Covid-19 vaccines

Pfizer/BioNTech presented the initial results for their mRNA based BNT162b2 vaccine, which showed that it was 90% effective in preventing covid-19.  The vaccine was tested on 43,538 participants and, so far, there have been 94 confirmed cases. They will submit to the US Food and Drug Administration (FDA) for approval when the safety profile has reached a pre-determined milestone. In the meantime, Pfizer has continued to market the vaccine.

Secondly, the Data Safety Monitoring Board, appointed by the National Institutes of Health (NIH) for the phase III study of the MODERNA mRNA-1273 vaccine candidate against covid-19, confirmed its trial met the statistical criteria pre-specified in the study protocol, with a vaccine efficacy of 94.5%.

Thirdly, the University of Oxford and AstraZeneca, announced that their adenovirus-based vaccine ChAdOx1 nCoV-2019 was safe and also, in the preliminary findings of a peer-reviewed phase II/III trial, as triggering a seemingly encouraging immune response in older age groups included in the trial.  In a subsequent press release, they reported that in the phase III trial of about 20,000 participants, the vaccine was around 70% efficacious. This week it has also transpired that some of the participants were, in error, given a first dose which was half of what was intended. These participants were all under the age of 55. Doubts have now been raised about how Oxford and Astra Zeneca have handled the release of their preliminary results, given the dosing error and what that could mean for the efficacy of the vaccine.

All these data for the different vaccines are potentially very promising, but none of the phase III trials have been published in peer reviewed journals or analysed by age group, gender and case description (asymptomatic, mild, severe), virus transmissibility after immunisation, or duration of protection.

As public health professionals, we believe that the results of clinical trials, whether interim or final, should be subject to an appropriate systematic process, and then published in peer-reviewed professional journals. Reporting the covid-19 vaccine trial results in press releases before publication in journals is neither good scientific practice nor does it help to build public trust in vaccines. If trial data for covid-19 candidate vaccines are prematurely announced, this may threaten the integrity and credibility of the trials. This could distort what should be a rigorous peer review process. We believe that data and conclusions should not be released as credible before the scientific community can judge the validity of those claims by assessing a complete account of what was done.

The process of reporting on the clinical trials and the concurrent marketing of the covid-19 vaccines also raises concerns about the basis on which the many candidate vaccines at advanced stages of development can be assessed. Since companies are asking governments to place orders at an early stage, this raises a question about the minimum amount of data that companies should release publicly during the marketing process.