LONDON / MANILA: Britain asked its regulator on Friday to evaluate AstraZeneca’s Covid-19 vaccine for a possible launch, while the Philippines and Thailand secured millions of doses, giving the injection a vote of confidence after it the experts raised questions about test data.
The UK government, which has secured 100 million doses of the vaccine developed by AstraZeneca and the University of Oxford, has aimed for the rollout to begin before Christmas.
“We have formally asked the regulator to evaluate the Oxford / AstraZeneca vaccine, understand the data and determine if it meets rigorous safety standards,” said British Health Secretary Matt Hancock.
“This letter is an important step toward deploying a vaccine as quickly and safely as possible.”
In the global race to develop vaccines against Covid-19, the AstraZeneca candidate is considered to offer one of the best hopes for many developing countries due to its cheaper price and its ability to be transported at normal refrigerator temperatures.
The Thai government signed an agreement on Friday to purchase 26 million doses of the vaccine to fight the pandemic, which has killed more than 1.4 million people worldwide. Officials in the Philippines said they would get 2.6 million injections and were negotiating a possible purchase of 1 million more doses.
The announcements came after some scientists raised doubts about the robustness of the results showing that the injection was 90% effective in a subset of trial participants who mistakenly initially received a half dose followed by a full dose.
AstraZeneca CEO Pascal Soriot It said Thursday that the drugmaker is likely to conduct an additional global test to assess the efficacy of its vaccine using the lowest dose.
The company had released test data on Monday showing that its experimental vaccine prevented an average of 70% of Covid-19 cases in late-stage trials in Britain and Brazil.
While the success rate was 90% in the subgroup, some experts said that the relatively small number of participants made it difficult to trust the findings.
AstraZeneca said the administration of half the dose had been reviewed and approved by independent data safety monitors and the UK regulator, adding that the regulator publicly confirmed that “there were no concerns”.
‘PROBLEMATIC’ CONFUSION
When the full dose was administered twice, as was the case with most trial participants, the success rate was 62%, still above the 50% required by US regulators. The European drug regulator has said that it will not establish a minimum level of effectiveness.
If a vaccine is 50% effective, it means that if 100 people who have not been exposed to the virus are immunized with the injection, 50 of them would not be infected, on average.
A spokesman for the University of Oxford said that additional data from international trials would help researchers assess the vaccine’s efficacy among a more diverse population.
EXPLAINER Trial Efficacy Numbers:
But Pauline Londeix, co-founder of the French drug transparency group OT-Med, said the apparent confusion over the trial results was “very problematic for public confidence in vaccines.”
“It has to do largely with the race drug manufacturers are involved in today, leading them to present vaccine candidates in the best possible light and not release full protocols and results. It is the opposite of what is needed in our opinion. ”
However, Britain’s chief scientific adviser said interim results showed the AstraZeneca vaccine to be successful.
“The main result is that the vaccine works and that is very exciting,” Patrick Vallance said Thursday during a news conference with Prime Minister Boris Johnson.
AstraZeneca expects 4 million doses to be available in Britain by the end of December. Britain’s Medicines and Health Products Regulatory Agency (MHRA) launched an accelerated “rolling review” of the vaccine earlier this month as data on safety and efficacy arrive.
‘A NUMBER OF VARIABLES’
The subgroup of the trial that gave the 90% efficacy reading was comprised of 2,741 volunteers, a fraction of the tens of thousands in trials that resulted in efficacy data of greater than 90% published earlier this month for vaccines from Pfizer-BioNTech and Moderna.
“Subgroup analyzes in randomized controlled trials are always fraught with difficulties,” said Paul Hunter, professor of medicine at the University of East Anglia.
“To have faith in the results,” Hunter added, any subgroup analysis has a large number of volunteers.
Shares in AstraZeneca fell 0.9% around 1310 GMT. They have fallen about 7% since the vaccine data was reported Monday.
Vaccine optimism helped propel stocks to record highs this year, making the drugmaker the most valuable UK listed company, but its shares have lost more than 17% since late July and it has lagged behind Unilever and Shell. .
Moderna’s shares have risen 22% since it released its test data on November 16, while Pfizer and BioNTech are up 6% and 14% respectively since they released the data on November 9.
A peer-reviewed analysis of the data from the AstraZeneca-Oxford trial will be published in The Lancet in the coming weeks.
The US Food and Drug Administration (FDA) has not commented on the trial results. The European Medicines Agency said on Thursday it will “evaluate the data on the efficacy and safety of the vaccine in the coming weeks.”
Moncef Slaoui, scientific advisor to the US government’s Operation Warp Speed vaccine program, noted that no one in the subgroup that received half the initial dose was over 55 years old, suggesting that the efficacy of the regimen in older people it was not proven.
“There are a number of variables that we need to understand and what the role of each has been in making the difference in efficacy,” Slaoui said in a briefing on Tuesday.
On video: Covid-19: Britain to continue firing AstraZeneca amid trial questions
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