Genomic Surveillance of SARS-CoV-2 in Healthcare Workers: A Critical Sentinel Group for Monitoring the SARS-CoV-2 Variant Shift

The COVID-19 pandemic has left a legacy in the management of health emergencies, but sentinel surveillance was relatively underused, despite its significant role in decision-making during epidemics. Here we describe a sentinel SARS-CoV-2 antigens serosurveillance carried out on a cohort of 395 individuals at a Brazilian institution, from October 2020 to December 2022. A total of 1,507 serum samples were analyzed for IgG and IgA against SARS-CoV-2 Spike (S) or nucleocapsid (N) proteins, in the pre- and post-vaccination periods. The latter included two doses of CoronaVac (group 1, G1), or ChAdOx-1 or BNT162b2 (group 2, G2), followed by heterologous booster doses. In the pre-vaccination phase, 26.5% of participants showed IgG positivity for S and 13.7% for N. After the vaccines first dose, S IgG response was positive in 66.6% or 98% of G1 or G2 participants, respectively, while 100% of the participants showed S IgG positivity after the second dose, and S IgG and IgA after the booster. This initiative enabled the examination of viral transmission beyond hospital environments, which is rarely explored in existing literature, and established protocols for managing future emergencies. In addition, a serum bank and a comprehensive database were established, now available to the scientific community.

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Surveillance of SARS-CoV-2 in Healthcare Workers Before and After COVID-19 Vaccination: A Cohort Study in a Primary Care Unit of Brazil

Torres,

de Brito,

de Araújo

et al. 2024

Healthcare

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Introduction: Healthcare workers (HCWs) are at higher risk of SARS-CoV-2 infection. Viral surveillance for early detection of COVID-19 is a critical strategy to understand this population’s infection dynamics and prevent transmission. The study examines SARS-CoV-2 infection and reinfection among HCWs vaccinated against COVID-19 working at a primary healthcare unit serving a disenfranchised community in Brazil. Methods: The study was conducted in Cidade Estrutural, Federal District, Brazil, between February and October 2021. Participants were interviewed and provided samples. A prospective open cohort study was used to analyze the frequency of SARS-CoV-2 infection and reinfection, and the vaccine-induced seroconversion. Nasopharyngeal swab specimen was collected from workers presenting with flu-like symptoms and subjected to RT-qPCR. Peripheral blood samples were also collected every 30 ± 2 days for eight months, starting from the day participants received their first dose of COVID-19 vaccine, and submitted to serological testing (IgM and IgG chemiluminescence). The frequencies of infection and reinfection (RT-qPCR positive results 90 days after the infection) were calculated along with their respective confidence intervals (95% CI). Results: Of the 128 workers, 61 (47.65%; CI: 39.19–56.25) reported probable SARS-CoV-2 infection before vaccination and 50 (39.06%; CI: 31.04–47.71) had SARS-CoV-2 infection after vaccination, confirmed by molecular test. Reinfection was identified in seven workers (7/50, 14%; CI: 6.95–26.18) based on the 90-day interval between results. The serological data from the 128 workers during the cohort indicated that 68 (53.12%; CI: 44.5–61.5) had IgG antibodies and 46 had IgM antibodies (35.93%; CI: 28.14–44.54) against SARS-CoV-2. SARS-CoV-2 infection was common in 56% of the community health workers (CHWs), 50% of registered nurses, and licensed vocational nurses (33%). Following the COVID-19 vaccination, the percentage of infections among HCWs decreased from 47.83% to 4.35%. Conclusion: These results demonstrate that (i) approximately 40% of the workers were infected with SARS-CoV-2 in 2021 and (ii) reinfections confirmed by RT-qPCR occurred in 14% of the HCWs after vaccination. The results provide valuable insights into the circulation of SARS-CoV-2 among HCWs in a primary care unit serving a minoritized community.

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Genomic Surveillance of SARS-CoV-2 in Healthcare Workers: A Critical Sentinel Group for Monitoring the SARS-CoV-2 Variant Shift

Cited by 4 publications

References 31 publications

Molecular epidemiology of SARS-CoV-2 genome sentinel surveillance in commercial COVID-19 testing sites targeting asymptomatic individuals during Japan’s seventh epidemic wave

Molecular epidemiology of SARS-CoV-2 genome sentinel surveillance in commercial COVID-19 testing sites targeting asymptomatic individuals during Japan’s seventh epidemic wave

An institutional COVID-19 initiative: creation of a biobank and serological data analysis in pre- and post-vaccination cohorts

Surveillance of SARS-CoV-2 in Healthcare Workers Before and After COVID-19 Vaccination: A Cohort Study in a Primary Care Unit of Brazil

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