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.
In actual fact, the jab showed an average efficacy of 70% but when volunteers were given a half dose followed by a full dose at least one month apart, the chances of being protected from the virus were 90%. This rate fell to 62% when administered as two full doses at least one month apart.
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 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.”
Shares dipped 1% to 7,695p on Friday morning.