United States: Pfizer has started a trial comparing its initial COVID-19 vaccine to dosages tailored to the highly contagious omicron variant. The trial was announced on Tuesday by Pfizer and its partner BioNTech.

COVID-19 vaccine manufacturers have been upgrading their vaccines to better match omicron in case global health authorities deem it necessary. Despite the fact that omicron is more likely than earlier variations to induce infection in persons who have been vaccinated, it is not obvious whether a change to the vaccine recipe is required. The initial vaccines are still effective in preventing serious illness and death. Adding a booster dosage increases that protection and boosts the odds of avoiding a milder infection, according to studies conducted in the United States and abroad.

In a statement, Kathrin Jansen, Pfizer's vaccine research leader, said, "We realise the need to be prepared in the event that this protection wanes over time and to potentially help address omicron and new variations in the future."

Up to 1,420 healthy persons, ages 18 to 55, will be included in the new U.S. research to test the updated omicron-based vaccines as a booster or primary vaccination. Researchers will compare the safety of the modified vaccination to the original injections and see how it affects the immune system.

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