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. 2022 Apr 21;10(5):857.
doi: 10.3390/microorganisms10050857.

SARS-CoV-2 Vaccine Alpha and Delta Variant Breakthrough Infections Are Rare and Mild but Can Happen Relatively Early after Vaccination

Jelissa Katharina Peter  1 , Fanny Wegner  2   3   4 , Severin Gsponer  1 , Fabrice Helfenstein  5 , Tim Roloff  2   3   4 , Rahel Tarnutzer  1 , Kerstin Grosheintz  1 , Moritz Back  1 , Carla Schaubhut  1 , Sabina Wagner  1 , Helena M B Seth-Smith  2   3   4 , Patrick Scotton  6 , Maurice Redondo  7 , Christiane Beckmann  7 , Tanja Stadler  8 , Andrea Salzmann  7 , Henriette Kurth  7 , Karoline Leuzinger  9   10 , Stefano Bassetti  11 , Roland Bingisser  12 , Martin Siegemund  13 , Maja Weisser  14 , Manuel Battegay  14 , Sarah Tschudin Sutter  14 , Aitana Lebrand  4 , Hans H Hirsch  7   10   14 , Simon Fuchs  1 , Adrian Egli  2   3
Affiliations

SARS-CoV-2 Vaccine Alpha and Delta Variant Breakthrough Infections Are Rare and Mild but Can Happen Relatively Early after Vaccination

Jelissa Katharina Peter et al. Microorganisms. .

Abstract

(1) Background: Some COVID-19 vaccine recipients show breakthrough infection. It remains unknown, which factors contribute to risks and severe outcomes. Our aim was to identify risk factors for SCoV2 breakthrough infections in fully vaccinated individuals. (2) Methods: We conducted a retrospective case-control study from 28 December 2020 to 25 October 2021. Data of all patients with breakthrough infection was compared to data of all vaccine recipients in the Canton of Basel-City, Switzerland. Further, breakthrough infections by Alpha- and Delta-variants were compared. (3) Results: Only 0.39% (488/126,586) of all vaccine recipients suffered from a breakthrough infection during the observational period, whereof most cases were asymptomatic or mild (97.2%). Breakthrough infections after full vaccination occurred in the median after 78 days (IQR 47-123.5). Factors with lower odds for breakthrough infection were age (OR 0.987) and previous COVID-19 infection prior to vaccination (OR 0.296). Factors with higher odds for breakthrough infection included vaccination with Pfizer/BioNTech instead of Moderna (OR 1.459), chronic disease (OR 2.109), and healthcare workers (OR 1.404). (4) Conclusions: Breakthrough infections are rare and mild but can occur early after vaccination. This implies that booster vaccination might be initiated earlier, especially for risk groups. Due to new variants emerging repeatedly, continuous monitoring of breakthrough infections is crucial.

Keywords: Alpha; COVID-19; COVID-19 vaccine; Delta; Moderna; Pfizer/BioNTech; SARS-CoV-2; breakthrough infection.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Distribution time in days from full vaccination (as defined above) to the positive SCoV2 test result confirming all cases of breakthrough infection. (a) Absolute frequency; (b) cumulative frequency.
Figure 2
Figure 2
Distribution of dates of positive test for all patients with a breakthrough infection and according to age quartiles. In older patients (64 to 98 years old) first bulk of positive tests (from 1 March to 28 June 2021) is due to breakthrough infections caused by the Alpha variant.
See this image and copyright information in PMC

References

    1. Baden L.R., El Sahly H.M., Essink B., Kotloff K., Frey S., Novak R., Diemert D., Spector S.A., Rouphael N., Creech C.B., et al. Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N. Engl. J. Med. 2021;384:403–416. doi: 10.1056/NEJMoa2035389. - DOI - PMC - PubMed
    1. Dagan N., Barda N., Kepten E., Miron O., Perchik S., Katz M.A., Hernán M.A., Lipsitch M., Reis B., Balicer R.D. BNT162b2 mRNA COVID-19 Vaccine in a Nationwide Mass Vaccination Setting. N. Engl. J. Med. 2021;384:1412–1423. doi: 10.1056/NEJMoa2101765. - DOI - PMC - PubMed
    1. Polack F.P., Thomas S.J., Kitchin N., Absalon J., Gurtman A., Lockhart S., Perez J.L., Pérez Marc G., Moreira E.D., Zerbini C., et al. Safety and efficacy of the BNT162b2 mRNA COVID-19 vaccine. N. Engl. J. Med. 2020;383:2603–2615. doi: 10.1056/NEJMoa2034577. - DOI - PMC - PubMed
    1. Stephenson K.E., Le Gars M., Sadoff J., de Groot A.M., Heerwegh D., Truyers C., Atyeo C., Loos C., Chandrashekar A., McMahan K., et al. Immunogenicity of the Ad26.COV2.S Vaccine for COVID-19. JAMA J. Am. Med. Assoc. 2021;325:1535–1544. doi: 10.1001/jama.2021.3645. - DOI - PMC - PubMed
    1. Bergwerk M., Gonen T., Lustig Y., Amit S., Lipsitch M., Cohen C., Mandelboim M., Levin E.G., Rubin C., Indenbaum V., et al. COVID-19 Breakthrough Infections in Vaccinated Health Care Workers. N. Engl. J. Med. 2021;385:1474–1484. doi: 10.1056/NEJMoa2109072. - DOI - PMC - PubMed

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