Efficacy and Safety of NVX-CoV2373 in Adults in the United States and Mexico

Abstract

BACKGROUND Vaccination using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein antigen has been effective in the prevention of coronavirus disease 2019 (Covid-19). NVX-CoV2373 is an adjuvanted, recombinant S protein nanoparticle vaccine that demonstrated clinical efficacy for prevention of Covid-19 in phase 2b/3 trials in the United Kingdom and South Africa. METHODS This phase 3, randomized, observer-blinded, placebo-controlled trial evaluated the efficacy and safety of NVX-CoV2373 in adults ≥18 years of age in the United States and Mexico during the first quarter of 2021. Participants were randomized in a 2:1 ratio to receive two doses of NVX-CoV2373 or placebo 21 days apart. The primary end point was vaccine efficacy (VE) against reverse transcriptase-polymerase chain reaction-confirmed Covid-19 in SARS-CoV-2-naive participants ≥7 days after the second dose administration. RESULTS Of the 29,949 participants randomized between December 27, 2020, and February 18, 2021, 29,582 (median age: 47 years, 12.6% ≥65 years) received ≥1 dose: 19,714 received vaccine and 9868 placebo. In the per-protocol population, there were 77 Covid-19 cases; 14 among vaccine and 63 among placebo recipients (VE: 90.4%, 95% confidence interval [CI] 82.9 to 94.6, P<0.001). All moderate-to-severe cases occurred in placebo recipients, yielding VE of 100% (95% CI 87.0 to 100). Most sequenced viral genomes (48/61, 78.7%) were variants of concern (VOC) or interest (VOI), mainly represented by variant alpha/B.1.1.7 (31/35, 88.6% VOC identified). VE against any VOC/VOI was 92.6% (95% CI 83.6 to 96.7). Reactogenicity was mostly mild-to-moderate and transient, but more frequent in NVX-CoV2373 recipients and after the second dose. Serious adverse events were rare and evenly distributed between treatments. CONCLUSIONS NVX-CoV2373 was well tolerated and demonstrated a high overall VE (>90%) for prevention of Covid-19, with most cases due to variant strains. (Funded by the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health; PREVENT-19 ClinicalTrials.gov number, NCT04611802.)

Effectiveness and durability of the mRNA vaccine-induced SARS-CoV-2-specific humoral and cellular immunity in severe asthma patients on biological therapy

“…The COVID-19 vaccine has been shown to elicit SARS-CoV-2-specific immunity in multiple studies, and this capability relates to both humoral and cellular immunity (2)(3)(4)(5)(6).…”

“…Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the COVID-19 pandemic, and the effort in fighting the disease largely relies on prophylactic vaccination (1). Currently used COVID-19 vaccines provide a high level of protection against SARS-CoV-2 infection and severe forms of COVID-19 (2)(3)(4)(5)(6). The COVID-19 vaccines induce a strong humoral and cellular response in a healthy population (7).…”

Adverse effects of vaccinations and potential therapies against COVID-19

“…Problem zapewne nie jest tak istotny, jeśli ktoś przyjmuje drugą czy trzecią dawkę i zakazi się w punkcie szczepień. W ostatnim czasie testy bezpieczeństwa przeszła szczepionka antygenowa Novavax, w przypadku której stężenie SPIKE we krwi jest wyższe, podważając wyraźnie zasadność obaw o zarówno ADE polegające na tworzeniu kompleksów antygen-przeciwciało, jak i ADE polegające na ułatwieniu przez przeciwciała infekcji wirusowej [25,26].…”

“…testach antygenowych białka SPIKE po szczepieniu, a oczywiście udaje się z wysokim prawdopodobieństwem w trakcie infekcji. Testy bezpieczeństwa szczepionki antygenowej Novavax, w przypadku której stężenie SPIKE we krwi jest wyższe, podważają wyraźnie zasadność tych obaw [25,26]. W trakcie badań klinicznych NVX-CoV2373 (Novavax) nie wykryto zapaleń mięśnia sercowego, zakrzepicy czy trombocytopenii.…”

Criteria for judging the immune markers of COVID‐19 disease vaccines

“…1 Multiple types of vaccines showed varied vaccine efficacies (VEs) ranging from 50% to 95% against symptomatic COVID-19 infections in phase III clinical studies; seven of them have been approved for marketing or emergency use by WHO. [2][3][4][5][6][7][8][9][10][11][12][13][14] Approved vaccines are mainly classified into four types: inactivated virus vaccines like CoronaVac, BIBP-CorV, and BBV-152; adenoviral vector vaccines like Ad26.COIV2.S; protein subunit vaccines like ChAdOx1-S; and mRNA encoding vital proteins like mRNA-1273 and BNT162b2. According to the characteristics of these vaccines, the safety and efficacy might be different.…”