Introduction. Vaccination against SARS-CoV-2 infection has been shown to reduce the severity of infection; however, the overall reinfection rate in those unvaccinated, partially vaccinated and fully vaccinated remains unclear. Therefore, this study was undertaken to elucidate the rates and associated factors for such occurrences.Methods. This was a retrospective epidemiological report analysing 1362 COVID-19 reinfection cases in the Kingdom of Bahrain between April 2020 and July 2021. The differences in disease severity and characteristics of reinfection between various levels of vaccination statuses were determined among fully vaccinated, interrupted vaccination (positive test less than 14 days after receiving the second dose of vaccine), one dose of vaccination, post-reinfection vaccination and unvaccinated. Data were collected from the National COVID-19 Contact Tracing Team Database of individuals who tested positive for SARS-CoV-2.Results. During the study, reinfection cases increased from zero cases per month in April – June 2020 to a sharp peak of 579 reinfection cases in May 2021 followed by a rapid decline. Males constituted a significantly larger proportion of reinfections (n=821, 60.3%) than females (39.7%) (p<0.0001). Reinfection episodes were highest amongst the 30-39 years of age (n=405, 29.7%). The rate of reinfection increased with time from the initial infection with the lowest reinfection rate occurring at 3-6 months after the first infection (n=281, 20.6%) and the highest episodes occurring ≥9 months after initial infection (n=632, 46.4%). Comparison of the symptomatology between initial infection and reinfection episode for each individual showed that most individuals were asymptomatic during both episodes (n=486, 35.7%), while 265 (19.5%) individuals were symptomatic during both episodes. Reinfection disease severity was mild and differed across the cohort (X2 test p=0.003) with vaccinated patients less likely to have symptomatic reinfection (OR 0·71, p=0·004). Only 89 (6.6%) reinfection cases required hospitalization and there were no deaths (Poisson exact, 97.5% Cl 2.7 per 1000).Conclusion. Vaccine induced immunity and prior infection with or without vaccination were effective in reducing disease severity of reinfection episodes.