Hepatitis A and B, DTP (Diphtheria, Tetanus, Pertussis.) Polio, MMR (Measles, Mumps, Rubella), Chicken pox, Influenza, Tetanus, BCG, Rotavirus, etc.
Vaccines consist of dead or weakend microbes. When these are swallowed or injected, the body produces antibodies to fight them.
These antibodies remain in the body and protect it from any future attack of the disease causing microbes.
Therefore, vaccines are given to infants for preventing diseases.