The Effectiveness of the Two-Dose BNT162b2 Vaccine: Analysis of Real-World Data

Abstract

Background COVID-19 mRNA vaccines were shown to be highly efficacious in preventing the disease in randomized controlled trials; nonetheless, evidence on the real-world effectiveness of this vaccine is limited. Study objective was to evaluate the effectiveness of BNT162b2 vaccine in preventing SARS-CoV-2 infection and COVID-19-related hospitalization and mortality. Methods This historical cohort study included members of a large health provider in Israel that were vaccinated with at least one dose of BNT162b2. The primary outcome was incidence rate of a SARS-CoV-2 infection confirmed with rt-PCR, between 7 to 27 days after second dose (protection-period), as compared to days 1 to 7 after the first dose, where no protection by the vaccine is assumed (reference-period). Results Data of 1,178,597 individuals vaccinated with BNT162b2 were analyzed (mean age 47.7 years [SD=18.1], 48.4% males) of whom 872,454 (74.0%) reached the protection period. Overall, 4514 infections occurred during the reference period compared to 728 during the protection period, yielding a weighted mean daily incidence of 54.8 per 100,000 (95%CI: 26.1-115.0 per 100,000) and 5.4 per 100,000 (95%CI: 3.5-8.4 per 100,000), respectively. The vaccine effectiveness in preventing infection was 90% (95%CI:79%- 95%) and 94% (95%CI:88%-97%) against COVID-19. Among immunosuppressed patients, vaccine effectiveness against infection was 71% (95%CI:37%-87%). The adjusted hazard ratios for hospitalization in those infected were 0.82 (95%CI:0.36-1.88), 0.45 (95%CI:0.23-0.90), and 0.56 (95%CI:0.36-0.89) in the age groups 16-44, 45-64 and 75 and above, respectively. Conclusions The effectiveness of the BNT162b2 vaccine is comparable to the one reported in the phase III clinical trial.

SARS-CoV-2 Portrayed against HIV: Contrary Viral Strategies in Similar Disguise

“…Prolonged viral replication in immunocompromised hosts may favor the generation and selection of nAb escape mutants, which in turn drives Ab affinity maturation and eventually enhanced neutralization breadth and potency [ 223 ]. In humans, previous SARS-CoV-2 infection and anti-spike Ab seropositivity significantly reduce the risk of SARS-CoV-2 reinfection [ 215 , 224 , 225 , 226 , 227 , 228 , 229 ], which is in line with vaccination outcome analyses [ 230 , 231 , 232 , 233 , 234 , 235 , 236 ] altogether implying that SARS-CoV-2 binding and/or nAbs exert protective effects. Consequently, neutralization levels have been found highly predictive of immune protection with seven current vaccines and in convalescent cohorts, and provide an evidence-based model of SARS-CoV-2 immune protection [ 237 ].…”

Dominance of Alpha and Iota variants in SARS-CoV-2 vaccine breakthrough infections in New York City

“…The Janssen COVID-19 vaccine, JNJ-78436735, was also deployed shortly after the mRNA vaccines, and these vaccines were shown to have high efficacy in clinical trials [3][4][5] . With millions of people vaccinated in multiple countries, they have proven to be highly effective in the real world [6][7][8][9][10][11][12] , although a very small percentage of breakthrough infections have occurred, as expected [13][14][15][16][17][18][19][20][21] . Contemporaneously with the vaccination efforts in several countries, new SARS-CoV-2 variants emerged, four of which were designated by the WHO as variants of concern (VOC), B.1.1.7 or Alpha, B.1.351 or Beta, P.1 or Gamma, and B.1.617.2 or Delta, which arose originally in the UK, South Africa, Brazil, and India, respectively 22,23 .…”

Multisociety statement on coronavirus disease 2019 (COVID-19) vaccination as a condition of employment for healthcare personnel

“…The growing number of real-world studies show similar overall vaccine effectiveness for preventing symptomatic and asymptomatic COVID-19. Studies assessing immunogenicity and limited vaccine effectiveness data suggest that vaccine effectiveness is likely lower for immunocompromised persons (15)(16)(17) (18,19). These findings, amongst other real-world data, suggest that vaccination reduces the likelihood of COVID-19 transmission from infected persons to their contacts, including household contacts (20)(21)(22).…”