Scientists in South Africa say the new and rapidly spreading omicron variant of the coronavirus that causes COVID-19 is partly able to evade antibodies produced by either a previous infection or vaccination.

The results were found in laboratory tests conducted at the Africa Health Research Institute in Durban on blood samples of 12 people who had been fully vaccinated with the two-dose Pfizer vaccine. The researchers discovered a 41-fold decrease in the levels of neutralizing antibodies against omicron, a much more extensive decrease than other variants in similar experiments.

The samples were separated between those from six uninfected vaccinated people and six people who had been infected with COVID-19 before getting vaccinated. The researchers discovered that the samples from the second group produced stronger antibodies than those of the first group.

Alex Sigal, the lead researcher, says the results show that vaccines and vaccine booster shots are still effective against omicron. The study, which was released online Tuesday, has not been published in a peer-reviewed scientific journal.

In a similar development, Pfizer and German-based BioNTech, the co-developer of its COVID-19 vaccine, said Wednesday that preliminary laboratory studies showed the two-dose vaccine was effective against the omicron variant after it was administered as a booster.

The companies said the samples of individuals who received the initial two-dose regimen showed a 25-fold decrease in antibodies against omicron compared to a so-called “wild-type” version of the coronavirus, while samples from people who received the booster shot showed the extra dose increased the antibodies by the same amount.

Pfizer and BioNTech are developing a new version of their COVID-19 vaccine specifically to combat the new omicron variant.

In other developments, British drugmaker GlaxoSmithKline says further studies of its experimental COVID-19 antibody treatment is effective against all 37 identified mutations of the omicron variant. Earlier studies showed that the drug, called sotrovimab, was effective against a key mutation in omicron’s spike protein, the part of the virus that binds to cells in our bodies.

GSK is developing sotrovimab in collaboration with U.S.-based drugmaker Vir Biotechnology. The results of the study have not been peer-reviewed.

Source: Voice of America