LAUSR

Background Seroprevalence studies are known to provide better estimates of the proportion of people previously infected, which did not undertake diagnostic testing. Repeated cross-sectional sero-studies are encouraged in the same locations to monitor trends overtime. The aim of this study was to assess the seroprevalence among a random sample of vaccinated and non-vaccinated Palestinian adults living in the West Bank region of Palestine, irrespective of the source of antibodies, be it due to infection with COVID-19 or due to vaccination or both. Methods This repeated cross-sectional study used serologic testing on 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. Seroprevalence was estimated as the proportion of individuals who had a positive result in the total SARS-CoV-2 antibodies in the immunoassay. Sociodemographic information and medical history data was collected using a questionnaire. Results Among 1451 total participants enrolled in the study, serum samples were tested from 910 persons. Study findings from this randomly selected sample indicated a seroprevalence 75.9%, 95% CI (73.1-78.7). The seroprevalence results indicated that the prevalence of antibodies among those who reported that they were not infected and did not get vaccinated 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: Conclusion Our findings revealed a drastic rise in seroprevalence of SARS-CoV-2 antibodies. This information is useful for assessing the degree of herd immunity, and provides for 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.