The government will “look very carefully” at concerns that the initial effectiveness of the Pfizer-BioNTech coronavirus vaccine is low, said the UK’s leading government scientist.
Israel, which has already given the first dose to about a quarter of its population, warned that the effectiveness could be as low as 33% after the first injection.
However, it has been revealed that it is likely to protect against the most infectious variant of coronavirus that has been identified in the UK and has helped to increase cases.
The low initial effectiveness may have implications for the UK vaccine strategy, which focuses on giving the largest number of people an initial dose before providing the booster vaccine up to 12 weeks later.
To watch: The Pfizer vaccine appears effective against the UK variant
Speaking to Sky News, Sir Patrick Vallance, the government’s chief scientific adviser, said that between the 10th day after the first dose and 21 days later, the studies’ effectiveness was “much closer to 89%”.
However, he cautioned that “when you get into real-world practice, things are rarely as good as clinical trials.”
“It probably won’t be as high in practice, but I don’t think it will be as low as the numbers you just provided,” he told Sky’s Q&A.
“We need to look at this very carefully, we just need to keep measuring and understanding.”
Later on Wednesday, a Downing Street spokesman insisted that the decision to give a second jab after 12 weeks came from available data, which showed that the Pfizer-BioNTech vaccine is 89% effective in protecting against COVID-19 among 15 and 21 days after the first dose.
“But again, I would like to point out what medical experts and scientific advisors said earlier about the fact that once you have received the first dose, it takes some time for your body to create immunity,” said the spokesman.
“You do not have immunity immediately after taking the first dose, but again, we explain why we are administering the dosages the way we do, and that is to protect as many people as possible as quickly as possible.”
‘Insufficient’ data to say UK vaccine policy is wrong
Reuters reports that Israel is working with Pfizer to provide data on the vaccine.
Professor Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, said that Israel’s reports are “insufficient to provide any evidence that the UK’s current policy on postponing the second dose of vaccines is somehow incorrect ”.
“It is unwise to compare the effectiveness derived from such an observational study, which is subject to many biases, with the effectiveness derived from randomized trials,” he said.
The professor added that more robust data must be collected before a change in policy on how vaccine doses are given.
Vaccines ‘don’t do enough hard work’
Sir Patrick warned that coronavirus cases need to decrease before the government thinks about easing the blockade.
He said the vaccines are still not doing enough “heavy lifting” to give the government reasons to lift the restrictions, but he said there is “light at the end of the tunnel”.
Officials hope to give the most vulnerable to COVID-19 – about 15 million people – a dose of vaccine by February 15, and there are reports that the government wants to ease restrictions by Easter.
More than 4.2 million first doses were given, and 450,000 second jabs were delivered.
“The advice at the moment is that vaccines will not do the heavy lifting for us at the moment, anywhere near that,” said Sir Patrick.
“These are, I am afraid, the restrictive measures under which we all live and continue with them.
“The numbers are nowhere near where they need to be at the moment, they need to decrease much more – we need to make sure that we continue with them.
“You are going to walk in the park or something, life seems normal; you will walk in a hospital, if you work in a hospital, you will see that life doesn’t look normal.
“This is a really difficult and dangerous situation that we are in, and we need to reduce the numbers, so I don’t see a release of these measures as a sensible thing to do in the short term.”
Watch: What is COVID Long?