UK ‘can’t be confident’ of avoiding another Covid wave despite vaccine success, says leading epidemiologist

“We are in a period where we can’t be confident that we won’t see large numbers of infections”, Professor Adam Kucharski says

We cannot yet be confident that Britain’s vaccination programme will prevent the possibility of another coronavirus wave, despite the success of the rollout so far, a top epidemiologist has said.

Speaking to BBC Radio 4’s World At One, Professor Adam Kucharski, an epidemiologist at the London School of Hygiene and Tropical Medicine said he could not say with certainty that the vaccine programme would guard against “large numbers” of fresh Covid-19 infections.

Even if the vaccination program sees 95 per cent of the population aged over 65 protected, he explained that could still mean seeing as many as 600,000 new cases among those in the most vulnerable groups.

“I think in the coming weeks, we’re going to get a lot more information about the characteristics of these vaccines, how well they are working in real life - there are a lot of detailed studies going on to try and measure that,” Prof Kucharski said.

“So I think at the moment we are in a period where we can’t be confident that we won’t see large numbers of infections - we can’t be totally confident about what that will look like and there [are] obviously different scenarios being studied,” he said.

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The epidemiologist issued a similar warning in a Twitter thread on Sunday, in which he explained that he had seen some people “making the mistaken assumption that once a group that make up X per cent of COVID hospitalisations/deaths are vaccinated, it will reduce hospitalisations/deaths by the same per cent, even if control measures are lifted.”

Arguing against such claims, he added “If we remove 50 per cent of the hospitalisation risk within a population through vaccination, for example, but have a large increase in level of infection, it could mean no reduction (or even an increase) in overall hospitalisations”.

The expert in finding mathematical and statistical approaches to disease outbreaks added that “vaccination won’t necessarily reduce risk of severe outcomes by 100 per cent if infected.”

“We all hope effectiveness is high, of course, but it’s still unclear exactly what the level of protection will be several months down the line,” he said.

Professor Kucharski said it was important to remember the role that current coronavirus measures are having on reducing the spread of Covid-19.

“Recent hospitalisations/deaths only reflect [a] fraction of people potentially at risk of that outcome if infection levels were much higher,” he said. Lifting coronavirus measures without caution could change that.

The warning comes as the Johnson government marks the milestone of seeing 15 million people in the four priority groups receive at least one dose of the coronavirus vaccine.

On Monday, Boris Johnson said his government was making plans to move England out of lockdown in an effort that he said will be “cautious, but irreversible”.