The trial plans to study the safety and tolerability of the vaccine in over 1400 participants.
On 25 January, Pfizer and BioNTech announced the launch of their clinical trial to test a new version of their already approved vaccine which targets Omicron. The variant has been successful at eluding the protection provided by the two-dose vaccine. The trail will use participants from the United States to test the immune response elicited by the Omicron-targeted vaccine. Unvaccinated people will receive a three-shot regimen while fully vaccinated people will receive the shot as a booster. The companies are also testing a fourth dose of the current vaccine against a fourth dose of the Omicron-targeted vaccine in participants who received the booster dose of the Pfizer/BioNTech vaccine three to six months earlier. The tolerability and safety of the vaccine will be studied in over 1400 participants.
Kathrin Jansen, Pfizer’s head of vaccine research and development stated, "While current research and real-world data show that boosters continue to provide a high level of protection against severe disease and hospitalization with Omicron, we recognize the need to be prepared in the event this protection wanes over time and to potentially help address Omicron and new variants in the future." The U.S. Centres for Disease Control and Prevention stated that a booster shot of an mRNA vaccine such as Pfizer/BioNTech provides 90% protection against hospitalizations. Several countries have begun offering additional booster shots to their residents. Based on the clinical trial data required from the regulatory bodies, the companies may not be able to realise a plan to launch the vaccine by the end of the first quarter.