Administering a third coronavirus vaccine shot to immunocompromised patients significantly increases their ability to produce antibodies, preliminary results from research conducted by the Rabin Medical Center-Beilinson Campus in Petah Tikva and Clalit Health Services has shown.
On July 12, Israel began to offer a booster shot for people with a severely weakened immune system. Among the eligible patients were recipients of organ transplants. Research had shown that a significant percentage of them had not developed antibodies after the first two shots.
Beilinson and Clalit researchers analyzed how the immune systems of people who had received organ transplants responded. Those who had received heart, lung or kidney transplants developed antibodies at almost double the rate after the booster shot, while the amount of antibodies for those who had received a liver transplant increased by about one-third, they found.
Seventy-three percent of patients who had received the third vaccine developed antibodies, compared with 35% after the first two shots, according to Dr. Ruthi Rachmimov, director of Beilinson’s Kidney Transplant Unit.
Among lung-transplant recipients, 33% developed antibodies after the booster shot, compared with 18% after the first two shots.
For heart-transplant recipients, the rates were 58% after the third shot and 31% after the second shot. For liver-transplant recipients, 71% developed antibodies after the third shot, compared with 47% after the second shot.
Antibody development represents only part of the immune system’s defenses against a disease, and the body may build up other forms of protection though so-called cellular memory. But recent research has indicated there is a connection between the antibody count and the risk of getting infected.
“The data is clear proof that the third vaccine works,” Rachmimov said. “We see a significant improvement in response to the third vaccine in kidney-transplant recipients. I recommend that everyone who is an organ-transplant recipient go and get vaccinated.”
Prof. Mordechai Kramer, director of Beilinson’s Lung Disease Division, and Dr. Marius Brown, director of the National Institute of Liver Diseases, said no significant side effects have been recorded.
“No significant side effects were seen in those who got vaccinated other than local pain at the injection site in the few patients,” Kramer said. “There were no rejection events from the vaccine.”