AstraZeneca PLC (LON:AZN) said it is mulling undertaking a new trial for the coronavirus (COVID-19) vaccine developed with Oxford University after the results announced earlier this week sparked criticism.
Chief executive Pascal Soriot said the pharma giant would look to confirm the 90% efficacy rate the candidate showed in the questioned portion of the trials.
The jab showed an average efficacy of 70%, with the trial generating a 62% success rate when volunteers were given two full doses at least one month apart, but the chances of being protected from the virus rose to 90% when a half dose was administered followed a month later by a full dose.
However, it was revealed that in the trial showing 90% efficacy all participants were younger than 55, meaning they were less at risk from experiencing severe symptoms.
The FTSE 100-listed company came under fire because this lower dosing was a result of a manufacturing error and it did not disclose these facts, causing transparency concerns.
“Now that we’ve found what looks like a better efficacy we have to validate this, so we need to do an additional study,” Soriot told Bloomberg.
He said it is likely to be another international study, “but this one could be faster because we know the efficacy is high so we need a smaller number of patients”.
The UK government, which has pre-ordered 100mln doses of the vaccine, has asked the medicines regulator to analyse whether the Oxford vaccine can get temporary authorisation, though it is still subject to the European authorities approval until Brexit takes place in January.
As for the US, members of the scientific community have said the Food and Drug Administration is unlikely to issue approval with the current data, especially since the trials didn’t take place in the country.
“The question for us was, will we need the US data to get approval in the US or can we get approval in the US with international data, and it was never clear,” said Soriot. “Now with those results it’s more likely that we will need the US data.”
Analysts at Citigroup said they believe the negative sentiment over the comparative efficacy of the Oxford vaccine versus the mRNA vaccines from Pfizer and Moderna, and dosing subgroups, will be reduced once the phase III results are published in the Lancet, as expected this weekend.
“We anticipate rapid licensing of the vaccine and roll out in the UK followed by EU and less developed countries,” the analysts added.
Shares dipped 1% to 7,695p on Friday morning.