BNT162b2 and mRNA-1273 COVID-19 vaccine effectiveness against the Delta (B.1.617.2) variant in Qatar

Tang, P.; Hasan, M. R.; Chemaitelly, H.; YASSINE, H. M.; Benslimane, F.; Al Khatib, H. A.; AlMukdad, S.; Coyle, P.; Ayoub, H. H.; Al Kanaani, Z.; Al Kuwari, E.; Jeremijenko, A.; Kaleeckal, A. H.; Latif, A. N.; Shaik, R. M.; Abdul Rahim, H. F.; Nasrallah, G.; Al Kuwari, M. G.; Al Romaihi, H. E.; Butt, A. A.; Al-Thani, M. H.; Al Khal, A.; Bertollini, R.; Abu-Raddad, L. J.

The SARS-CoV-2 Delta (B.1.617.2) variant of concern is expanding globally. Here, we assess real-world effectiveness of the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines against this variant in the population of Qatar, using a matched test-negative, case-control study design. BNT162b2 effectiveness against any Delta infection, symptomatic or asymptomatic, was 64.2% (95% CI: 38.1-80.1%) [≥]14 days after the first dose and before the second dose, but was only 53.5% (95% CI: 43.9-61.4%) [≥]14 days after the second dose, in a population in which a large proportion of fully vaccinated persons received their second dose several months earlier. Corresponding effectiveness measures for mRNA-1273 were 79.0% (95% CI: 58.9-90.1%) and 84.8% (95% CI: 75.9-90.8%), respectively. Effectiveness against any severe, critical, or fatal COVID-19 disease due to Delta was 89.7% (95% CI: 61.0-98.1%) for BNT162b2 and 100.0% (95% CI: 41.2-100.0%) for mRNA-1273, [≥]14 days after the second dose. Both BNT162b2 and mRNA-1273 are highly effective in preventing Delta hospitalization and death, but less so in preventing infection, particularly for BNT162b2.