Faculty of Pharmaceutical Medicine statement on ongoing US trial of AZD1222

The Faculty of Pharmaceutical Medicine (FPM) welcomes the announcement from AstraZeneca of the primary analysis of the ongoing US trial of AZD1222. The point estimate of efficacy (76%) announced, while lower than the 79% point estimate reported on 22.3.21, is within an expected range of variability given the number of affected patients, sample size and the changed duration of observation within the study, during which time the numbers of cases rose from 141 to 190. It is noted that the point estimate of efficacy in the 20% of the population over 65 has, in the same time, increased from 80 to 85%. The point estimates of efficacy in vaccine trials are expected to vary, based on the ‘attack rate’ in the placebo group, the duration of follow up post vaccine and, potentially, differences in sensitivity of the circulating viral strains over time.

The rush to provide information can occasionally lead to a ‘publication by press release’ approach, with potentially premature release of data, which is sometimes not easily interpretable. FPM strongly supports the rapid publication of all relevant data in a peer-reviewed publication, so that research results can be critically appraised and interpreted. This will help to support the medical community to understand any potential impact on current policy so that they, in turn, can appropriately advise and support their patients.