Increased risk of infection with SARS-CoV-2 Beta, Gamma, and Delta variant compared to Alpha variant in vaccinated individuals
The extent to which severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC) break through infection- or vaccine-induced immunity is not well understood. Here, we analyze 28,578 sequenced SARS-CoV-2 samples from individuals with known immune status obtained through national community testing in the Netherlands from March to August 2021. We find evidence for an increased risk of infection by the Beta (B.1.351), Gamma (P.1), or Delta (B.1.617.2) variants compared to the Alpha (B.1.1.7) variant after vaccination. No clear differences were found between vaccines. However, the effect was larger in the first 14-59 days after complete vaccination compared to 60 days and longer. In contrast to vaccine-induced immunity, no increased risk for reinfection with Beta, Gamma or Delta variants relative to Alpha variant was found in individuals with infection-induced immunity.
Competing Interest Statement
The authors have declared no competing interest.
This work was funded by the Ministry of Health, Welfare and Sports (VWS).
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The Centre for Clinical Expertise at the RIVM assessed the research proposal following the specific conditions as stated in the law for medical research involving human subjects (WMO). In their opinion the research does not fulfill one or both of these conditions and therefore conclude it is exempted for further approval by the ethical research committee. Pathogen surveillance is a legal task of the RIVM (artikel 3 Wet RIVM, article 3 Law RIVM) and is carried out under the responsibility of the Minister of Health, Welfare and Sports (VWS). Article 6c (artikel 6c) of the Public Health Act (Wet Publieke Gezondheid) provides that RIVM may receive pseudonymised data for this task without individual consent of each case.
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