1. Efficacy of the NVX-CoV2373 Covid-19 Vaccine Against the B.1.351 Variant
- Author
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Leon Fouche, Greg Glenn, Susan Neal, Chijioke Bennett, Anthonet Koen, Tulio de Oliveira, Andreana Robertson, Asha Thombrayil, Natasha Lalloo, Lee Fairlie, Gary Albert, Iksung Cho, Mingzhu Zhu, Aylin Oommen-Jose, Zaheer Hoosain, Lou Fries, Sherika Hanley, Vicky L Baillie, Moherndran Archary, As'Ad E. Bhorat, Michele Tameris, Aliasgar Esmail, Pieter Louis Vollgraaff, Shabir A. Madhi, Filip Dubovsky, Sutika Bhikha, Friedrich G. Petrick, Annah Pitsi, Sharne Foulkes, Nazira Carrim-Ganey, Keertan Dheda, Ameena Ebrahim Goga, Gertruida Kruger, Angelique Kany Kany Luabeya, Joyce S. Plested, Dhayendre Moodley, Emmanuel Faust, Nishanta Singh, Q E Bhorat, Coert Grobbelaar, Shane Cloney-Clark, Umesh G. Lalloo, Johan Lombaard, Vivek Shinde, Mduduzi Masilela, Khatija Ahmed, Gabriella Benade, Cheryl Louw, and Rosie Mngqibisa
- Subjects
Adult ,2019-20 coronavirus outbreak ,COVID-19 Vaccines ,Coronavirus disease 2019 (COVID-19) ,Adolescent ,viruses ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,030204 cardiovascular system & hematology ,Article ,COVID-19 Serological Testing ,03 medical and health sciences ,South Africa ,Young Adult ,0302 clinical medicine ,Immunogenicity, Vaccine ,Double-Blind Method ,HIV Seronegativity ,Pandemic ,HIV Seropositivity ,Medicine ,Humans ,030212 general & internal medicine ,Adverse effect ,Aged ,Aged, 80 and over ,biology ,business.industry ,SARS-CoV-2 ,Immunogenicity ,virus diseases ,COVID-19 ,General Medicine ,Middle Aged ,Virology ,Antibodies, Neutralizing ,Multicenter study ,biology.protein ,Antibody ,business - Abstract
BACKGROUND: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants threatens progress toward control of the coronavirus disease 2019 (Covid-19) pandemic. In a phase 1-2 trial involving healthy adults, the NVX-CoV2373 nanoparticle vaccine had an acceptable safety profile and was associated with strong neutralizing-antibody and antigen-specific polyfunctional CD4+ T-cell responses. Evaluation of vaccine efficacy was needed in a setting of ongoing SARS-CoV-2 transmission. METHODS: In this phase 2a-b trial in South Africa, we randomly assigned human immunodeficiency virus (HIV)-negative adults between the ages of 18 and 84 years or medically stable HIV-positive participants between the ages of 18 and 64 years in a 1:1 ratio to receive two doses of either the NVX-CoV2373 vaccine (5 μg of recombinant spike protein with 50 μg of Matrix-M1 adjuvant) or placebo. The primary end points were safety and vaccine efficacy against laboratory-confirmed symptomatic Covid-19 at 7 days or more after the second dose among participants without previous SARS-CoV-2 infection. RESULTS: Of 6324 participants who underwent screening, 4387 received at least one injection of vaccine or placebo. Approximately 30% of the participants were seropositive for SARS-CoV-2 at baseline. Among 2684 baseline seronegative participants (94% HIV-negative and 6% HIV-positive), predominantly mild-to-moderate Covid-19 developed in 15 participants in the vaccine group and in 29 in the placebo group (vaccine efficacy, 49.4%; 95% confidence interval [CI], 6.1 to 72.8). Vaccine efficacy among HIV-negative participants was 60.1% (95% CI, 19.9 to 80.1). Of 41 sequenced isolates, 38 (92.7%) were the B.1.351 variant. Post hoc vaccine efficacy against B.1.351 was 51.0% (95% CI, -0.6 to 76.2) among the HIV-negative participants. Preliminary local and systemic reactogenicity events were more common in the vaccine group; serious adverse events were rare in both groups. CONCLUSIONS: The NVX-CoV2373 vaccine was efficacious in preventing Covid-19, with higher vaccine efficacy observed among HIV-negative participants. Most infections were caused by the B.1.351 variant. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT04533399.).
- Published
- 2021