Patterns in Repeat Reinfections: Pre and Post Omicron Emergence

• DOI: 10.1101/2023.06.29.23292041
• Publication Date: 2023-07-02T00:00:15Z
• Authors: Hiam Chemaitelly; Houssein H. Ayoub; Patrick Tang; Peter Coyle; Hadi M. Yassine; Asmaa A. Al Thani; Mohammad R. Hasan; Zaina Al-Kanaani; Einas Al-Kuwari; Andrew Jeremijenko; Anvar H. Kaleeckal; Ali N. Latif; Riyazuddin M. Shaik; Hanan F. Abdul-Rahim; Gheyath K. Nasrallah; Mohamed G. Al-Kuwari; Adeel A. Butt; Hamad E. Al-Romaihi; Mohamed H. Al-Thani; Abdullatif Al-Khal; Roberto Bertollini; Laith J. Abu-Raddad

Abstract Our understanding of SARS-CoV-2 reinfection patterns remains limited. We conducted a longitudinal study using Qatar’s national data from February 28, 2020 to June 11, 2023 investigate incidence reinfections both prior and after omicron emergence. The latter analysis excluded individuals with pre-omicron infections. Before introduction, the proportion incident infections classified as gradually increased but remained minimal, reaching 1.8% just before emerged. During first wave, this reached 9.0%, 5-fold increase. After conclusion identified rapidly increased, 43.3% towards end study. In era, total 3,131 were documented, which 99.6% 0.4% second reinfections. Meanwhile, 20,962 documented an primary infection 99.0% reinfections, 1.0% 0.01% third Reinfections rare omicron’s emergence became widespread during including among previously infected omicron. findings may indicate accelerated viral evolution in era aimed at evading population immunity, minimal impact on COVID-19 severity, or potentially suggest immune imprinting effects that require further investigation.