UK continues AstraZeneca vaccine amid questions on trial knowledge
© Reuters. FILE PHOTO: UK Health Secretary Matt Hancock attends a Downing Street press conference during the coronavirus disease (COVID-19) outbreak in London
By Alistair Smout and Karen Lema
LONDON / MANILA (Reuters) – The UK gave AstraZeneca’s (NASDAQ 🙂 COVID-19 vaccine a vote of confidence on Friday as it asked its regulatory agency to evaluate the shot for a rollout after experts raised questions about test data and the company this said can do another study to measure effectiveness.
The UK government has received 100 million doses of the vaccine developed by AstraZeneca and Oxford University, most of it ordered from a gunshot to fight a pandemic that killed more than 1.4 million people worldwide.
The UK drug maker expects 4 million doses to be available in the country by the end of next month, and Health Secretary Matt Hancock is aiming for a rollout to begin before Christmas.
“We have formally asked regulators to evaluate the Oxford / AstraZeneca vaccine, understand the data and determine if it meets strict safety standards,” said Hancock.
“This letter is an important step in getting a vaccine to be used safely as soon as possible.”
The UK Medicines and Health Products Regulatory Authority (MHRA) launched an accelerated “rolling review” of the vaccine earlier this month as data on safety and effectiveness are available.
In the global race to develop vaccines against COVID-19, the candidate is seen by AstraZeneca as one of the best hopes for many developing countries due to its lower price tag and ability to be shipped at normal refrigerator temperatures.
Officials in the Philippines said Friday they would secure 2.6 million AstraZeneca shots – the country’s first supply deal for a COVID-19 vaccine – and were negotiating a possible purchase of an additional 1 million doses.
The announcements came after some scientists expressed doubts about the robustness of the results, which showed that the shot was 90% effective in a subset of subjects who mistakenly received half a dose initially followed by a full dose.
AstraZeneca on Monday released trial data showing that its experimental vaccine prevented an average of 70% of COVID-19 cases in late-stage studies in the UK and Brazil.
While the success rate in the subgroup was 90%, some experts said the relatively small number of participants made the results more difficult to rely on.
AstraZeneca said the half-dose administration had been reviewed and approved by independent data security monitors and the UK regulator, adding that the regulator publicly confirmed that there were “no concerns”.
As with most participants, the success rate of 62% with two doses of the full dose is still above the 50% required by the US regulatory authorities. The European Medicines Agency has announced that it will not set a minimum level of effectiveness.
If a vaccine is 50% effective, it means that an average of 100 of them will not be infected if 100 people who have not been exposed to the virus are immunized with it.
However, CEO Pascal Soriot said Thursday that the drug maker will likely conduct an additional global study to evaluate the effectiveness of its vaccine using the lower dosage.
An Oxford University spokesman said additional data from international studies would help researchers assess the vaccine’s effectiveness in a more diverse population.
Effectiveness figures of the EXPLAINER study:
Pauline Londeix, co-founder of French drug transparency group OT-Med, said the apparent confusion about the trial results was “very problematic for public confidence in vaccines”.
“It largely has to do with the race that drug makers are currently engaging in, which results in them doing their best to present vaccine candidates rather than publishing full protocols and results. It is the opposite of what we believe is required.”
Still, the UK’s leading scientific advisor said the interim results showed the AstraZeneca vaccine was successful.
“The main result is the vaccine effect and that is very exciting,” Patrick Vallance said Thursday during a press conference with Prime Minister Boris Johnson.
Only 2,741 volunteers were in the subgroup of the AstraZeneca-Oxford study that found a 90% effectiveness indicator, a fraction of the tens of thousands in studies that resulted in the over 90% effectiveness data released earlier this month for Pfizer-BioNTech’s and Modern (NASDAQ 🙂 Vaccines.
“Subgroup analyzes in randomized controlled trials are always difficult,” said Paul Hunter, professor of medicine at the University of East Anglia, UK.
“To be confident in the results,” added Hunter, any subgroup analysis with a large number of volunteers should be “sufficiently performing”.
‘NUMBER OF VARIABLES’
AstraZeneca’s shares fell 0.7% to around 1055 GMT. They have fallen about 7% since vaccine data was reported on Monday.
Optimism over vaccines helped the stock hit highs this year, making the drug maker the most valuable UK public company. However, its shares are down over 17% since late July, trailing Unilever (NYSE 🙂 and Shell (LON :).
In contrast to AstraZeneca’s decline this week, Moderna stocks are up 22% since vaccine trial data was released on November 16 and 22 Pfizer (NYSE 🙂 and BioNTech are up 6% and 14%, respectively, since the data was released on November 9th.
A peer-reviewed analysis of the data from the AstraZeneca-Oxford study will be published in The Lancet in the coming weeks.
The US Food and Drug Administration (FDA) has not commented on the results of AstraZeneca’s vaccine study. The European Medicines Agency said Thursday it would “evaluate data on the effectiveness and safety of the vaccine in the coming weeks once it is received from the company”.
Moncef Slaoui, chief scientific advisor to the US government’s Operation Warp Speed vaccination program, has also identified gaps in the data from the intermediate trials.
He said no one in the subgroup who received the initial half-dose was older than 55 years – suggesting that the regime’s effectiveness in older age groups has not been proven.
“There are a number of variables that we need to understand and what role each of them played in making the difference in effectiveness,” Slaoui said in a briefing Tuesday.