Scientists in South Africa have found that the omicron Covid version significantly decreases antibody production by BioNTech and Pfizer. But, those who are fully recovered and have received booster shots will probably be protected more from severe illness, according to preliminary research released Tuesday.

Prof. Alex Sigal with the Africa Health Research Institute and a team of scientists tested blood samples of 12 people who’d previously been vaccinated with the Pfizer/BioNTech vaccine, looking specifically at how well antibodies generated by the vaccine can neutralize the new variant – meaning block its ability to infect cells.

The researchers found a 41-fold decrease in their ability to neutralize omicron, as compared to the original viral strain. It was a significant drop from the performance of antibodies against these variants. A preprint of this study has not yet been peer reviewed. The ability of vaccine-induced antibodies to neutralize South Africa’s beta virus was reduced threefold. This suggests that omicron has a better track record in evading protection.

“The results we present here with Omicron show much more extensive escape” than the beta variant, researchers wrote. Previous infection followed by booster vaccination is most likely to raise the level of neutralization and confer protection against severe Omicron disease.

Although the preprint study is not yet peer-reviewed, it has tested 14 samples of plasma from 12 people vaccinated. Six of these were infected. Because of the urgent nature of the pandemic, scientists have made their Covid research public.

Albert Bourla, Pfizer’s CEO, said Friday that the company is capable of developing a vaccine against omicron in March 2022. Bourla stated that it would take several weeks before more data can be gathered on the effectiveness of the vaccines against this variant.

CNBC had heard from the Pfizer CEO that protection offered by its two-dose vaccine was likely to decrease in the wake of the emergence of omicron.

South African scientists found that the omicron attached to the same receptor (ACE2) to infect human lungs cells as the previous versions.

This is an ongoing story. Stay tuned for new updates.