Waning of BNT162b2 vaccine protection against SARS-CoV-2 infection in Qatar

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View ORCID ProfileHiam Chemaitelly, View ORCID ProfilePatrick Tang, Mohammad Rubayet Hasan, View ORCID ProfileSawsan AlMukdad, View ORCID ProfileHADI M. YASSINE, View ORCID ProfileFatiha Benslimane, Hebah A. Al Khatib, View ORCID ProfilePeter Coyle, View ORCID ProfileHoussein H. Ayoub, View ORCID ProfileZaina Al Kanaani, View ORCID ProfileEinas Al Kuwari, View ORCID ProfileAndrew Jeremijenko, View ORCID ProfileAnvar Hassan Kaleeckal, Ali Nizar Latif, View ORCID ProfileRiyazuddin Mohammad Shaik, View ORCID ProfileHanan F. Abdul Rahim, View ORCID ProfileGheyath Nasrallah, View ORCID ProfileMohamed Ghaith Al Kuwari, Hamad Eid Al Romaihi, Adeel A Butt, View ORCID ProfileMohamed H. Al-Thani, Abdullatif Al Khal, View ORCID ProfileRoberto Bertollini, View ORCID ProfileLaith J Abu-Raddad
doi: https://doi.org/10.1101/2021.08.25.21262584

This article is a preprint and has not been certified by peer review [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

BACKGROUND: Waning of vaccine protection against SARS-CoV-2 infection or COVID-19 disease is a concern. This study investigated persistence of BNT162b2 (Pfizer-BioNTech) vaccine effectiveness against infection and disease in Qatar, where the Beta and Delta variants have dominated incidence and PCR testing is done at a mass scale. METHODS: A matched test-negative, case-control study design was used to estimate vaccine effectiveness against SARS-CoV-2 infection and against any severe, critical, or fatal COVID-19 disease, between January 1, 2021 to August 15, 2021. RESULTS: Estimated BNT162b2 effectiveness against any infection, asymptomatic or symptomatic, was negligible for the first two weeks after the first dose, increased to 36.5% (95% CI: 33.1-39.8) in the third week after the first dose, and reached its peak at 72.1% (95% CI: 70.9-73.2) in the first five weeks after the second dose. Effectiveness declined gradually thereafter, with the decline accelerating ≥15 weeks after the second dose, reaching diminished levels of protection by the 20th week. Effectiveness against symptomatic infection was higher than against asymptomatic infection, but still waned in the same fashion. Effectiveness against any severe, critical, or fatal disease increased rapidly to 67.7% (95% CI: 59.1-74.7) by the third week after the first dose, and reached 95.4% (95% CI: 93.4-96.9) in the first five weeks after the second dose, where it persisted at about this level for six months. CONCLUSIONS: BNT162b2-induced protection against infection appears to wane rapidly after its peak right after the second dose, but it persists at a robust level against hospitalization and death for at least six months following the second dose.  


Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

The authors are grateful for institutional salary support from the Biomedical Research Program and the Biostatistics, Epidemiology, and Biomathematics Research Core, both at Weill Cornell Medicine-Qatar, as well as for institutional salary support provided by the Ministry of Public Health and Hamad Medical Corporation. The authors are also grateful for the Qatar Genome Programme for institutional support for the reagents needed for the viral genome sequencing. The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the article. Statements made herein are solely the responsibility of the authors.

Author Declarations

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.


The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was approved by the Hamad Medical Corporation and Weill Cornell Medicine-Qatar Institutional Review Boards with waiver of informed consent.

All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.


I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).


I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.


Paper in collection COVID-19 SARS-CoV-2 preprints from medRxiv and bioRxiv

Paper in collection COVID-19 SARS-CoV-2 preprints from medRxiv and bioRxiv

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