A study in Israel found that the fourth dose of the Covid-19 vaccine had almost no effect on protection against the Omicron variant, according to the DPA.
After the fourth dose, the antibodies in the health care workers who participated in the study returned to the level as after the third injection. Infections were again common.
The healthcare workers who fell ill mostly had mild symptoms, but most had a high viral load and were potentially infectious.
The data show that the fourth dose does not increase immunity, but only returns it to higher levels.
The authors conclude that “the low efficacy in preventing infection with mild or asymptomatic Omicron and the potential for infection transmission by those infected point to the urgent need to develop next-generation vaccines.”
“These data from Israel are rather against a fourth dose for everyone,” German Health Minister Karl Lauterbach tweeted.
“However, for older and vulnerable people, the fourth dose will be more beneficial because of the supposed effect against severe symptoms and death,” the authors said.