Pfizer says new booster boosts anti-omicron antibodies
“Based on all the data we now have in hand, we have confidence in bivalent covid-19 vaccines and their ability to create better protection against covid-19, including these currently circulating variants, than the original vaccine wouldn’t have,” Peter Marks, director of the Food and Drug Administration’s Center for Biologics Evaluation and Research, said. He urged the public to consider getting the updated recall before Thanksgiving.
Pfizer presented the data in a press release, and it has not been peer reviewed or published.
The press release does not directly address a concern raised by little studies last week that immune evasion variants which have recently emerged and are rapidly gaining the upper hand seem to be much better at evading the anti-virus antibodies generated by the booster.
One of the most threatening new variants gaining traction in the United States, BQ.1.1, is linked to BA.5, a component of the new recall, so Marks said he hopes the bivalent vaccine will hold up in a certain extent.
The new data also adds to, but does not resolve, an ongoing scientific debate about how much better new boosters are than old boosters. This remains a critical issue for scientists to address as they design a long-term vaccine strategy against the virus. But that technical debate is largely separated from the public health question of whether to get a booster, which Pfizer data shows provides a significant boost to antibodies, a key line of immune defense.
In adults over 55, the new booster elicited a stronger immune response against BA.4 and BA.5 than the original booster, although it is unclear whether the difference, measured in tests laboratory, would provide a significant difference in the way people were. protected. It was unclear whether the new vaccine caused a stronger response in young adults than the old booster, as these data were not included.
The new booster triggered a four-fold increase in omicron-blocking antibody levels against the BA.4/BA.5 version of omicron compared to the old booster in the elderly. This is a measurable biological difference, but scientists have differing opinions as to whether it will make a difference in how likely people are to get sick.
Some scientists have argued that a 10-fold difference would likely be clinically significant. Marks said a two- to four-fold increase in antibodies could better protect people against symptomatic infections and increase the durability of protection because antibodies, which decay over time, would recoil from a higher initial level. raised.
Pfizer did not include similar data to show benefit of the new vaccine in people aged 18 to 55, and the company did not respond to questions about why this data was not presented.
Bivalent boosters clearly boost immunity and are an essential tool for a possible winter surge, but they have also raised questions about how to design the best vaccine strategy for a population that has a varied history of infection and vaccination.
“We must now seriously rethink the national policy of vaccination against covid. Chasing variants with booster redesigns is clearly not a sustainable solution,” said John P. Moore, professor of microbiology and immunology at Weill Cornell Medicine, who criticized the formulation chosen for the booster-specific booster. ‘omicron.
Adoption of updated boosters has been disappointing so far. According to Centers for Disaster Control and Prevention, only 8.6% of people aged 18 and over received a new reminder. The low booster coverage is particularly concerning among adults aged 65 and over, who are at increased risk of complications from the coronavirus due to their age. A fifth of people in this age group received the new reminders.