Frankfurt After two doses, the Covid-19 vaccine from Biontech and Pfizer offers significantly less protection against infections with the new Omicron variant than against the previously circulating coronavirus variants. The two manufacturers confirmed this on Wednesday based on their own laboratory tests.
However, Biontech and Pfizer assume that an additional third, so-called booster vaccination with the previous vaccine can significantly increase the protective effect against Omikron. According to preliminary data, the concentration of neutralizing antibodies against Omikron will be increased to a level similar to that after two vaccinations against the conventional Covid variants.
“Our first preliminary data suggest that a third dose, even with the Omikron variant, still offers sufficient protection against Covid diseases of any severity,” explains Biontech boss Ugur Sahin. “Large-scale vaccination and refresher campaigns around the world could help us better protect people around the world and get through the winter.”
Investors reacted positively to the reports from the two companies. The Biontech share recovered from initial losses and was up more than two percent in the early afternoon. The stock market valuation increased to 64 billion euros. The shares of Moderna and Pfizer were also quoted more firmly in the pre-trading period.
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In the conventional double vaccination, the antibody concentrations against Omikron are, according to analyzes by Biontech and Pfizer, 25 times lower than against the previous virus variants. However, the companies point out that this vaccination should still offer protection against serious Covid diseases even with Omikron.
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The basis for this is the expectation that the cellular immune protection will be less reduced by the mutations of the omicron variant than the effect of antibodies. Because around 80 percent of the protein structures on the spike protein of the virus, which are typically recognized by T cells of the immune system, are not affected by the mutations, according to the Biontech scientists.
Biontech and Pfizer are also pushing ahead with work on an mRNA vaccine specially tailored to Omikron. It is assumed that this will be available in March if this should be necessary to increase the strength and duration of vaccination protection, it said on Wednesday. This will not change the planned production capacity of four billion cans in the coming year.
The Omikron variant, which was first discovered in South Africa in mid-November and is now spreading worldwide, has triggered an alarm. Scientists assume that due to a particularly high number of mutations in the spike protein, it could be significantly more contagious and can easily overcome the existing vaccination protection. This would involve the risk of very rapid spread.
Laboratory tests provide evidence of a lack of effectiveness
This assessment was supported by initial laboratory tests. Scientists in South Africa tested the blood serum of twelve vaccinated and, in some cases, pre-infected people for its effect against the omicron variant and came to the conclusion that the antibody concentration was reduced by a factor of 41. The neutralization of the Omikron variant “decreased very much” compared to an earlier Covid strain, said Alex Sigal, professor at the Africa Health Research Institute in South Africa.
The Omikron variant was still able to neutralize the blood of five of the six people who had been vaccinated and previously infected with Covid-19. The results are still better than expected, explained Sigal: “The more antibodies you have, the greater the chance that you will be protected from Omikron.”
The data that virologist Sandra Ciesek from the Frankfurt University Hospital published on Wednesday is even more threatening. According to this, the neutralization of omicron viruses six months after a double vaccination with the vaccines from Biontech, Moderna or the combination of Astra-Zeneca and Biontech were both at zero percent.
Ciesek spoke on twitter the neutralizing effect of the antibodies is reduced by up to 37 times compared to the delta variant. Even three months after a booster vaccination, the neutralizing effect with Omeka was only 25 percent compared to 95 percent with the Delta variant. The data strengthened the view that “the development of a vaccine adapted to Omikron makes sense,” wrote the virologist on Twitter.
The virologist Christian Drosten from the Charité spoke of very important data and commented on Twitter: “Doesn’t look good for a double vaccine. Third dose necessary. “
While neutralizing antibodies are an indicator of the body’s immune response, the scientists believe that other types of cells, such as B and T cells, will also be stimulated by the vaccines and help protect against the effects of the coronavirus. The preliminary data therefore cannot yet lead to the conclusion that the protective effect of the vaccines against severe Covid diseases is also reduced.
US expert Fauci expects higher transferability
In addition, initial analyzes from South Africa suggest that the Omikron variant tends to trigger less severe diseases than the previous variants. According to leading U.S. infectious disease expert Anthony Fauci, preliminary results suggest that the variant is likely to have a higher degree of communicability but is less severe.
The World Health Organization (WHO) classified Omikron as a “worrying variant” on November 26th. So far, however, there has been no evidence of a necessary adaptation of the existing Covid-19 vaccines to the Omikron variant, said their emergency director Mike Ryan.
With agency material
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