While Phase 3 clinical data concerning the COVID-19 vaccines from Pfizer (NYSE:PFE) and Moderna (NSDQ:MRNA) vaccine candidates are promising, it is not yet clear that they provide long-lasting immunity.
Data published in the New England Journal of Medicine, however, indicates that the Moderna mRNA-1273 yielded elevated antibodies in 34 Phase 1 clinical trial participants 90 days after they received the second vaccine dose. The two doses were administered 28 days apart.
While the binding and neutralizing antibodies dipped slightly over the 90 days, their antibody levels were higher than the levels in 41 non-vaccinated controls who were infected with the novel coronavirus. The median time after COVID-19 diagnosis that antibody levels were assessed in those controls was 34 days.
The patients in the Phase 1 trial received a 100-μg dose of mRNA-1273, which is the same amount administered in the Phase 3 study.
Vaccine expert Paul Offit recently mused that the immunity from COVID-19 vaccines likely lasts years but not decades.
Immunity to other coronaviruses lasts roughly 12–18 months.
A Lancet paper concluded that the durability of COVID-19 vaccines’ protections would be unclear for “a number of years.”
Filed Under: clinical trials, Drug Discovery