Omicron spreads furiously because the new variant is even more contagious than Delta. Only booster vaccination offers some protection against infection. Researchers from Austria have now discovered that a "super immunity" is also possible from two factors can neutralize the viruses.
Omikron is spreading rapidly around the world. Case numbers also rising rapidly in Europe. In countries such as the United Kingdom and Denmark, the new variant already accounts for a large part of the sharp rise in infections.
Omicron also on the rise in Germany. According to figures from the Robert Koch Institute (RKI), 10 nationwide are now being.443 cases of this new and very contagious variant have been assigned (as of 28.12). But the number of unreported cases is likely to be much higher, as much less testing is done over the holidays. In addition, many health departments and agencies are closed and not reporting numbers.
Study: Titers of vaccinated and recovered people were compared
Since previous studies have already shown that a two-factor vaccination does not protect against infection with Omikron and only a booster has some protective effect in this regard, the uncertainty among many is great. However, a new small study with fewer than 100 participants from Austria, now published in the preprint and not yet peer-reviewed by independent experts, now shows that even against omicron, a so-called "super-immunity" is possible is possible.
Medical experts refer to this as immunity that can neutralize all forms of Sars-CoV-2. Another word for this is hybrid immunity. It occurs in people who have received a vaccination but then still have undergone a Sars-CoV-2 infection or vice versa and is therefore probably the best protection against the new Omikron variant.
Researchers at the American Rockefeller University in New York had such a "super-immunity" already discovered in a study published in September in the journal Nature. To do this, they modified the spike protein of the coronavirus in the laboratory, which is responsible for entry into the cells in the human body. A spike mutant with 20 alterations was created, which was completely resistant to the neutralizing antibodies of most of the vaccinated and recovered people – similar to what is now the case with Omikron. Only those vaccinated who had already been infected with Corona and had Covid-19 before their vaccination were able to fight the mutant virus much better than those who had "only" been vaccinated or recovered. "It is very likely that they will be effective against any future variant that Sars-CoV-2 throws at them," said then virologist and study author Theodora Hatziioannou.
- Read more:First infected, then vaccinated: researchers find super immunity against Corona
Cross-vaccination offers better protection against omicron than vaccine alone
The Austrian researchers around Annika Rossler of the Institute for Virology of the University of Innsbruck tested the antibody titers for their study of both recovered persons and persons vaccinated with Astrazeneca, Biontech/Pfizer and with Moderna against the new Omikron variant and compared them with other variants such as Delta. In doing so, the researchers confirmed what had been shown in several studies before: the vaccine antibodies can neutralize Omicron to a much lesser extent than other variants.
A certain neutralization of the virus by the antibodies compared to other variants could only be found in persons who were fully vaccinated with Biontech and in persons who were cross-vaccinated – i.e. first with Astrazeneca and then with Biontech.
This showed slightly better protection against omicron than the other vaccines. In contrast, people who had only been vaccinated with Astrazeneca were no longer protected from infection.
"Superimmune" can neutralize Omikron much better
Among the so-called "superimmunes, who had either already undergone a Sars-Cov-2 infection and then been vaccinated once or twice with Biontech, or vice versa, it was different: their antibodies were able to neutralize Omikron. However, this does not mean that people should deliberately infect themselves with Sars-CoV-2 in order to achieve "super immunity" to produce.
Instead, the study authors point out that despite the "super-immunity" everything speaks in favor of rapid development of variant-adapted vaccines. Even if a booster similar to an additional infection can increase the antibody level and probably still protect against severe disease progression.
Booster protection against omicron also wears off over time
Some studies have already shown that a third vaccination offers better protection against Omikron than a double vaccination does. According to laboratory results from Sandra Ciesek, a virologist in Frankfurt, the booster offers 58 to 78 percent protection against Omikron about two weeks after vaccination. After three months, however, this fell again significantly. That’s why the virologist also cautioned against relying solely on third party vaccination and neglecting protective measures. There have been cases of boostered individuals who have become infected and infected others with Omicron.
Even if a high enough level of protection against infection cannot be produced by the approved vaccines, however, researchers believe that the vaccines will still protect against severe progression through an Omikron infection. Because it is not only antibodies that are crucial for the immune response in the body, but also T cells.
Vaccines protect against severe course before Omikron
A very new study from South Africa presents promising data in this regard. There, mainly Biontech and Johnson& Johnson vaccines. The South African Medical Research Council (SAMRC) and Discovery, the largest private health insurer, analyzed suspected Omikron cases for this purpose. SAMRC President Glenda Gray said of Johnson& Johnson: "The good news is that the vaccine is shown to be effective in preventing severe disease and death."From Biontech, there is also evidence that the vaccinated can still outsmart the mutant – because it does not escape the T-cell response. In contrast to the antibodies.
Omikron could produce milder courses
Initial data from South Africa also provided evidence that Omikron could produce milder courses than previous variants in the pandemic. Meanwhile, further studies seem to confirm these initial data. For example, a new study from South Africa that analyzed data from infected people from early October to late November shows that Omikron carries up to an 80 percent lower risk than Delta of infected people needing to go to the hospital for treatment. Once the patients were in the clinic, however, there was no difference in the subsequent course of treatment.
"The very encouraging data strongly suggest a lower severity of the Omikron infection wave", Cheryl Cohen of South Africa’s National Institute for Communicable Diseases (NICD) said. She cautioned, however, that this is still early data and more studies are needed.
A U.K. laboratory study of so-called pseudoviruses also showed that Omikron is worse at infecting lung cells compared with Delta and therefore could trigger milder courses of disease. However, the authors emphasize that it is unclear to what extent the results can be transferred to real life.