(Reuters Health) – New data from Qatar, where 2.2 million people have received at least two doses of an mRNA vaccine for COVID-19, has confirmed that booster shots protect against symptomatic delta infection but provide less of a shield against getting sick with the omicron variant.
However, the boosters “led to strong protection against COVID-19-related hospitalization and death,” researchers reported online in The New England Journal of Medicine.
Overall, nearly 374,000 people received a booster dose.
For Pfizer’s vaccine BNT162B2, the efficacy of the booster against a symptomatic Delta infection was 86.1%.
Booster efficacy was 49.4% against a symptomatic omicron infection.
Protection against hospitalization or death was 76.5%.
Among the recipients of Moderna’s mRNA-1273 vaccine, booster efficacy was 86.1% against symptomatic Delta infection after 35 days of follow-up, and 47.3% against symptomatic Omicron.
“The estimates of effectiveness of the BNT162b2 and mRNA-1273 vaccines against the Delta and Omicron variants are broadly consistent with the growing evidence of the effectiveness of mRNA vaccines against these variants in other countries,” said the team led by Laith J. Abu Raddad of Weill Cornell Medicine – Qatar.
“Given future waves of SARS-CoV-2 infections that may be driven by new variants, these findings may suggest the need for the development of a new generation of vaccines that target a broad range of variants to confront virus evolution, rather than a continued strategy of repeated boosters with existing vaccines,” they said.
Weill Cornell Medicine – Qatar funded the study
SOURCE: https://bit.ly/35Zp71D The New England Journal of Medicine, online March 9, 2022.
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