Pfizer-BioNTechEarly data from a Pfizer-BioNTech (NYSE:PFE/Nasdaq:BNTX) Phase 2/3 study (NCT05472038) indicate that their updated omicron BA.4/BA.5-adapted bivalent COVID-19 booster works as intended. 

After drawing sera from booster recipients seven days after administration, investigators concluded that a single 30-µg booster dose increased omicron BA.4/BA.5 neutralizing antibody levels. In addition, they note that the updated vaccine potentially offers more robust protection against those omicron sub-lineages than the original vaccine in adults. 

The updated vaccine also appeared to be well tolerated, with a safety profile similar to the companies’ first COVID-19 vaccine. 

Pfizer and BioNTech will present additional data on the bivalent vaccine one month after administration in the coming weeks. 

The study broke participants into two age groups, with the first aged 18 to 55 years old and the second group older than 55. There were 40 volunteers in each age group. 

Only about one-third of U.S. adults have received a bivalent COVID-19 booster.

“While we expect more mature immune response data from the clinical trial of our omicron BA.4/BA.5-adapted bivalent vaccine in the coming weeks, we are pleased to see encouraging responses just one week after vaccination in younger and older adults,” said Pfizer CEO Dr. Albert Bourla, in a news release. “These early data suggest that our bivalent vaccine is anticipated to provide better protection against currently circulating variants than the original vaccine and potentially help to curb future surges in cases this winter.”

In the recent research on the updated COVID-19 booster, investigators used a SARS-CoV-2 live virus fluorescent focus reduction neutralization test (FFRNT) assay. 

Participants in the study had received three earlier doses of the original BNT162b2 COVID-19 vaccine. 

The FDA has authorized the updated vaccine booster for adults and children down to five years old

Pfizer shares were up 2.28% to $42.99 in mid-day trading. BioNTech saw its stock tick up 2.39% to $139.92.