The newly authorized bivalent, omicron-focused boosters elicited a response similar to the fourth dose of the original COVID-19 vaccine formula, according to a preprint study posted Oct. 24.
About a month after receiving the booster shot, study participants who got the omicron subvariant BA.4/BA.5-focused vaccine had "similar neutralizing antibody titers as those receiving a fourth monovalent mRNA vaccine." All variants and subvariants were tested.
The study evaluated Pfizer's and Moderna's tweaked boosters, which were authorized Sept. 1. In recent weeks, the vaccine-makers have reported positive results showing their shots are safe and effective.
The researchers, who are from New York's Columbia University and Ann Arbor's University of Michigan, concluded that follow-up studies are needed to determine whether "antibody responses will deviate in time, including the impact of a second bivalent booster."
More bivalent boosters could be on the horizon. Director of the National Institute of Allergy and Infectious Diseases Anthony Fauci, MD, said in early September that COVID-19 vaccine jabs could become as regular as flu shots — but that could mean a universal vaccine, which is still in development, or a new modified vaccine every year.