Initial studies show two doses of the Pfizer vaccine may not give enough protection against the variant, but three doses are able to neutralize it, the company says
Samples from people who had two doses of the Covid-19 vaccine saw, on average, a more than 25-fold reduction in neutralization ability against the Omicron variant than the earlier virus, “indicating that two doses of BNT162b2 may not be sufficient to protect against infection with the Omicron variant,” the companies said.
The companies said two doses may still provide protection against severe disease.
“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,” 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 initial lab studies used serum from blood from individuals who received two or three doses of the Pfizer/BioNTech Covid-19 vaccine. The sera was collected from subjects three weeks after their second dose, or one month after a third dose.
Pfizer and BioNTech are continuing to develop a variant-specific vaccine for Omicron and say it will be available by March, if it’s needed.
The data released Wednesday has not been peer-reviewed or published.
Researchers in South Africa on Tuesday released a preprint study that showed the Omicron coronavirus variant partly escapes the protection offered by the Pfizer vaccine. The study showed people who have been previously infected and then vaccinated are likely to be well protected, and Alex Sigal of the Africa Health Research Institute in Durban, who led the study team, told CNN that boosters are also likely to protect people.
“My impression is if you get a booster you are protected, especially against severe disease,” Sigal said.
