Sheba Medical Center has been studying 150 health care workers who received a second booster, or a fourth shot.
“Two weeks after administering the fourth vaccine, we see a good increase in the antibodies, higher than after the third dose, but not high enough against Omicron,” lead researcher Prof. Gili Regev-Yochay told reporters in an online briefing.
Israel, one of the most vaccinated countries in the world, has seen case rates skyrocket after the emergence of Omicron.
Early data indicated that the first booster restored some of the lost protection against infection, but that the protection again dropped after just a few weeks.
The same thing happened with the fourth shot.
“We see an increase in antibodies, higher than after the third dose. However, we see many infected with Omicron who received the fourth dose. Granted, a bit less than in the control group, but still a lot of infections,” Regev-Yochay told reporters.
While the vaccine protected well against the Alpha and Delta variants, “for Omicron it’s not good enough,” she added.
In other words, it doesn’t work.
Pfizer hasn’t responded yet.