Hepatitis B vaccination rate of homeless children in Baltimore

Objective: To investigate the hepatitis B vaccination rate in homeless children 2 to 18 years old living in Baltimore City. Methods: During a 21-month period, 250 children from homeless shelters were enrolled. Results: The percent of children who had received 3 or more doses of hepatitis B vaccine was inversely related to age; 90% in 2- to 5-year-olds and 29% in 13- to 18-year-olds (P < 0.0001). Seventy percent of 2- to 5-year-olds had at least some of their vaccine history recorded in the Baltimore Immunization Registry Program but the history was complete in only half. Forty-two percent of 13- to 18-year-olds had no hepatitis B vaccine doses recorded in any source; 49 per cent of 10- to 18-year-olds were either not immunized or had received only one hepatitis B vaccine dose. Conclusions: Hepatitis B vaccine coverage is high in homeless children up to 9 years of age, whereas the majority of homeless children 10 years of age and older are unprotected against hepatitis B virus infection. Tracking the vaccine records in homeless children is labor intensive. Better public health strategies to deliver hepatitis B vaccine to older homeless children are urgently needed.