Article
作者: Patel, Nita ; Deshmukh, Sachin ; Cho, Iksung ; Plested, Joyce S. ; Marcheschi, Alex ; Cloney-Clark, Shane ; Kalkeri, Raj ; Bennett, Chijioke ; Mallory, Raburn M. ; Pardey, Toni McCallum ; Bloch, Mark ; Glenn, Gregory M. ; Cumming, Oscar ; Smith, Gale ; Woo, Wayne ; Griffin, Paul ; Swan, Jennifer ; Mohan, Rahul ; Zhu, Mingzhu ; Neville, A. Munro ; Rivers, E. Joy ; Walker, Robert ; Arya, Mark ; Buchanan, Agi ; Cheung, King
Background:Mutations present in emerging SARS-CoV-2 variants permit evasion of neutralization with prototype vaccines. A novel Omicron BA.1 subvariant–specific vaccine (NVX-CoV2515) was tested alone or as a bivalent preparation with the prototype vaccine (NVX-CoV2373) to assess antibody responses to SARS-CoV-2.
Methods:Participants aged 18 to 64 years immunized with 3 doses of prototype mRNA vaccines were randomized 1:1:1 to receive a single dose of NVX-CoV2515, NVX-CoV2373, or the bivalent mixture in a phase 3 study investigating heterologous boosting with SARS-CoV-2 recombinant spike protein vaccines. Immunogenicity was measured 14 and 28 days after vaccination for the SARS-CoV-2 Omicron BA.1 sublineage and ancestral strain. Safety profiles of vaccines were assessed.
Results:Of participants who received trial vaccine (N = 829), those administered NVX-CoV2515 (n = 286) demonstrated a superior neutralizing antibody response to BA.1 vs NVX-CoV2373 (n = 274) at day 14 (geometric mean titer ratio, 1.6; 95% CI, 1.33–2.03). Seroresponse rates were 73.4% (91/124; 95% CI, 64.7–80.9) for NVX-CoV2515 vs 50.9% (59/116; 95% CI, 41.4–60.3) for NVX-CoV2373. All formulations were similarly well tolerated.
Conclusions:NVX-CoV2515 elicited a superior neutralizing antibody response against the Omicron BA.1 subvariant as compared with NVX-CoV2373 when administered as a fourth dose. Safety data were consistent with the established safety profile of NVX-CoV2373.
Clinical Trials Registration:ClinicalTrials.gov (NCT05372588).