It is not yet clear whether or not the world needs a new set of vaccines to fight different variants of the novel coronavirus but scientists are working on new ones so there is no reason for alarm, the head of the Oxford Vaccine Group said on Tuesday.
"There are definitely new questions about variants that we're going to be addressing. And one of those is: do we need new vaccines?," Andrew Pollard, Chief Investigator on the Oxford vaccine trial, told BBC radio.
"I think the jury is out on that at the moment, but all developers are preparing new vaccines so if we do need them, we'll have them available to be able to protect people."
Mr Pollard's team developed the Oxford/AstraZeneca vaccine.
South Africa paused a planned rollout of AstraZeneca's Covid-19 vaccinations after data showed it gave minimal protection against mild infection from one variant, stoking fears of a much longer cat-and-mouse battle with the pathogen.
No reason for alarm
Researchers from the University of Witwatersrand and the University of Oxford said in a prior-to-peer analysis that the AstraZeneca vaccine provided minimal protection against mild or moderate infection from the South African variant among young people.
"I think there's clearly a risk of confidence in the way that people may perceive you. But as I say I don't think that there is any reason for alarm today," Mr Pollard said.
"The really important question is about severe disease and we didn't study that in South Africa, because that wasn't the point of that study, we were specifically asking questions about young adults."
The so-called South African variant, known by scientists as 20I/501Y.V2 or B.1.351, is the dominant one in South Africa and is circulating in 41 countries around the world.
Other major variants include the so-called UK variant, or 20I/501Y.V1, and the Brazilian variant known as P.1.
It needs a relook at how best to deploy the vaccine
An analysis of infections by the South African variant showed there was only a 22 per cent lower risk of developing mild-to-moderate Covid-19 if vaccinated with the AstraZeneca shot versus those given a placebo.
If vaccines do not work as effectively as hoped against new and emerging variants, then the world could be facing a much longer - and more expensive - battle against the virus than previously thought.
Mr Pollard said the South African government was correct to look at how they deploy the AstraZeneca vaccine because their original plan was to deploy it in young adults - particularly healthcare workers - who were not expected to get severe disease.
"It needs a relook at how best to deploy the vaccine," Mr Pollard said.