majority of the population to receive vaccinations, the World Health Organization chief scientist told CNBC.

“We will get closer to the beginning of the end, we can see the light at the end of the tunnel,” Dr. Soumya Swaminathan said on Wednesday. “However, we have to go through another tunnel, and the next few months will be very critical.”

Cases confirmed by Covid-19 continued to grow at an alarming rate, with global infections exceeding 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, the United States and Canada, while the United States has also approved Moderna.

Although we can look forward – certainly by the end of next year – to a much better picture, the next few months, I think, will be difficult.

Soumya Swaminathan

World Health Organization scientist

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

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

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

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

The new strain in the UK

Separately, Swaminathan discussed a new variant of the virus that has recently appeared in the United Kingdom and has been identified in countries such as 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’s more worrying is that it has about eight mutations in the spike protein region, she added. The spike protein of the virus binds to receptors on the surface of human cells in the respiratory tract or to the ACE2 receptor in Covid-19. Mutations in the protein that binds to respiratory receptors have been detected.

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

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

Noam Galai | Getty Images Entertainment | Getty Images

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

The WHO said in a note that the strain could “spread more easily”, but that “there is not enough information at present” to determine whether the mutations will change the severity of the disease, the antibody response or the effectiveness of the vaccine.

Swaminathan said there was “no reason” to believe that the current vaccines would not cover him at this time. This is because vaccines produce a “broad immune response”, which is likely to be effective against the new strain.

However, if vaccines need to be modified, this can be done “easily”. “If needed, it could be done,” she said. “But right now, I think most people think the current generation of vaccines should work very well.”