Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months

Abstract

Background BNT162b2 is a lipid nanoparticle–formulated, nucleoside-modified RNA vaccine encoding a prefusion-stabilized, membrane-anchored severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) full-length spike protein. BNT162b2 is highly efficacious against coronavirus disease 2019 (Covid-19) and is currently approved, conditionally approved, or authorized for emergency use worldwide. At the time of initial authorization, data beyond 2 months after vaccination were unavailable. Methods In an ongoing, placebo-controlled, observer-blinded, multinational, pivotal efficacy trial, we randomly assigned 44,165 participants 16 years of age or older and 2264 participants 12 to 15 years of age to receive two 30-μg doses, at 21 days apart, of BNT162b2 or placebo. The trial end points were vaccine efficacy against laboratory-confirmed Covid-19 and safety, which were both evaluated through 6 months after vaccination. Results BNT162b2 continued to be safe and have an acceptable adverse-event profile. Few participants had adverse events leading to withdrawal from the trial. Vaccine efficacy against Covid-19 was 91.3% (95% confidence interval [CI], 89.0 to 93.2) through 6 months of follow-up among the participants without evidence of previous SARS-CoV-2 infection who could be evaluated. There was a gradual decline in vaccine efficacy. Vaccine efficacy of 86 to 100% was seen across countries and in populations with diverse ages, sexes, race or ethnic groups, and risk factors for Covid-19 among participants without evidence of previous infection with SARS-CoV-2. Vaccine efficacy against severe disease was 96.7% (95% CI, 80.3 to 99.9). In South Africa, where the SARS-CoV-2 variant of concern B.1.351 (or beta) was predominant, a vaccine efficacy of 100% (95% CI, 53.5 to 100) was observed. Conclusions Through 6 months of follow-up and despite a gradual decline in vaccine efficacy, BNT162b2 had a favorable safety profile and was highly efficacious in preventing Covid-19. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728 .)

Robust Neutralizing Antibody Responses 6 Months Post Vaccination with BNT162b2: A Prospective Study in 308 Healthy Individuals

“…A persistent but declining antibody activity at six months post vaccination has been also reported for the mRNA-1273 [10,11]. Importantly, results from clinical trials have shown that BNT162b2 offers a robust protection from COVID-19 (91.3%, 95%CI: 89.0-93.2) at 6 months following vaccination [12].…”

Antibody responses against SARS-CoV-2 variants induced by four different SARS-CoV-2 vaccines

“…When neutralization activity against the original strain was limited, as observed after AZD1222 or Ad26.COV2.S vaccination, the capability to potently neutralize variants is severely diminished. The implication is that individuals receiving one of the adenovirus vector-based vaccines are more vulnerable to infection with the Beta and Delta VOCs, which is consistent with the lower efficacy of these vaccines against symptomatic infection with VOCs compared to the mRNA vaccines, although all vaccines are highly effective at preventing severe disease by VOCs [2][3][4][5][12][13][14][15][16][17] .…”

Effectiveness of mRNA and ChAdOx1 COVID-19 vaccines against symptomatic SARS-CoV-2 infection and severe outcomes with variants of concern in Ontario

“…Vaccine efficacy against symptomatic infection >14 days after the second dose was reported to be 70% (95% confidence interval [CI]: 44 to 85%) 3 against Alpha and 10% (95% CI, -77 to 55%) 4 against Beta for ChAdOx1 (AstraZeneca Vaxzevria). Efficacy against infection by Beta >7 days after the second dose for BNT162b2 (Pfizer-BioNTech Comirnaty) was 100% (95% CI, 54 to 100%) 5 . Few observational studies have reported the effectiveness of COVID-19 vaccines against infection or severe outcomes caused by VOCs [6][7][8][9][10][11] .…”