Abstract
Objectives: To estimate the prevalence, incidence and longevity of antibodies against SARS-CoV-2 among primary healthcare providers (PHCPs).
Design: Prospective cohort study with 12 months of follow-up.
Setting: Primary care in Belgium.
Participants: Any general practitioner (GP) working in primary care in Belgium and any other PHCP from the same GP practice who physically manages (examines, tests, treats) patients were eligible. A convenience sample of 3648 eligible PHCPs from 2001 GP practices registered for this study (3044 and 604 to start in December 2020 and January 2021, respectively). 3390 PHCPs (92,9%) participated in their first testing time point (2820 and 565, respectively) and 2557 PHCPs (70,1%) in the last testing time point (December 2021).
Interventions: Participants were asked to perform a rapid serological test targeting IgM and IgG against the receptor binding domain of SARS-CoV-2 and to complete an online questionnaire at each of maximum eight testing time points.
Primary and secondary outcome measures: The prevalence, incidence and longevity of antibodies against SARS-CoV-2 both after natural infection and after vaccination.
Results: Among all participants, 67% were women and 77% GPs. Median age was 43 years. The seroprevalence in December 2020 (before vaccination availability) was 15.1% (95% CI 13.5% to 16.6%), increased to 84.2% (95% CI 82.9% to 85.5%) in March 2021 (after vaccination availability) and reached 93.9% (95% CI 92.9% to 94.9%) in December 2021 (during booster vaccination availability and fourth (delta variant dominant) COVID-19 wave). Among not (yet) vaccinated participants the first monthly incidence of antibodies against SARS-CoV-2 was estimated to be 2.91% (95% CI 1.80% to 4.01%). The longevity of antibodies is higher in PHCPs with self-reported COVID-19 infection.
Conclusions: This study confirms that occupational health measures provided sufficient protection when managing patients. High uptake of vaccination resulted in high seroprevalence of SARS-CoV-2 antibodies in PHCPs in Belgium. Longevity of antibodies was supported by booster vaccination and virus circulation.
Trial registration number: NCT04779424 .
Keywords: COVID-19; Epidemiology; GENERAL MEDICINE (see Internal Medicine); PRIMARY CARE.
【저자키워드】 COVID-19, primary care, Epidemiology, general medicine (see internal medicine), 【초록키워드】 serological test, SARS-CoV-2, primary care, vaccination, antibody, variant, virus, cohort study, Receptor binding domain, Prevalence, Health, SARS-CoV-2 antibody, COVID-19 infection, Prospective, Patient, age, Follow-up, women, circulation, incidence, Longevity, natural infection, Belgium, Care, questionnaire, patients, booster vaccination, IgM and IgG, Healthcare provider, Participants, 95% CI, measure, Registered, participant, secondary outcome, dominant, Complete, internal, physically, eight, provided, supported, reached, asked, eligible, participated, 【제목키워드】 SARS-CoV-2, antibody, prospective cohort study, Follow-up, incidence, Healthcare provider,