How well did inactivated corona vaccines protect against the corona variant omicron? One of these vaccines does not perform well in a study.
Frankfurt – The Corona variant* Omikron is spreading rapidly all over the world. It has a particularly high number of mutations, especially on the spike protein. According to the Robert Koch Institute, among these amino acid changes are some that are known to affect transmissibility and immune escape. With the advent of the omicron variant, the concerns of many increased that the previously used corona vaccines * could possibly protect less well against corona infections and severe Covid 19 courses.
So far it is known: Due to the omicron variant, some vaccines, such as those from Biontech/Pfizer and Astrazeneca,* could no longer be as effective, which is why a booster vaccination is urgently recommended. According to an international study, Moderna’s vaccine is particularly suitable against the corona variant Omikron.* However, other players have now entered the vaccine market.
In addition to protein vaccines such as Novavax*, which work on the basis of viral protein particles produced in the laboratory, there are also so-called dead vaccines. One of them is Coronavac from the Chinese manufacturer Sinovac. But a study on this inactivated vaccine in particular is now delivering downright devastating results.
Dead vaccine Coronavac hardly works against Omikron: How does the Corona vaccine work?
Killed vaccines work on the basis of inactivated, i.e. killed, pathogens of the coronavirus. This is how the classic, well-known vaccines against tetanus or whooping cough work. As early as spring 2021, the WHO granted emergency approval for Coronavac, among other things. However, previous research has already shown that these dead corona vaccines have some disadvantages*.
In October 2021, a study in the journal Nature showed that the dead vaccines provided less protection against infection than the mRNA vaccines from Biontech/Pfizer and Moderna* or the vector vaccine Astrazeneca.* Other studies concluded that the amount of neutralizing antibodies is lower in inactivated vaccines.
The Omikron variant did not exist at that time, of course. This has changed now. Researchers from Hong Kong compared the effectiveness of the vaccine from Biontech/Pfizer* with the effect of Coronavac from the company Sinovac. For this purpose, it was examined how high the protection against the corona variant Omicron is when vaccinated people who received either Biontech or Coronavac as a first and second vaccination were then vaccinated with one of the two alternatives as a booster. The University of Hong Kong published the results.
Corona dead vaccine against omicron variant: study delivers sobering results
It turned out that people who had been vaccinated twice with the inactivated vaccine and who also received Coronavac as a booster did not develop a sufficient number of antibodies against Omicron. It was different for those who received the vaccine from Biontech/Pfizer as a booster. Regardless of whether they had received the inactivated vaccine as the first and second vaccination, their antibodies were at a sufficient level together with the mRNA booster.
In addition, the researchers came to the conclusion that neither a double vaccination with the inactivated vaccine Coronavac nor with Biontech/Pfizer caused sufficient formation of antibodies against omicron. “All those who have already taken two doses of Comirnaty [by Biontech/Pfizer ed. Red] or Coronavac should receive a third dose of the Comirnaty vaccine six months after their second dose. In this way, they can develop optimal protection against the omicron variant,” emphasized Malik Peiris, one of the leaders of the study. (slo) *fr.de is an offer from IPPEN.MEDIA.
Rubriklistenbild: © Secretary of Health Bogota/dpa
