Omicron variant, study: fourth dose vaccine ineffective

The fourth dose of Pfizer or Moderna vaccine against covid does not provide much additional protection against contagion of the Omicron variant. This is what emerges from a study conducted in Israel, where the fourth dose is administered to medical personnel, as well as to frail people and over 60 years. “The growth in antibody levels that we see with Moderna and Pfizer is slightly higher than what we have seen after the third dose of the vaccine,” says Gili Regev-Yochay, director of the infectious disease unit at Sheba Medical Center in Tel Aviv, who conducted the research. “Despite the increase in the level of antibodies, the fourth dose offers only a partial defense against the virus” – explains the professor – “we have seen many people infected with Omicron after the fourth dose. A little less than in the control group, but always many “. According to Regev-Yochay, “the vaccine is excellent against alpha and delta variants, but not good enough for omicron.” The professor stressed that the study is still at the preliminary stage and for this reason not all the data have been released. The research was conducted on 150 people who received a fourth dose of Pfizer two weeks ago. Another 120, who had taken three Pfizer doses, received a fourth dose of Moderna a week ago. This is the first research on the fourth dose also conducted with the combination of different vaccines, but the results of the two groups after a week appear very similar. The results open a reflection on the fourth dose strategy adopted in Israel. According to Regev-Yochay, it is probably a good idea to give the fourth dose to high-risk groups. However, the current strategy could be corrected by only targeting older people.