Immune system defenses While studies show that boosters temporarily increase antibody levels, scientists say the goal of a vaccine regimen is to elicit not only antibodies but second-line immune system defenses such as T-cells. "All that is going to be helpful for keeping you out of the hospital," said Dr.
Peter Hotez, a vaccine expert at Baylor College of Medicine. Multi-dose vaccines prime the immune system, giving it time to marshal those back-up defenses.
Dr. Luciano Borio, a former Food and Drug Administration acting chief scientist, said, "I do worry that we don't know what impact it may have on the immune system maturation of the doses.