Omicron subvariants linked to reinfectionsA new study based on COVID-19 patients in France shows high reinfection rates among people with different Omicron subvariants, including BA.1, BA.2, and BA.5.
The study is published as a research letter in Emerging Infectious Diseases.The research group conducting this study, from Aix Marseille University, previously found reinfection rates were 6-fold higher during the Omicron surge than in previous variant surges.
In this study, the authors used a computerized alert system that identified positive case samples with primary Omicron BA.1 or BA.2 subvariant infections followed by reinfection with any Omicron subvariant.They found 188 (0.7%) cases of reinfection out of 27,972 patient samples that tested positive for Omicron from Nov 28, 2021, to Jul 22, 2022.
Of the 188 cases, 181 were first infected with the Omicron BA.1 subvariant. Of those, 82 patients were reinfected with Omicron BA.2, 14 were infected with Omicron BA.4, 84 with Omicron BA.5, and 1 with a BA.1 and BA.2 recombinant subvariant (XAC recombinant lineage).The median age of patients was 32, and 70% were women.