Pfizer says bivalent booster outperforms original vaccine against variants

Pfizer BioNTech COVID-19 vaccine trial

BIO members Pfizer and BioNTech’s Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine “elicits a greater increase in neutralizing antibody titers” than their original COVID-19 vaccine “against these emerging Omicron sublineages,” Pfizer announced last week.

The present study, a phase 2/3 clinical trial, “characterized neutralization activities against new Omicron sublineages BA.4.6, BA.2.75.2, BQ.1.1, and XBB.1 after a 4th dose (following three doses of BNT162b2) of either the original monovalent BNT162b2 or the bivalent BA.4/5 booster” in individuals older than 55, Pfizer said. “One month after a 30-µg booster dose of the Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine, neutralizing antibody titers against emerging Omicron sublineages increased 3.2- to 4.8-fold compared to the companies’ original COVID-19 vaccine,” Pfizer said.

Based on the findings, the bivalent booster “may help to provide improved protection against COVID-19 due to Omicron BA.4 and BA.5 sublineages as well as new sublineages that continue to increase in prevalence,” the release said.

The finding that using the bivalent booster after a fourth dose increased immunity as compared with the monovalent booster, was similar to an earlier study that showed using the bivalent booster as a third dose elicited “4-fold higher BA.4/BA.5-response than the companies’ original COVID-19 vaccine,” Pfizer said.

Pfizer’s booster dose of the Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine, as we previously reported, “has been authorized for emergency use by the U.S. Food and Drug Administration (FDA) for ages 5 years and older.”

The booster was also granted “marketing authorization in the EU by the European Commission for ages 5 years and older.”

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