ABSTRACT
INTRODUCTION: Knowledge of the seroprevalence and duration of antibodies against SARS-CoV-2 was needed in the early phases of the COVID-19 pandemic and is still necessary for policy makers and healthcare professionals. This information allows us to better understand the risk of reinfection in previously infected individuals. METHODS: We investigated the prevalence and duration of detectable antibodies against SARS-CoV-2 in sequentially collected samples from 379 healthcare professionals. RESULTS: SARS-CoV-2 seroprevalence at inclusion was 5.3% (95% confidence interval (CI): 3.3-8.0%) and 25% of seropositive participants reverted during follow-up. At the end of follow-up, the calculated probability of having detectable antibodies among former seropositive participants was 72.2% (95% CI: 54.2-96.2%). CONCLUSION: Antibodies against SARS-CoV-2 were detectable in a subset of infected individuals for a minimum of 39 weeks. FUNDING: The assays performed at Rigshospitalet were developed with financial support from the Carlsberg Foundation (CF20-0045) and the Novo Nordisk Foundation (NFF205A0063505 and NNF20SA0064201). TRIAL REGISTRATION: The study was registered with the Danish National Committee on Health Research Ethics (H-20022312).
Subject(s)
COVID-19 , Pandemics , Antibodies, Viral , COVID-19/epidemiology , Health Personnel , Humans , Prevalence , SARS-CoV-2 , Seroepidemiologic StudiesABSTRACT
SARS-CoV-2 IgG screening of 1,000 antenatal serum samples in the Oxford area, United Kingdom, between 14 April and 15 June 2020, yielded a 5.3% seroprevalence, mirroring contemporaneous regional data. Among the 53 positive samples, 39 showed in vitro neutralisation activity, correlating with IgG titre (Pearson's correlation p<0.0001). While SARS-CoV-2 seroprevalence in pregnancy cohorts could potentially inform population surveillance, clinical correlates of infection and immunity in pregnancy, and antenatal epidemiology evolution over time need further study.
