New Corona variant
Three doses of Biontech vaccine, according to study, effective against Omikron
According to the pharmaceutical company Pfizer, a booster vaccination with the corona vaccine from Pfizer and Biontech can protect against the Omikron virus variant.
© Pavlo Gonchar / SOPA Images via ZUMA Press Wire / DPA
A booster vaccination with the corona vaccine from Pfizer and Biontech can protect against the virus variant Omikron, according to the US pharmaceutical manufacturer. However, a study by the virologist Sandra Cisek comes to a different conclusion.
According to initial studies, the vaccine from Pfizer and Biontech is effective against the omicron variant of the coronavirus after three doses. The two manufacturers announced this on Wednesday, citing their own study. “Preliminary data suggest that a third dose elicits similar levels of neutralizing antibodies to Omikron as seen after two doses against the wild-type and other variants that occurred before Omikron,” the statement said.
In the opinion of the manufacturer, two vaccine doses “do not offer sufficient protection against infection with the Omikron variant”. However, the companies assume that at least protection against the course of serious illness is guaranteed.
Omikron: Adapted vaccine by March
“Ensuring that as many people as possible are fully vaccinated with the two-dose series and the booster dose remains the best strategy to prevent the spread of Covid-19,” said Pfizer CEO Albert Bourla. Biontech CEO Ugur Sahin called for “large-scale vaccination and refreshment campaigns around the world” in order to “get through the winter” protected.
Pfizer and Biontech expect that they will be able to produce a vaccine adapted to the Omikron variant by the end of March, “should the vaccine need to be adapted for higher and longer-lasting protection.”
Virologist Ciesek: Vaccines generate weaker immune responses against Omikron
Virologist Sandra Ciesek comes to a different conclusion. Initial laboratory tests on the effect of corona vaccines against Omikron therefore indicated a weaker defense reaction against the new variant. The virologist from the University Hospital Frankfurt published the first results on Twitter on Wednesday, which show a significantly reduced antibody response to the new variant. “The data confirm that the development of a vaccine adapted to Omikron makes sense,” wrote Ciesek. South African experts had already presented similar data the day before, according to which the antibody response in people vaccinated against Omikron is weaker.
However, Ciesek also pointed out that it is not possible to read from their evaluation whether vaccinated people are protected from a severe course at Omikron. Because the immune response is not only based on antibodies, but also, for example, on T cells.
In order to examine the effect of a vaccine against a certain variant of Sars-CoV-2, researchers usually do so-called neutralization tests. It is checked how many antibodies a vaccinated person has in the blood that can reach the virus variant and thus switch it off. The actual protection of vaccinated persons cannot be determined with this, however, clinical studies with thousands of test persons or evaluations of the ongoing infection process are required.
Reduction of the immune response even with booster vaccinations
According to Ciesek, the antibody response against Omikron is drastically reduced compared to the Delta variant – there is also a reduction in people with a booster vaccination. The data have not yet been reviewed by specialist colleagues and have not been published in a specialist magazine.
Researchers at the Africa Health Research Institute in South Africa published preliminary data on Tuesday on the effectiveness of the Biontech / Pfizer vaccine against Omikron. According to a communication, the results suggest that the virus variant escapes the antibody response of two-fold vaccinees. In vaccinated persons who were also infected, however, a considerable antibody response was measurable. These results have not yet been published in a specialist journal either.
The omicron variant was discovered by scientists in South Africa at the end of November. Since then it has been found in dozen of countries, including Germany. It has 50 mutations compared to the original virus, 32 of them in the so-called spike protein, with which the coronavirus docks on the host cell.