In specific aim 3, asthmatic children were tested in two stages. In stage one, a preliminary study was performed in children with relatively mild asthma who were immunized with hepatitis vaccine. Samples were collected at various time points and assayed for antigen-specific antibody. The hypothesis that asthmatic children would have a Th2 type response rather than the Th1 type response in normal children was evaluated by determining times at which samples could be collected from the larger Childhood Asthma Management Program (CAMP) study.