A two-dose Covid 19 vaccine does not produce sufficient neutralizing antibodies against the Omicron variant, according to a British study. Oxford University scientists came to that conclusion after laboratory tests on blood samples from vaccinated people who received the vaccine from AstraZeneca or BioNTech/Pfizer. However, they said there is no evidence yet that the lower antibody levels with Omicron lead to a higher risk of serious illness or death.
Neutralizing antibodies not enough
“These are important data, but they only show part of the picture. They only look at neutralizing antibodies after the second dose, but tell us nothing about cellular immunity, and that is also being tested,” said vaccine scientist Matthew Snape, one of the authors of the study presented Monday, which has not yet been reviewed by independent experts.
British Prime Minister Boris Johnson had warned over the weekend that two vaccinations would not be enough to keep Omicron at bay. He therefore wants to make speed on booster vaccinations.
Biontech and Pfizer had published study results last week showing that their vaccine was effective against the Omicron variant after three doses – but had significantly lower neutralization titers against Omicron after two doses, making it less effective. Biontech CEO Ugur Sahin therefore considers earlier booster vaccinations advisable, possibly as early as after three months.
Partial protection against severe courses
Even if severe courses of Covid-19 disease are becoming rarer overall, this does not say anything about the Omicron virus variant. That’s because many people infected with the new variant had recovered or been vaccinated before infection, he said. “This is probably the main reason for the few severe courses, not the properties of the virus itself,” said Basel biophysicist Richard Neher.
According to the researcher at the University of Basel’s Biozentrum, Omicron’s transmission rate is nearly three times that of the Delta variant. “However, this is not due to the virus itself, but to the fact that vaccinated and unvaccinated people are infected,” Neher, a member of the scientific task force, said in an interview published on the University of Basel website. If developments continue as they have, Omicron will be prevalent in Europe in about two to four weeks, he said.
At the very least, the Corona vaccine continues to protect against severe courses, more and more evidence suggests. Although full vaccine protection may no longer be available, the booster could partially compensate for this.
Omicron may have benefited from medical disparity
Researchers are collecting Sars-CoV-2 genomes on the online platform “Nextstrain” to track the evolution and spread of the virus and its different variants. Of the six million fully sequenced viral genomes now available worldwide, there are already 1200 genome sequences for Omicron alone, Neher said. But the question of the variant’s origin remains unresolved, he said, because no closely related variants are known.
Several possibilities for the origin of the Omicron variant are being discussed among experts. One of these is that Omikron arose in a severely immunosuppressed patient – for example, in an inadequately treated HIV-infected person. This is because chronic infections can develop in their bodies, where the virus can persist and mutate over a long period of time.
So Neher said, “I think it’s important to realize that we need to reduce inequality in the global health system.” He said this is true with regard to Covid-19, vaccines and infectious diseases in general.
- source: diepresse.at/picture:pixabay.com
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