Two doses of Pfizer-BioNTech’s coronavirus vaccine may not offer enough protection against the Omicron variant but a booster shot increased antibody defenses 25-fold, the companies said today, citing preliminary laboratory results.
“It’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” Pfizer Chairman and CEO Albert Bourla said in a statement. “Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of Covid-19.”
The early data from the company study has not been peer-reviewed.
The companies said a third dose appears to provide a similar number of antibodies as a two-dose series against the original virus and other variants. People who have two shots of the vaccine may still be protected against severe cases, they added.
The companies on Nov. 25 began developing an Omicron-specific vaccine and said Wednesday that the work will continue in case the shot is needed to increase the level and duration of protection against Omicron. First batches of the Omicron-based vaccine can be produced and are planned to be ready for deliveries within 100 days, pending regulatory approval, Pfizer and BioNTech said.
The companies said they “have high confidence” they can deliver an Omicron-based vaccine in March 2022, if needed, and that it won’t affect plans to produce 4 billion doses of vaccines next year.
South African researchers this week reported that studies suggest the Omicron variant can partiallly evade protection from two Pfizer-BioNTech shots — but that people who were previously infected and had received two doses were able to largely neutralize the variant.
David Lim contributed to this report.