Protection against the Omicron Variant from Previous SARS-CoV-2 Infection
Heba N. Altarawneh, Hiam Chemaitelly, Mohammad R. Hasan, Houssein H. Ayoub, Suelen Qassim, Sawsan AlMukdad, Peter Coyle, Hadi M. Yassine, Hebah A. Al-Khatib, Fatiha M. Benslimane, 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, Patrick Tang, Laith J. Abu-Raddad
Abstract
Natural infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicits strong protection against reinfection with the B.1.1.7 (alpha),1,2 B.1.351 (beta),1 and B.1.617.2 (delta)3 variants. However, the B.1.1.529 (omicron) variant harbors multiple mutations that can mediate immune evasion. We estimated the effectiveness of previous infection in preventing symptomatic new cases caused by omicron and other SARS-CoV-2 variants in Qatar. In this study, we extracted data regarding coronavirus disease 2019 (Covid-19) laboratory testing, vaccination, clinical infection data, and related demographic details from the national SARS-CoV-2 databases, which include all results of polymerase-chain-reaction (PCR) testing, vaccinations, and hospitalizations and deaths for Covid-19 in Qatar since the start of the pandemic.