Bivalent mRNA-1273.214 vaccine effectiveness against SARS-CoV-2 omicron XBB* infections
Hiam Chemaitelly, Houssein H. Ayoub, Sawsan AlMukdad, Jeremy Samuel Faust, Patrick Tang, Peter Coyle, Hadi M. Yassine, Asmaa A. Al Thani, Hebah A. Al-Khatib, Mohammad R. Hasan, Zaina Al Kanaani, Einas Al‐Kuwari, Andrew Jeremijenko, Anvar Hassan Kaleeckal, Ali Nizar Latif, Riyazuddin Mohammad Shaik, Hanan F. Abdul Rahim, Gheyath K. Nasrallah, Mohamed Ghaith Al‐Kuwari, Adeel A. Butt, Hamad Eid Al‐Romaihi, Mohamed H. Al‐Thani, Abdullatif Al‐Khal, Roberto Bertollini, Laith J. Abu‐Raddad
Abstract
Effectiveness of the 50-μg mRNA-1273.214 bivalent vaccine against SARS-CoV-2 infection was modest at 25% in a matched, retrospective, cohort study in Qatar comparing infection incidence in the bivalent cohort to that in the national no-recent-vaccination resident cohort. XBB* immune evasion, immune imprinting effects, or both, may explain findings.