Pfizer COVID booster may protect against omicron variant infection — two doses may not

New laboratory data shows a Pfizer-BioNTech COVID-19 booster shot may help protect you against the omicron coronavirus variant that early research shows may be more contagious and capable of evading vaccines, according to the companies.

Experiments on blood samples from people who received a Pfizer booster a month ago found antibody levels increased 25-fold against omicron, similar to levels seen after two doses against the original version of the coronavirus.

Blood from people who only received two doses of the vaccine, however, experienced a 25-fold reduction in antibody levels against the omicron variant, on average, suggesting two shots may not protect against omicron infection, the companies said in a news release posted Wednesday, Dec. 8.

What’s important to note is the possibility that two doses of the Pfizer vaccine may still protect against severe COVID-19, including hospitalization and death. Early data shows other parts of the immune system that have been primed by the vaccine “are not affected by the mutations in the omicron variant.”

Because early data is coming from laboratory studies, scientists won’t know the exact effects the omicron variant has on COVID-19 vaccines’ effectiveness in real world settings. Experts around the globe are quickly collecting data to learn more.

“Although two doses of the vaccine may still offer protection against severe disease caused by the omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” Albert Bourla, chairman and chief executive officer of Pfizer, said in the news release. “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 new data aligns with research released Tuesday, Dec. 7 from the Africa Health Research Institute that found a 40-fold reduction in Pfizer vaccine antibodies, NBC News reported.

Pfizer and BioNTech started developing an omicron-specific coronavirus vaccine on Nov. 25, a day after researchers in South Africa first reported the variant to the World Health Organization. The revised vaccine would be available by March “in the event that an adaptation is needed to further increase the level and duration of protection,” the developers said.

Moderna CEO Stéphane Bancel said he expects the company’s COVID-19 vaccine to also lose some of its effectiveness when put up against omicron, citing the large number of mutations on the variant’s spike protein — which the coronavirus uses to enter human cells.

Federal health officials confirmed the first omicron case in the U.S. on Dec. 1, in a fully vaccinated California resident who recently returned from South Africa. The variant has since been detected in over 50 countries and 19 states, “and we expect that number to continue to increase,” Centers for Disease Control and Prevention Director Dr. Rochelle Walensky said during a White House COVID-19 briefing on Tuesday, Dec. 7.

Nearly 200 million people in the U.S. are fully vaccinated against COVID-19 as of Dec. 7, a CDC tracker shows. And nearly 50 million have received booster shots.