Effectiveness of BNT162b2 mRNA COVID-19 vaccine against SARS-CoV-2 variant Beta (B.1.351) among persons identified through contact tracing in Israel: A prospective cohort study.

Shepherd R Singer,Sharon Alroy-Preis,Neta S Zuckerman,Itay Hazan,Netanel Ginish,Gabriel Mircus,Orna Mor,Jo Southern,Luis Jodar,Kaijie Pan,Marc Lipsitch,Ella Mendelson,Frederick J Angulo,David L Swerdlow,John M Mclaughlin,Emilia Anis,Yeheskel Levy,Oran Erster,Eric J Haas

doi:10.1016/j.eclinm.2021.101190

Abstract

BackgroundSARS-CoV-2 variant Beta (B.1.351) was designated as a Variant of Concern (VoC) after becoming the dominant strain in South Africa and spreading internationally. BNT162b2 showed lower levels of neutralizing antibodies against Beta than against other strains raising concerns about effectiveness of vaccines against infections caused by Beta. We estimated BNT162b2 vaccine effectiveness (VE) against Beta infections in Israel, a country with high vaccine uptake.MethodsThe Ministry of Health (MoH) identified Beta cases through mandatory reporting of SARS-CoV-2 cases and whole genome sequencing (WGS) of specimens from vaccination-breakthrough infections, reinfections, arriving international travelers, and a selection of other infected persons. A cohort analysis was conducted of exposure events of contacts of primary Beta cases. WGS was conducted on available PCR-positive specimens collected from contacts. VE estimates with 95% confidence intervals (CIs) against confirmed and probable Beta infections were determined by comparing infection risk between unvaccinated and fully-vaccinated (≥7 days after the second dose) contacts, and between unvaccinated and partially-vaccinated (<7 days after the second dose) contacts.FindingsMoH identified 310 Beta cases through Jun 27, 2021. During the study period (Dec 11, 2020 – Mar 25, 2021), 164 non-institutionalized primary Beta cases, with 552 contacts aged ≥16 years, were identified. 343/552 (62%) contacts were interviewed and tested. 71/343 (21%) contacts were PCR-positive. WGS was performed on 7/71 (10%) PCR-positive specimens; all were Beta. Among SARS-CoV-2-infected contacts, 48/71 (68%) were symptomatic, 10/71 (14%) hospitalized, and 2/71 (3%) died. Fully-vaccinated VE against confirmed or probable Beta infections was 72% (95% CI -5 – 97%; p=0·04) and against symptomatic confirmed or probable Beta infections was 100% (95% CI 19 – 100%; p=0·01). There was no evidence of protection in partially-vaccinated contacts.InterpretationIn a prospective observational study, two doses of BNT162b2 were effective against confirmed and probable Beta infections. Through the end of June 2021, introductions of Beta did not interrupt control of the pandemic in Israel.FundingIsrael Ministry of Health and Pfizer.

Highlights

The SARS-CoV-2 pandemic resulted in >180M cases and >3.9M deaths worldwide through Jun 27, 2021 [1] including 840 888 cases and 6 428 deaths in Israel [2].The Pfizer/BioNTech mRNA vaccine (BNT162b2), had 95% efficacy against symptomatic infections in a RCT [3]
A primary Beta case was defined as whole genome sequencing (WGS)-confirmed Beta case identified by Ministry of Health (MoH) surveillance activities other than MoH contact tracing program
The vaccine effectiveness (VE) estimate against symptomatic Beta infections in our study is comparable to the VE estimate (97%) against symptomatic Alpha infections by the MoH [8]

Summary

Introduction

The SARS-CoV-2 pandemic resulted in >180M cases and >3.9M deaths worldwide through Jun 27, 2021 [1] including 840 888 cases and 6 428 deaths in Israel [2] (population 9¢1M).The Pfizer/BioNTech mRNA vaccine (BNT162b2), had 95% efficacy against symptomatic infections in a RCT [3]. Israel launched a vaccination campaign on Dec 20, 2020 that quickly achieved high vaccine coverage and resulted in sustained declines in the incidence of SARS-CoV-2 infections [8]. A Ministry of Health (MoH) study during a period when 95% of specimens were variant Alpha reported VEs of >95% against infections, symptomatic infections, hospitalizations, deaths in Israel [8]. We estimated BNT162b2 vaccine effectiveness (VE) against Beta infections in Israel, a country with high vaccine uptake. Methods: The Ministry of Health (MoH) identified Beta cases through mandatory reporting of SARS-CoV-2 cases and whole genome sequencing (WGS) of specimens from vaccination-breakthrough infections, reinfections, arriving international travelers, and a selection of other infected persons. Among SARS-CoV-2-infected contacts, 48/71 (68%) were symptomatic, 10/71 (14%) hospitalized, and 2/71 (3%) died.

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Results

Conclusion