A government-commissioned study presented to senior health officials earlier this week strengthens the case for giving them a fourth jab for immunocompromised people.
The survey, conducted by the Head of Infectious Diseases at Sheba Medical Center Prof. Galia Rahav, examined the effectiveness of the booster in immunocompromised people three months after receiving it.
The study reportedly examined the rate of antibodies among 78 kidney transplant recipients, about 120 bone marrow transplant recipients and about 100 heart transplant recipients.
The data was presented to the Health Ministry's expert panel on pandemics during a meeting regarding the vaccination of children aged 5-11 who recovered from the virus and a possible fourth shot for the immunocompromised.
The decision regarding administering the fourth vaccine, which will be based on the research, is set to be made after data has been collected six months following receiving the third shot.
While the study showed that all three groups responded well to the booster, the rate of antibodies among heart transparent recipients was the lowest among the surveyed.
"For heart transplant recipients I would recommend getting vaccinated again after half a year because their antibody level is now considered to be particularly low," Rahav wrote in the study.
Earlier Wednesday, BioNTech and Pfizer said a three-shot course of their COVID-19 vaccine were able to neutralize the new Omicron variant in a laboratory test and they could deliver an Omicron-based vaccine in March 2022 if needed.
In the first official statement from vaccine manufacturers on the likely efficacy of their shot against Omicron, BioNTech and Pfizer said that two vaccine doses resulted in significantly lower neutralizing antibodies but that the third dose of their vaccine increased the neutralizing antibodies by a factor of 25.
Blood obtained from people that had their third booster shot a month ago neutralized the Omicron variant about as effectively as blood after two doses fought off the original virus first identified in China.