Omicron Variant Partly Evades Pfizer Vaccine Protection; But This Group Remains Safe

A new study from South Africa found that the Omicron variant, first discovered in November, could dull the protection offered by the Pfizer-BioNTech COVID-19 vaccine.

In a study first published online on Tuesday, researchers in South Africa suggested the B.1.1.529 variant could partly evade the power of the Pfizer shots, but noted that booster doses could offer more protection against the new COVID-19 strain.

The researchers also found that participants who had COVID-19 before being vaccinated were well protected against the new variant.

The study used samples taken from six people who received two doses of the Pfizer vaccine without ever being infected with COVID-19 and samples from a different set of six people who had recovered from infection prior to receiving vaccine shots.

The Omicron variant decreased the levels of antibodies in vaccinated participants by 41-fold. However, the researchers noted that the results offer an incomplete picture of how well the vaccines would protect people from COVID-19 hospitalizations and deaths in real life.

"While I think there’s going to be a lot of infection, I’m not sure this is going to translate into systems collapsing," Alex Sigal, a virologist at the Africa Health Research Institute in Durban, South Africa, who led the research, told The New York Times.

Sigal said that the results would likely change as researchers test more COVID-19 samples, adding that there are several factors that affect the antibodies generated by a vaccinated person.

"I thought this news was very positive. I expected worse," Sigal told CNN in a telephone interview. "This is not a variant that has completely escaped. It certainly escapes. It is certainly bad. But it looks to me like there are ways of dealing with it."

The team plans to test more COVID-19 samples from people infected with the Omicron variant and to test them against different vaccines.

Both Pfizer and Moderna have previously announced they were testing their vaccines’ effectiveness against the new COVID-19 variant. The drugmakers also said they are working on producing a vaccine tailored to the variant within the next three months.

The Omicron variant has so far been detected in over 30 countries, including the U.S. where at least 17 states have reported cases of the new variant.