Now with Omicron’s even more transmissible relatives spreading widely,the United States’ Food and Drug Administration is considering ordering a recipe change for the vaccines made by both Pfizer and rival Moderna in hopes that modified boosters could better protect against another COVID-19 surge expected in the Northern Hemisphere’s autumn and winter.
Pfizer and its partner BioNTech studied two different ways of updating their shots – targeting just Omicron,or a combination booster that adds Omicron protection to the original vaccine. They also tested whether to keep the current standard dosage – 30 micrograms – or to double the shots’ strength.
In a study of more than 1200 middle-aged and older adults who’d already had three vaccine doses,Pfizer said both booster approaches spurred a substantial jump in Omicron-fighting antibodies.
“Based on these data,we believe we have two very strong Omicron-adapted candidates,” Pfizer CEO Albert Bourla said in a statement.
Pfizer’s Omicron-only booster sparked the strongest immune response against that variant.
But many experts say combination shots may be the best approach because they would retain the proven benefits of the original COVID-19 vaccine while adding new protection against Omicron. And Pfizer said a month after people received its combo shot,they had a 9 to 11-fold increase in Omicron-fighting antibodies. That’s more than 1.5 times better than another dose of the original vaccine.