Waning of BNT162b2 Vaccine Protection against SARS-CoV-2 Infection in Qatar

Hiam Chemaitelly ¹, Patrick Tang ¹, Mohammad R Hasan ¹

⁰From the Infectious Disease Epidemiology Group (H.C., S.A., L.J.A.-R.) and the World Health Organization Collaborating Center for Disease Epidemiology Analytics on HIV/AIDS, Sexually Transmitted Infections, and Viral Hepatitis (H.C., S.A., L.J.A.-R.), Weill Cornell Medicine-Qatar, Cornell University, Qatar Foundation-Education City, the Department of Pathology, Sidra Medicine (P.T., M.R.H.), the Biomedical Research Center, Member of QU Health (H.M.Y., F.M.B., H.A.A.K., P.C., G.K.N.), the Departments of Biomedical Science (H.M.Y., F.M.B., H.A.A.K., G.K.N.) and Public Health (H.F.A.R., L.J.A.-R.), College of Health Sciences, and the Mathematics Program, Department of Mathematics, Statistics, and Physics, College of Arts and Sciences (H.H.A.), Qatar University, Hamad Medical Corporation (P.C., Z.A.K., E.A.K., A.J., A.H.K., A.N.L., R.M.S., A.A.B., A.A.K.), Primary Health Care Corporation (M.G.A.K.), and the Ministry of Public Health (H.E.A.R., M.H.A.-T., R.B.) - all in Doha, Qatar; Wellcome-Wolfson Institute for Experimental Medicine, Queens University, Belfast, United Kingdom (P.C.); and the Department of Population Health Sciences, Weill Cornell Medicine, Cornell University, New York (A.A.B., L.J.A.-R.).

The New England Journal of Medicine +

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October 6, 2021

View abstract on PubMed

Summary

Protection from the Pfizer-BioNTech vaccine against SARS-CoV-2 infection wanes quickly after the second dose. However, vaccine effectiveness against severe Covid-19, hospitalization, and death remains strong for at least six months.

Area Of Science

Immunology
Vaccinology
Epidemiology

Background

Waning vaccine immunity against SARS-CoV-2 (Covid-19) is a significant public health concern.
The long-term effectiveness of the BNT162b2 (Pfizer-BioNTech) vaccine against infection and disease, particularly during periods dominated by the beta and delta variants, remains unclear.

Purpose Of The Study

To assess the persistence of BNT162b2 vaccine effectiveness against SARS-CoV-2 infection and severe Covid-19 in Qatar.
To evaluate vaccine effectiveness over time following primary vaccination against different Covid-19 outcomes.

Main Methods

A matched test-negative, case-control study design was employed.
Data were collected from January 1 to September 5, 2021, encompassing mass polymerase-chain-reaction testing.

Main Results

BNT162b2 effectiveness against any SARS-CoV-2 infection peaked at 77.5% one month after the second dose, declining to approximately 20% by 5-7 months post-vaccination.
Effectiveness against symptomatic and asymptomatic infections waned similarly, as did variant-specific effectiveness.
Protection against severe, critical, or fatal Covid-19 reached over 96% within two months after the second dose and remained robust for six months.

Conclusions

BNT162b2 vaccine-induced protection against SARS-CoV-2 infection wanes considerably after the second dose.
Protection against severe Covid-19, hospitalization, and death persists at a high level for at least six months post-vaccination.

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