Evaluating the risk of SARS-CoV-2 reinfection with the Omicron or Delta variant in Wales, UK

• Published in: PloS one Vol. 19; no. 9; p. e0309645
• Main Authors: Postans, Mark, Pacchiarini, Nicole, Song, Jiao, Cottrell, Simon, Williams, Catie, Beazer, Andrew, Moore, Catherine, Connor, Thomas R, Williams, Christopher
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.09.2024; Public Library of Science (PLoS)
• Subjects: Adolescent; Adult; Aged; Child; Child, Preschool; Classification; COVID-19; COVID-19 - epidemiology; COVID-19 - virology; COVID-19 vaccines; Datasets; Disease transmission; Epidemiology; Ethics; Evaluation; Female; Gene sequencing; Genomics; Genotyping; Health surveillance; Humans; Incidence; Infant; Infections; Intervals; Male; Medical research; Medicine, Experimental; Metadata; Middle Aged; Mutation; Pathogens; Public health; Reinfection - epidemiology; Reinfection - virology; Risk; Risk factors (Health); SARS-CoV-2 - genetics; SARS-CoV-2 - isolation & purification; Severe acute respiratory syndrome coronavirus 2; Vaccination; Vaccines; Viral diseases; Wales - epidemiology; Whole genome sequencing; Young Adult; Wales; United Kingdom; United Kingdom > UK
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0309645

Recent studies suggest an increased risk of reinfection with the SARS-CoV-2 Omicron variant compared with previous variants, potentially due to an increased ability to escape immunity specific to older variants, high antigenic divergence of Omicron from earlier virus variants as well as its altered cell entry pathway. The present study sought to investigate epidemiological evidence for differential SARS-CoV-2 reinfection intervals and incidence rates for the Delta versus Omicron variants within Wales. Reinfections in Wales up to February 2022 were defined using genotyping and whole genome sequencing. The median inter-infection intervals for Delta and Omicron were 226 and 192 days, respectively. An incidence rate ratio of 2.17 for reinfection with Omicron compared to Delta was estimated using a conditional Poisson model, which accounted for several factors including sample collection date, age group, area of residence, vaccination and travel status. These findings are consistent with an increased risk of reinfection with the Omicron variant, and highlight the value of monitoring emerging variants that have the potential for causing further waves of cases.