Pfizer, BioNTech data support new Covid booster’s advantage over original vaccine
Pfizer and BioNTech on Nov. 4 released updated clinical trial results for their omicron-adapted booster shot for COVID-19. The new data, which detail immune responses after one month, follow earlier data evaluating the vaccine after seven days.
According to Pfizer and BioNTech, booster vaccination in adults between 18 and 55 years old raised antibody levels against the BA.4 and BA.5 omicron variants by nearly 10-fold compared to pre-booster levels. The additional shot raised antibody levels more than 13-fold in adults over 55 years old, the companies said.
Uptake of the boosters remain slow and the companies don’t yet have evidence showing relative effectiveness between their new shot and the old one on outcomes like infection and disease. New omicron substrains, meanwhile, are gaining prevalence, a development that Pfizer and BioNTech said they were monitoring.
Pfizer and BioNTech’s updated booster was quickly made ready in time for a campaign by the Biden administration to encourage vaccination before the flu and winter season. The Food and Drug Administration’s authorization came based on limited preclinical data, as well as trial results from a similar, but different reformulation of the companies’ original shot.
Pfizer and BioNTech initially shared seven-day immune response data in mid-October, but they did not reveal specific data.
The latest results provide more details supporting the added protection offered by the new booster. In adults over the age of 55, the bivalent booster increased omicron antibodies by substantially more than Pfizer and BioNTech’s original vaccine, which drove a 2.9-fold increase in antibody levels.
However, more data are still needed, such as to compare the relative increase in antibodies in younger adults, as well as in children. Other smaller studies have found little comparative advantage between the new booster and the original shot, although the FDA has cautioned they may be too small to support any conclusions.
The additional data could help encourage more people to get the booster. But since its authorization by the FDA in August, only 8.4% of those eligible for the shot have received it.
The slow uptake has made for greater uncertainty around future sales of both Pfizer’s and Moderna’s COVID-19 vaccines, which have earned the companies tens of billions of dollars in 2022. The U.S. government no longer plans to buy the shots in bulk in 2023, thereby shifting sales onto the private market. In response, both companies are considering a higher price, although executives have emphasized that people who are insured wouldn’t have to pay out of pocket.
Meanwhile, the Centers for Disease Control and Prevention is monitoring omicron’s prevalence in new COVID-19 cases, as well as the rise of several subvariants. According to recent estimates from the agency, the substrains BQ.1, BF.7 and BQ1.1 are gaining ground, with BQ.1 accounting for about 14% of new cases.
“In the next step and as part of our science-based approach we will continue to evaluate the cross-neutralization of the adapted vaccine against new variants and sublineages,” said BioNTech CEO, Urgur Sahin, in the companies’ Nov. 4 statement. “Our goal is to provide broader immunity against COVID-19 caused by SARS-CoV-2, including Omicron and other circulating strains.”
Pfizer and BioNTech will continue to evaluate the immunogenicity and safety of the bivalent shot in children between the ages of six months and 11 years in a Phase 1/2/3 trial.