Since the discovery of Omikron in South Africa, experts fear that the variant could escape the protective effect of the vaccination. The first laboratory data are now available. However, this does not mean that all questions have been answered.
What about my vaccination protection against Omikron? Millions of vaccinated people are asking themselves this question. The first laboratory studies on the effect of corona vaccines against omicron indicate a comparatively weak defense reaction against the new variant. The virologist Sandra Ciesek from the University Hospital Frankfurt published the first results on Twitter, which show a significantly reduced antibody response of various vaccines to the new variant.
The companies BioNTech/Pfizer also announced that, according to preliminary results, two doses of their Comirnaty vaccine do not provide sufficient protection against infection with the recently discovered variant. A booster dose is needed to increase the antibody level. The day before, South African experts had presented similar data on a weaker antibody response. None of the data presented has been reviewed by peers and has not been published in a specialist journal.
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Adaptation of the corona vaccines against omicron probably necessary
«The data confirm that the development of a vaccine adapted to Omicron makes sense,» Ciesek wrote on Twitter about the results she presented. However, she also pointed out that the data did not allow any statement to be made as to the extent to which vaccinated people are protected from a severe course when infected with the omicron variant. Because the immune response is not only based on antibodies, but also on T cells, for example.
The vaccine developers Pfizer and Biontech assume that just two doses of their vaccine will protect against serious illnesses. The T-cells that are formed after the vaccination are not affected by the mutations in the omicron variant.
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How is the effect of a vaccine against virus variants tested?
In order to examine the effect of a vaccine against a specific variant of Sars-CoV-2, researchers usually carry out so-called neutralization tests. You look at how many antibodies a vaccinated person has in their blood that can bind to the virus variant and thus switch it off. However, the actual protection of vaccinated persons cannot be determined with this. This requires clinical studies with thousands of subjects or evaluations of the ongoing infection process.
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Antibody response reduced at omicron
According to Ciesek, the antibody response against omicron is drastically reduced compared to the delta variant – it is up to 37 times lower. There is also a reduction in people with a booster vaccination. Immunologist Carsten Watzl emphasized that those who had been vaccinated were not completely defenseless. «The results clearly show that the neutralizing antibodies of vaccinated people are also able to bind and neutralize omicrons. The vaccinations are therefore not useless,” the Secretary General of the German Society for Immunology comments on the results. «But: You need significantly higher antibody levels to successfully neutralize omicron – about 40 times more.»
Christian Drosten pointed out that the results of studies presented so far came to similar conclusions and came to the conclusion: «It doesn’t look good for those who have been vaccinated twice. Third dose needed,» tweeted the virologist from the Berlin Charité. Drosten assumes that Omikron will cause problems in Germany from January. The variant will probably make it necessary to adapt the existing vaccines, he said on Tuesday evening in the “Coronavirus Update” podcast on NDR-Info. Apparently, this is the only way to ensure adequate vaccination protection against omicron.
Vaccine manufacturers respond to omicron variant
The companies BioNTech and Pfizer have already started to develop a version of their vaccine adapted to the omicron variant in order to o increase vaccination protection. This work would continue, first batches could be produced and delivered within 100 days if approved by the authorities. If necessary, an adapted vaccine can be made available from March. The expected production volumes of four billion doses of the vaccine in 2022 would not change even with a necessary adjustment.
According to their investigations, after two doses of the vaccine, the neutralization potential was reduced by a factor of 25 compared to the wild type of the pathogen. The booster dose reportedly increased the antibody level by a factor of 25. These antibody levels would be associated with high potency against both wild-type virus and previously emerging variants. Data on the longevity of the antibody titers induced by the booster are still being collected.