Comirnaty’s six-month data is a testament to the vaccine’s durability, which is likely to be maintained up to at least 12 months following the initial two-dose regimen, said Phase III Comirnaty investigator Dr Stephen Thomas, chief, Infectious Disease Division, Upstate Medical University, Syracuse, New York. The six-month data from the Phase III portion of the Phase I/II/III trial showed a 3.7-point drop to 91.3% efficacy against symptomatic disease based on 850 confirmed infections in the placebo arm and 77 in the Comirnaty arm, according to a 1 April media release.
In general, a vaccine that triggers a durable response for the first six months typically has longer-term durability, Thomas added. And so, despite mRNA vaccines being a new technology, it is unlikely that Comirnaty’s efficacy will drop below 50% protection in the next six months, he noted. Regulatory agencies’ passing grade for Emergency Use Authorizations (EUAs) is 50%.