A Covid-19 vaccine could be available for “some” by Christmas but it would be a “colossal mistake” for Brits to relax amid the winter second wave, Jonathan Van-Tam has said. 

England’s deputy chief medical officer said he was “hopeful” a vaccine programme could soon be rolled out, but cautioned it would be the spring before a “horizon” was in sight.

“We have seen a swallow but this is very much not the summer,” he said, at the Downing Street press conference on Monday. 

It came after the announcement from Pfizer and BioNTech that a coronavirus vaccine in trials is more than 90% effective in preventing the disease.

John Bell, who advises the government and is professor or medicine at Oxford University, said on Monday that it was a “major step” in the fight against the virus and he could say “with some confidence” life could return to normal by spring. 

Van-Tam said the news represented a significant moment in the battle against the disease, but that it would be for the independent regulator to clear it for use in the UK.

“This is a very important scientific breakthrough. I am certain of that,” he said.

“I am hopeful because of all that, but not yet certain that we could begin to see some vaccine by Christmas.”

He said age would be “by far and away” the most important factor in determining who should receive the vaccine first.

Using a football metaphor, he said: “So this is like… getting to the end of the playoff final, it’s gone to penalties, the first player goes up and scores goal.

“You haven’t won the cup yet, but what it does is it tells you that the goalkeeper can be beaten.”

But Prof Van-Tam said “we don’t yet know” when life can get back to normal or when coronavirus restrictions can start to be lifted.

“Frankly, we’re in the middle of the second wave, and I don’t see the vaccine making any difference for the wave we are now in,” he said.

“I’m hopeful that it may prevent future waves, but this one we have to battle through to the end without a vaccine.”

Prime minister Boris Johnson echoed what Van-Tam said, adding: 
“We absolutely cannot rely on this news as a solution and the biggest mistake we could make now is to soften our resolve.”

The PM said “scientific cavalry” was on its way, but stressed the need for caution.

“I must stress that these are very, very early days,” he said. 

Johnson said he had talked about the “distant bugle of the scientific cavalry coming over the brow of the hill” with a breakthrough.

“I can tell you that tonight that toot of the bugle is louder, but it’s still some way off, we absolutely cannot rely on this news as a solution,” he said.

“The biggest mistake we could make now would be to slacken our resolve at a critical moment.”