A small study in South Africa shows that the omicron variant can partially evade protection from two doses of Pfizer Inc (NYSE:PFE) / BioNTech SE's (NASDAQ) COVID-19 vaccine. But the study did show that blood from people who had received two doses of the vaccine and had a prior infection were primarily able to neutralize the variant, thus suggesting booster doses of the vaccine could help to fend off the infection.
What Happened: Researchers at the Africa Health Research Institute in Durban, South Africa, found omicron resulted in a 41-fold reduction in levels of neutralizing antibodies after two doses of Pfizer/BioNTech vaccine.
Alex Sigal, a professor at the institute, said on Twitter that there was "a very large drop" in the neutralization of the omicron variant relative to an earlier strain of COVID-19.
The team tested 14 blood plasma samples collected from 12 previously vaccinated people with the Pfizer/BioNTech vaccine, 6 of whom were previously infected.
The preliminary data in the manuscript has not yet been peer-reviewed.
Why It Matters: If needed, Pfizer CEO Albert Bourla said that the company could develop a vaccine that targets omicron by March 2022.
Bourla said it would take a few weeks to get more definitive data on whether the current vaccines provide enough protection against the variant.
In addition to the South African study, the companies also posted data from the initial laboratory study demonstrating that three doses of Pfizer-BioNTech COVID-19 vaccine neutralized the omicron variant.
Sera obtained from people one month after receiving the booster shot neutralized the omicron variant to levels comparable to the wild-type spike protein after two doses.
But the data did exhibit, on average, more than a 25-fold reduction in neutralization titers against the omicron variant compared to wild-type.
According to the companies, as most epitopes targeted by vaccine-induced T cells are not affected by the mutations in omicron, the companies believe that vaccinated individuals may still be protected against severe forms of the disease.
Price Action: BNTX shares are down 1.38% at $298.50, PFE stock is up 0.75% at $52.11 during the premarket session on the last check Wednesday.