AstraZeneca Covid-19 vaccine clinical trial readout may arrive in mid-November, Jefferies says

Analysts at Jefferies estimated that an initial read-out on AstraZeneca and Oxford University's ongoing late-stage trial of its Covid-19 vaccine might ready towards the middle of November.

The broker arrived at that conclusion using what it described as a "back-of-the-envelope statistical analysis", under the assumption that the vaccine would prove 60% effective.

They also pointed out the possibility that the vaccine, AZD 1222, could prove better at moderating symptoms rather than preventing them altogether, which would make it harder to obtain a successful readout.

According to the US Food and Drug Administration, efficacy of 50% or greater was necessary in order for it to grant so-called Emergency Use Authorisation for ASD 1222.

If the vaccine's efficacy was closer to 50%, then the headline efficacy data could be available in December.

Nevertheless, they cautioned that they had also had to make various other assumptions, because they did not have access to AstraZeneca's detailed statistical analysis plan.

Hence, they had used what had been disclosed for the US clinical trial of the same drug as a starting point.

Another assumption was that the rate of infections in the UK would continue to rise, with the seven-day moving average having already done so, from roughly 3,700 cases per day in mid-September to above 16,000 at present.

"We see a risk the vaccine ameloriates infections and the risk of transmission but perhaps has less effect on initial presentation of symptoms, suggesting a benefit to society but raising the bar for a successful readout."