Study Status: Completed
Recruit Status: Completed
Study Type: Observational
Official Title: Impact of Vaccination on Th2 Immunity in Infancy
Brief Summary: The purpose of this study is to assess the responses in the immune system of infants after they receive the vaccine against diphtheria, tetanus, and pertussis (DTaP). The investigators will do this by studying the immune cells and allergy responses in the blood prior to and after receipt of the third DTaP vaccine.