Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant
Phase 2a–b trial in South Africa (n=4387) found the NVX-CoV2373 vaccine was efficacious in preventing Covid-19, with higher vaccine efficacy observed among HIV-negative patients (60.1%) and of 41 sequenced isolates, 38 (92.7%) were the B.1.351 variant.
Source:
New England Journal of Medicine
SPS commentary:
The recombinant SARS-CoV-2 nanoparticle vaccine (NVX-CoV2373, Novavax) is produced by engineering a baculovirus that contains a gene encoding full-length SARS-CoV-2 spike glycoprotein (prototype Wuhan-Hu-1 sequence).
According to an editorial vaccine evaluations against new variants will be more challenging going forward as data from randomized, placebo-controlled clinical trials become less common due to enhanced availability of vaccines. It calls for a global scientific agenda that encompasses extensive genomic surveillance, detailed “correlate of protection” evaluations, and robust postintroduction surveillance and sequencing is necessary to measure the effect of new and current vaccines against SARS-CoV-2 variants. It notes that development and testing of second-generation vaccines (including those that target specific variant strains, multiple strains, and antigens other than spike proteins) are under way. It points out that even though faster production timelines will facilitate the manufacturing of new vaccines, factors such as the operational difficulty of replacing current vaccines with new ones, manufacturing regionally specific vaccines, and adding booster doses of a vaccine must be considered in the risk–benefit context. It concludes that the emergence of variant strains is arguably the greatest threat to control of the Covid-19 pandemic, requiring a coordinated global prevention-and-control plan.