Health Minister Nitzan Horowitz, 56, rolled up the sleeve of his black polo shirt before a nurse plunged a syringe into his arm in Kfar Saba's Meir Medical Center north of Tel Aviv.
They work by exposing the body to killed or weakened versions of a germ or part of it , which trains the immune system to fight the foreign invader if a child later encounters it.
Only minute quantities remain in vaccines see table below.
The researchers used those to measure the children's antibody responses to four routine childhood vaccinations.
S vaccine at a dose of 5×1010 viral particles low dose or 1×1011 viral particles high dose per milliliter or placebo in a single-dose or two-dose schedule.
Critically, vaccines spur the immune system to generate antibodies that recognize particular proteins on the germ's surface.