The effect of late doses on the achievement of seroprotection and antibodytiter levels with hepatitis B immunization among adolescents

Objective. To determine the effect of varying dosing schedules and predicto r variables on the seroprotection rates and geometric mean titer levels res ulting from the hepatitis B vaccination series among adolescents. Methods. Adolescents received the hepatitis B vaccination series at varying schedules according to their natural adherence patterns. Data collected in cluded participants' medication use; chronic illness; use of cigarettes, al cohol, and marijuana; age; race/ethnicity; and body mass index. Participant s' dates of vaccinations were recorded and titer levels for hepatitis B sur face antibody were drawn similar to 12 and 24 months after study enrollment . The data for 498 participants were analyzed using chi (2) tests, Student t tests, logistic regression models, and analysis of variance. Results. Seroprotection rates among adolescents were not affected by late v accinations. The only factors affecting the achievement of seroprotection s imilar to 12 and 24 months after the first vaccination were body mass index and the number of immunizations received. Increased time between doses 1 a nd 2 and doses 2 and 3 showed a trend toward correlating with increasing ti ter levels. Conclusions. Although adolescents at risk of acquiring hepatitis B should r eceive the hepatitis B vaccination series in a timely fashion, late doses a re not detrimental, and may be beneficial, to achieving high antibody level s against the hepatitis B virus.