Some Israelis with weakened immune systems are likely to be offered fourth vaccine shots within weeks, a member of the government’s pandemic advisory panel has said.
Prof. Galia Rahav, head of Sheba Medical Center’s Infectious Disease Unit, told The Times of Israel on Tuesday that while fourth shots for the general population have been ruled out for now, her ongoing research underscores their importance for some.
“In about two weeks I’ll give my recommendations and we’ll probably advise giving fourth vaccinations for some immunocompromised people,” said Rahav, who is conducting some of the key research that led to Israel’s rollout of boosters.
The research examines antibody levels among more than 300 people who are considered immunocompromised for different reasons.
Independently, Sheba said that it is conducting a study of the feasibility of a 4th shot in a trial among some 200 volunteers, examining the effect of antibody levels.
The hospital said it was the first such trial in the world and would be carried out in cooperation with the Health Ministry.
Unlike the third shots, which were rolled out across the board to all immunocompromised Israelis as soon as they were deployed, fourth shots are likely to be given sparingly. Rahav said the approach should be very differential, focusing on people with specific conditions that make them particularly vulnerable.
“In our research we are finding very different situations among the immunocompromised,” she said. “People with HIV are responding to the vaccine and people with multiple myeloma likewise, even though they normally have problems with antibodies and don’t generally respond well to vaccines.
“There are also differences among people who have received transplants. Patients who had bone marrow transplants are still responding well to the third shot, but patients who got heart and kidney transplants aren’t. The same is true of leukemia patients.”
She commented: “Immunosuppression is very different for different patients, therefore the response to the vaccine is very varied. Some immunocompromised people respond to the vaccine like healthy people and others don’t.”
Rahav said that the “exciting news” from her ongoing study is that, in general, the vaccine is “very immunogenic,” meaning it provokes a good immune response even among those who often struggle to muster one.
However, she acknowledged that there are some people who aren’t responding to the vaccine, and said that for such people, if they have taken three shots and still aren’t developing immunity, a fourth shot is unlikely to help, and there is not much point in administering one.