August 6, 2021 -- Novavax announced preliminary data indicating that a single booster dose of the company's recombinant nanoparticle protein-based COVID-19 vaccine drew a 4.6-fold increase in functional antibody titers.
The booster dose had a sixfold increase in cross-reactive functional antibodies to the coronavirus delta variant compared to the primary vaccination series, the company said. Analysis of sera from the primary vaccination series also showed cross-reactive functional antibodies to alpha, beta, and delta variants, all of which increased six- to tenfold with the booster dose.
The results come from an ongoing phase II study in the U.S. and Australia in which participants in one cohort received a 5-μg booster dose 189 days after the initial two-dose vaccine regimen to examine the functional immune response. The company also noted that the booster dose was "generally well tolerated."