Seroprevalence of SARS-CoV-2 Antibodies among vaccinated and non-vaccinated adults in the West Bank: Results of a repeated cross-sectional study

Abstract

BackgroundSeroprevalence studies provide an accurate measure of SARS-CoV-2 spread at a population level and the number of undiagnosed individuals. Repeated cross-sectional sero-studies are encouraged to monitor the spread of the virus. The aim of this study is to assess the seroprevalence rate among a random sample of Palestinians residing in the West Bank region of Palestine.MethodsThis second round cross-sectional study involved 1451 participants. serologic testing of a random sample of vaccinated and non-vaccinated adults, 18 years and older residing in 11 governorates of the West Bank region of Palestine. Antibodies/Blood samples were taken using Elecsys Anti-SARS-CoV-2 assay by using the Cobas Analyzer cobas e 411 (Roche) for detection of antibody seropositivity against COVID-19.Serological tests for 910 adequate serum samples were done using immunoassays for detection of antibodies against SARS-CoV-2. Sociodemographic information and medical history data was collected.ResultsStudy findings indicate that as of October 2021, a seroprevalence rate of 75.9% (30% due to infection with Covid-19 virus and 45.9% due to vaccination), 95% CI (73.1-78.7). The results indicate that the prevalence of antibodies among those who unvaccinated and undiagnosed cases was 45.2% with 95% CI (39.9-50.5%).The average age of participants was 37.6 years old. 49.2% were female and 50.8% were male. In relation to COVID-19, the following was found:ConclusionOur findings reveal a drastic rise in seroprevalence of SARS-CoV-2 antibodies both due to infection and due to vaccination. This information is useful for assessing the degree of herd immunity, and provides better understanding of the pandemic. Population-based seroprevalence studies should be conducted periodically to monitor the SARS-CoV-2 seroprevalence in Palestine and inform policymakers about the efficacy of the surveillance system and the public compliance with vaccination policies.