Formica N, Mallory R, Albert G, et al. - The findings of the study confirmed that the 2-dose regimen of 5-μg NVX-CoV2373 is highly immunogenic and well-tolerated in younger adults, as found in phase 1. In addition, the 5 μg 2-dose regimen was well tolerated in older adults and demonstrated sufficient immunogenicity to support its use in late-phase efficacy studies.

• Candidates (n = 1,288) were randomly assigned to 1 or 2 intramuscular doses of 5-μg or 25-μg NVX-CoV2373 or placebo (aged 18 to 59 and 60 to 84 years).

• After the first and second vaccinations with NVX-CoV2373, reactogenicity was predominantly mild to moderate in severity and of short duration (median < 3 days), with higher frequencies and intensity after the second vaccination and with the higher dose.

• In older participants, reactogenicity occurred less frequently and with less intensity.

• The 5-g NVX-CoV2373 2-dose regimen was found to be immunogenic and well-tolerated in both younger and older adults.