The study was announced Tuesday by Pfizer and BioNTech, the company's partner.
In case of global health authorities deciding that the change is necessary, COVID-19 vaccine-makers have been updating shots to match omicron better.
Omicron is more likely to infect people than other variants, even if they have been vaccinated. However, it is not clear if a change to vaccine recipes will be required. Regulators are currently weighing the following issues: Omicron is already showing signs of waning in some areas that are facing an omicron surge. It's not yet clear if the next variant will look like omicron, or completely different.
The original vaccines offer excellent protection against severe illness, and even death. Research in the U.S. has shown that adding a booster dose increases that protection and helps to avoid milder infections.
Kathrin Jansen (Pfizer's chief vaccine researcher), stated in a statement that "We recognize the necessity to be prepared in case this protection wanes over the time and to possibly help address omicron or new variants in future."
Up to 1,420 volunteers aged 18-55 will participate in the new U.S. study to evaluate the effectiveness of updated omicron shots as boosters or primary vaccines. Researchers will compare the modified vaccine to determine its safety and boost the immune system.
The full study will take several months because volunteers receive multiple vaccine doses and researchers need to measure the virus-fighting antibodies' levels after an omicron-adapted dosage versus the regular booster.
CNBC reported that Pfizer's CEO stated earlier this month that they could have some omicron-matched dosages available as soon as March. However, the company doesn't guarantee that these doses will be made available to the public by doing "at-risk manufacturing". Pfizer and other vaccine manufacturers have also tested and brewed experimental doses to match the previous variants. While these changes weren't necessary, they provided valuable practice in tweaking the recipe.
One group of 600 volunteers will be given one or two booster shots of the omicron-based vaccine. The new study involves about 600 people who have received the current Pfizer vaccine two times in the past three to six months. Another 600 people who have received three doses of the Pfizer vaccination will receive a fourth dose. They can choose to get the regular vaccine or the omicron matched vaccine.
Some unvaccinated participants will also be enrolled in the study, who will receive three doses each of the omicron vaccine.
Pfizer intends to produce 4 Billion vaccine doses by 2022. The company said Tuesday that the amount will not change if there is an omicron-adapted version.