According to a study published in the journal The Lancet Infectious Diseases, vulnerable people aged 65 and over who have received the Pfizer bivalent mRNA vaccine booster dose showed a 72% lower risk of COVID-related hospitalization and a 68% lower risk of COVID-related death.

Bivalent mRNA vaccines were developed to enhance vaccine-induced immunity against the omicron variation and subsequent subvariants. These vaccinations included components from both the initial wild-type COVID strain and an updated component from the Omicron strain. Study co-author, Mr. Ronen Arbel, of Clalit Health Services, Tel Aviv, Israel, stated that the study findings highlighted the importance of new types of vaccines containing different variants of SARS-CoV-2, which are likely to induce broader immune responses and provide enhanced protection against severe outcomes.

The researchers performed a retrospective cohort study to evaluate the effectiveness of the bivalent vaccine, which included 5,69,519 eligible participants. Overall, 1,34,215, or 24%, of the participants received a bivalent mRNA booster vaccination during the study period.The findings of the study showed that hospitalization due to COVID-19 occurred in 32 participants who received a bivalent mRNA booster vaccination and 541 participants who did not receive a bivalent booster vaccination.

According to analysis, this translated to a 72% lower risk of hospitalization for those who received the bivalent booster. The adjusted COVID-related hospitalization risk was reported to be 0.035% in the bivalent booster patients, compared to 0.124% in the non-recipients. The adjusted COVID-19-related death risk in those who received the bivalent booster was found to have been reduced to 0.013% from 0.040% in participants who had received the bivalent jab. 

(Source: https://www.tribuneindia.com/news/health/pfizer-bivalent-vaccine-reduces-covid-related-death-risk-by-68-pc-in-older-people-reveals-study-497330)