Pfizer follows Moderna’s suit in releasing Covid-19 vaccine study protocol

Protocols – essentially the blueprints for clinical trials – are typically kept under wraps until studies are complete, but Pfizer and Moderna have made the ones for their SARS-CoV-2 trials public in a transparency push.

Shortly after one of the leading companies developing a vaccine against the virus that causes Covid-19 took the unusual step of releasing its Phase III clinical trial protocol online, another drugmaker with a vaccine development program already in the late stages has done the same.

New York-based Pfizer publicly released the 137-page protocol of its Phase I/II/III trial of the BNT162 vaccine program, which the company is developing under a partnership with Mainz, Germany-based BioNTech. The move closely follows a decision by Cambridge, Massachusetts-based Moderna to release its protocol for the Phase III trial of mRNA-1273.


A protocol is essentially the blueprint for a clinical trial and contains granular details on things like patient selection, statistical analysis and measurement of outcomes and adverse events. Drugmakers typically keep them closely under wraps until a study has been completed.

However, Moderna released its 135-page protocol Thursday as part of its R&D day as a way of demonstrating transparency in its study. The company also provided an update on the enrollment of the study, stating that as of Wednesday, it had enrolled about 84% of the 30,000 participants it is slated to recruit, while one-third of those participants – all healthy volunteers – have received both the primary and booster shots of the vaccine. The vaccine is administered in two doses, including one given 29 days after the first shot.

In a note to investors Thursday, Morgan Stanley analyst pointed to a number of highlights in the Moderna protocol that he thought would help address some frequent questions from investors. These included the study population used for primary efficacy analysis, who must have no known history of infection with SARS-CoV-2; and the fact that randomization is stratified by age and health risk with three identified health strata, namely those aged 65 or older, those younger than 65 but with increased risk of Covid-19 complications, and those under 65 who are not at risk, with at least 25% of those enrolled – but not more than 40% – having to be in the elderly or high-risk stratum. The methods for estimating efficacy – hazard ratio using a Cox porportional hazard regression model and cases being counted starting 14 days after the second dose – also differ from the bank’s analysis based on relative risk, he noted.

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