Canada-based researchers have urged governments to delay administering the second dose of Pfizer/BioNTech’s Covid-19 vaccine – showing that the jab offered nearly 93 per cent efficacy after the first dose in a big boost for Britain’s controversial vaccine strategy.
Published in the New England Journal of Medicine, Danuta Skowronski and Gaston De Serres said their findings were based on documents submitted by Pfizer to the US Food and Drug Administration.
The high efficacy figure of 92.6 per cent after one dose of the Pfizer jab – which was the first to be approved and rolled out in the UK in December – is similar to the reported 92.1 per cent first-dose efficacy of the Moderna vaccine, which uses similar technology.
While the researchers cautioned that there may be uncertainty about how long protection lasts after a single dose, they added that there was “little added benefit in the short term” of scheduling the second dose a month after the first, as the manufacturer recommended.
“Given the current vaccine shortage, postponement of the second dose is a matter of national security that, if ignored, will certainly result in thousands of COVID-19–related hospitalisations and deaths this winter in the United States,” the authors cautioned.
In response, Pfizer said that any decision to use a different dosing regimen resided with health authorities.
“We at Pfizer believe that it is critical for health authorities to conduct surveillance on implemented alternative dosing schedules to ensure that vaccines provide the maximum possible protection,” the company added in a statement.
Authorities in Britain said the the data supported its decision to move to a. 12-week dosing schedule for the Pfizer jab. The UK has already vaccinated more than 15 million people in the four categories identified as being most vulnerable to severe illness or death from Covid-19.
Boris Johnson is awaiting new data on the impact of vaccines on coronavirus after stressing he will take a “cautious and prudent approach” to easing England’s third national lockdown.
The prime minister is understood to be expecting evidence on the impact of the UK’s jabs programme on hospital admissions and deaths by the end of Friday, ahead of setting out his “road map” next week.
But it was unclear whether the early data would include the impact on transmission, with the results of two key Public Health England studies potentially not ready until next month.
Meanwhile, major research showed lockdown measures were significantly driving down infection levels across the nation, but that they remained high and at similar levels to those observed in late September.
Imperial College London’s React study, which tested more than 85,000 people in England between February 4 and 13, suggested infections had dropped to just one in 200 people.
The study suggested infections were halving every 15 days, and the R number – which expresses how many people the average infected individual spreads the virus to – is at 0.72.
But, with the number of Covid-19 patients in hospitals remaining higher than during the first wave in April, experts called for caution in easing restrictions.
Steven Riley, Imperial’s professor of infectious disease dynamics, said that “because prevalence is high, there essentially isn’t a lot of headroom – there isn’t a lot of leeway”.