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. 2021 Dec;174(12):1770-1772.
doi: 10.7326/M21-3486. Epub 2021 Oct 19.

Asymptomatic SARS-CoV-2 Vaccine Breakthrough Infections in Health Care Workers Identified Through Routine Universal Surveillance Testing

Federica Novazzi  1 , Stefano Taborelli  2 , Andreina Baj  3 , Daniele Focosi  4 , Fabrizio Maggi  3
Affiliations

Asymptomatic SARS-CoV-2 Vaccine Breakthrough Infections in Health Care Workers Identified Through Routine Universal Surveillance Testing

Federica Novazzi et al. Ann Intern Med. 2021 Dec.
No abstract available

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Conflict of interest statement

Disclosures: Authors have reported no disclosures of interest. Forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M21-3486.

Figures

Figure.
Figure.. PCR Cts for SARS-CoV-2 cases among HCWs and community COVID-19 cases during the study period.
Circles indicate asymptomatic infection, and squares indicate symptomatic infection. The color indicates Alpha variant (green), Delta variant (blue), or undefined strain (black). Arrows indicate attribution based on spike gene sequencing. Ct = cycle threshold; HCW = health care worker; PCR = polymerase chain reaction. A. All asymptomatic and symptomatic cases. B. Cases among HCWs screened every 2 wk working in wards deemed to have high exposure risk (hematology, pediatric oncohematology, general oncology, gynecologic oncology, dialysis and nephrology, general and transplant surgery, infectious diseases, and neonatal intensive care unit). C. Cases among HCWs screened every 4 wk working in wards deemed to have moderate exposure risk (radiotherapy, thoracic surgery, heart surgery, rheumatology, pneumology, COVID hub 1, COVID hub 2, and emergency department). D. Weekly positive SARS-CoV-2 PCR incidence rate in the area of Insubria, Italy (where HCWs resided), during the study period.
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References

    1. Farinholt T , Doddapaneni H , Qin X , et al. Transmission event of SARS-CoV-2 Delta variant reveals multiple vaccine breakthrough infections. med. Rxiv. 2021. [PMID: ] doi:10.1101/2021.06.28.21258780 - DOI - PMC - PubMed
    1. Riemersma KK, Grogan BE, Kita-Yarbro A, et al. Vaccinated and unvaccinated individuals have similar viral loads in communities with a high prevalence of the SARS-CoV-2 delta variant. medRxiv. Preprint posted online 31 July 2021. doi:10.1101/2021.07.31.21261387
    1. Benenson S , Oster Y , Cohen MJ , et al. BNT162b2 mRNA Covid-19 vaccine effectiveness among health care workers [Letter]. N Engl J Med. 2021;384:1775-1777. [PMID: ] doi:10.1056/NEJMc2101951 - DOI - PMC - PubMed
    1. Keehner J , Horton LE , Pfeffer MA , et al. SARS-CoV-2 infection after vaccination in health care workers in California [Letter]. N Engl J Med. 2021;384:1774-1775. [PMID: ] doi:10.1056/NEJMc2101927 - DOI - PMC - PubMed
    1. Rovida F, Cassaniti I, Paolucci S, et al. SARS-CoV-2 vaccine breakthrough infections are asymptomatic or mildly symptomatic and are infrequently transmitted. medRxiv. Preprint posted online 3 July 2021. doi:10.1101/2021.06.29.21259500

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