Normal immune response to hepatitis B vaccine in patients with Down's syndrome. A basis for immunization guidelines.

Institutionalized patients with Down's syndrome (DS) are uniquely predisposed to develop chronic hepatitis B infection following exposure. Therefore vaccination is particularly warranted, but there have been concerns that these individuals may react suboptimally. We examined the immune responses of 62 institutionalized patients with DS to 20 and 40 micrograms of hepatitis B vaccine inactivated (Heptavax-B) over one year. The subjects were matched by weight, age, and sex. Seroconversion rates and levels of antibodies to hepatitis B surface antigen (anti-HBs) were comparable to those found in a normal population and were higher than those found in immunocompromised patients undergoing hemodialysis. The anti-HBs levels were consistently higher in the 40-micrograms vaccine group. In patients with DS who were over 30 years old, age was a significant factor in predicting anti-HBs responses. Conversely, in younger subjects, weight was negatively correlated with anti-HBs levels. These data clearly indicate that patients with DS respond normally to hepatitis B surface antigen vaccination and need not be considered a special group when guidelines for vaccination are recommended.