By Kingsley I. Ilechukwu

With the European Medicines Agency (EMA) announcing that it will also initiate a rolling review of the COVID-19 vaccine developed by Pfizer and BioNTech besides just AstraZeneca’s asset, Pharma Writer for the Investigative News team at GlobalData, Reynald Castañeda offers his view:

“After interviewing ten experts, there is clearly a split in terms of whether AstraZeneca’s COVID-19 vaccine AZD1222 trials restarted too quickly on the heels of news reports of a trial volunteer having transverse myelitis. With regards to the other vaccine frontrunners, Pfizer and BioNTech’s trial design may have an edge in reporting data earlier – yet Moderna’s may offer data granularity to help decisions as to who should be prioritized for a jab.

“With regards to AstraZeneca’s ongoing trial pause in the US, while some experts agreed with the FDA that more in-depth analysis is needed to conclude these events are truly independent of the vaccine, others noted these cases are unprecedented with the vaccine’s adenovirus vector and so could be due to chance.

“The FDA has broadened its investigations and still has the US trial on hold. Yet, on 1 October, the EMA announced it was starting a rolling review of AZD1222, and after the company confirming on 9 September it had paused its global AZD1222 investigations, all ex-US trials have now restarted, including in Brazil, Japan and South Africa, as well as the UK, where two neurological events occurred in two separate trials.

“However, several experts noted there should be more scrutiny over whether the process has had enough time to properly evaluate if more neurological events could occur later in the trial or in the general population. The first event that triggered an AstraZeneca trial pause was multiple sclerosis, which was concluded as not caused by the vaccine, yet is in the same neurological disease ballpark as transverse myelitis. But other experts noted the vaccine’s cost-benefit ratio would deserve more scrutiny only if there were more of the same events in the trials.

In general, interviewed experts cautioned that any COVID-19 vaccine receiving an Emergency Use Authorization (EUA) from the FDA based on interim analysis data is unlikely to offer detailed information about which subpopulations the authorized vaccine is best suited for.

“Pfizer and BioNTech’s late-phase BNT162b2 trial is designed to report interim data earlier than others in the race and has the potential for a broader label than Moderna’s mRNA-1273 vaccine, which is also based on mRNA technology like BNT162b2. Yet, Pfizer and BioNTech’s early results could leave vaccinators unclear about which patient group would be best suited to use the vaccine.

“Such detail is crucial considering initial vaccine supply is expected to be limited and so would need to be prioritized for distribution. Prioritization discussions is recently in front of mind in the UK, with the head of the UK’s vaccine task force noting that less than half of the UK population is to receive a COVID-19 vaccine.”