Covid-19 vaccines offer virtually no protection against omicron
Individuals who are double-vaccinated with Covid-19 vaccines or recovered from COVID-19 have “virtually no protection” against the Omicron variant, according to a peer-reviewed study.
The research, led by Rudolf Valenta of the Medical University of Vienna, found that only people who had received the third dose of a COVID-19 vaccine can form antibodies that could partially block Omicron, although noting that the protection is far from optimal.
“The third vaccination developed protective antibodies in many individuals,” Valenta said, adding that “there is also a significant proportion (20 percent) in whom no protection was established.”
According to results of the study recently published in the journal Allergy, researchers with the Medical University of Vienna examined an Austrian subpopulation of people who had been vaccinated or recovered from the CCP (Chinese Communist Party) virus. Scientists examined individuals’ antibody status and protection against the Wuhan, Delta, and Omicron variants, strains that are currently prevalent in the European country.
The study involved people who received all types of COVID-19 vaccines and vaccine combinations currently licensed in Austria.
Regarding the Omicron variant, researchers developed a test for the previous variants that investigates whether the COVID-19 strain can bind to the receptor on human cells via its receptor-binding domain (RBD).
“The results showed that both COVID-19 convalescent individuals and individuals who had been vaccinated twice had developed antibody protection against Delta. However, the antibodies were not able to block receptor binding against Omicron,” the researchers found.
An RBD is a key part used by a virus, including the CCP virus, to enter the “spike protein” domain that allows viruses to dock to the human body, gain entry into cells, and lead to infection.
The RBD differed only slightly in all CCP virus variants previously known, researchers said, adding that the COVID-19 vaccines that are currently available could provide protection against infections caused by these previous strains.
The researchers noted that the best protection would be to develop a broadly effective combination vaccine that could protect against both the previous CCP virus variants and Omicron.
“Until we have such a vaccine, only repeated vaccinations with the existing vaccines will provide some protection,” Valenta said. “The protective effect achieved by vaccination can be evaluated with special tests that can be rapidly adapted to new virus variants.”