Pfizer and partner BioNTech are enrolling nearly 1,500 healthy adults to test a reformulated COVID-19 vaccine for effectiveness against the omicron variant.
While the World Health Organization has not said new vaccines are needed, the companies said they want to prepare in case health regulators determine the variant requires different shots.
Pfizer expects to produce 4 billion doses of its COVID-19 vaccine in 2022 whether or not it has to pivot to a different formula.
How will the trial work? The study will look at three groups. Some who received two Pfizer doses three to six months ago will get one or two of the new shots as boosters. The next group, which has received three Pfizer shots, will be given one additional booster of either the current formula or the new one. The remaining unvaccinated volunteers will receive three doses of the omicron version.
Although the latest variant tends to evade current doses due to its high number of mutations, international regulators are holding off on recommending different vaccines.
Omicron cases are already waning, and health experts say there could be a future variant that evades Pfizer’s vaccine.
This story originally appeared in WORLD. © 2022, reprinted with permission. All rights reserved.