Alliance for Pandemic Preparedness

May 6, 2021

Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant



Keywords (Tags):

  • Results from a multicenter, randomized, observer-blinded, placebo-controlled phase 2a-b trial in South Africa of the NVX-CoV2373 (Novavax) nanoparticle vaccine indicated a 49% vaccine efficacy against SARS-CoV-2 infection among 2,684 participants. 94% of participants were HIV-negative and 6% were people living with HIV. After 1:1 vaccine to placebo randomization, 15 participants in the vaccine arm and 29 participants in the placebo arm developed predominantly mild to moderate COVID-19. Efficacy in HIV-negative participants was 60% and did not differ by presence of antibodies at baseline.  Among individuals who developed COVID-19 and had a sequenced viral isolate, 38 (93%) of 41 were the B.1.351 variant and post-hoc vaccine efficacy against B.1.351 was 51% among the HIV-negative participants.
  • Notably, among placebo recipients the incidence of symptomatic COVID-19 was similar in those with and without evidence of anti-SARS-CoV-2 antibodies at baseline during the first 2 months of follow-up (5.3% vs 5.2%).  The authors conclude that this suggests prior infection provided no protection against developing clinical disease when infected with the B.1.351 variant. [EDITORIAL NOTE: An earlier version of this manuscript was summarized as a pre-print in the report on March 3, 2021].

Shinde et al. (May 5, 2021). Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant. New England Journal of Medicine.