Kids aging 4-6 years, such as Gavin, should receive 4 vaccines: DPT vaccine, which belongs in a class of combination vaccines against three diseases (diphtheria, pertussis (whooping cough), and tetanus); MMR vaccine, which is an immunization vaccine against measles, mumps, and rubella (German measles); IPV vaccine, which is a vaccine against Polio; Varicella vaccine, which is a vaccine against chicken pox.