SARS-CoV-2 Reinfection Rate and Outcomes in Saudi Arabia: A National Retrospective Study

• Published in: International journal of infectious diseases Vol. 122; pp. 758 - 766
• Main Authors: Al-Otaiby, Maram, Krissaane, Ines, Al Seraihi, Ahad, Alshenaifi, Jumanah, Qahtani, Mohammad Hassan, Aljeri, Thamer, Zaatari, Ezzedine, Hassanain, Mazen, Algwizani, Abdullah, Albarrag, Ahmed, Al-Mozaini, Maha, Alabdulaali, Mohammed
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.09.2022; The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases; Elsevier
• Subjects: COVID-19 - epidemiology; COVID-19 Vaccines; Humans; Protective Immunity; Reinfection - epidemiology; Retrospective Studies; Risk Factor; SARS-CoV-2; SARS-CoV-2 Reinfection; Saudi Arabia; Saudi Arabia - epidemiology; Vaccination; Variant Of Concern; Saudi Arabia; Saudi Arabia; SARS-CoV-2 Reinfection; Protective Immunity; Variant Of Concern; Risk Factor; Vaccination
• ISSN: 1201-9712; 1878-3511; 1878-3511
• DOI: 10.1016/j.ijid.2022.07.025

•SARS-CoV-2 reinfection was estimated at 0.8% over a 20-month follow-up in Saudi Arabia.•Diabetes, HIV, obesity, and working in health care were associated with reinfections.•Two vaccine doses were associated with 87% risk reduction of reinfection.•Delta-induced immunity may not be sufficient to prevent subsequent infections.•Previous infection and vaccination confer strong protection against severe COVID-19. The characterization of reinfection with SARS-CoV-2 has been a subject of concern and controversy, especially with the surge of infections with highly transmissible variants worldwide. This retrospective national study used comorbidities, vaccination status, SARS-CoV-2 variants of concern, and demographics data to profile participants who were reinfected with SARS-CoV-2, defined as having two reverse transcriptase-polymerase chain reaction-positive SARS-CoV-2 tests within at least 90 days apart. A multivariate logistic regression model assessed the risk factors associated with reinfection . Two control groups were selected: nonreinfected participants reporting a positive test (control group one) and those reporting a negative test (control group two). Between March 2020 and December 2021, 4454 reinfected participants were identified in Saudi Arabia (0.8%, 95% confidence interval [CI] 0.7-0.8). The majority (67.3%) were unvaccinated (95% CI 65.9-68.7) and 0.8% (95% CI 0.6-1.1) had severe or fatal SARS-CoV-2 disease. COVID-19 vaccines were 100% effective against mortality in reinfected individuals who received at least one dose, whereas it conferred 61% (odds ratio [OR] 0.4, 95% CI 0.1-1.0) additional protection against severe disease after the first dose and 100% after the second dose. In the risk factor analysis, reinfection was highly associated with comorbidities, such as HIV (OR 2.5, 95% CI 1.3-5.2; P = 0.009), obesity (OR 2.3, 95% CI 1.3-3.9; P = 0.003), pregnancy (OR 3.2, 95% CI 1.4-7.4; P = 0.005), and working in health care facilities (OR 6.1, 95% CI 3.1-12.9; P <0.0001). The delta variant (B.1.617.2) was the most frequent variant of concern among the reinfected cohort. This in-depth study of the reinfection profile identified risk factors and highlighted the associated SARS-CoV-2 variants. Results showed that naturally acquired immunity to SARS-CoV-2 through multiple reinfections together with vaccine-induced immunity provided substantial protection against severe SARS-CoV-2 disease and mortality.