Prevalence and Correlates of Previous HBV Vaccination Among Young Drug-user
Abstract and Introduction
Hepatitis B (HBV) vaccination coverage remains low among drug users. In 1997, ACIP made hepatitis B vaccine available for persons aged 0â€“18 years and many states began requiring HBV vaccination for entry into middle school; these programs might affect HBV vaccination and infection rates in younger DUs. We were interested in determining correlates of immunization among younger (<25 years) and older (25 and older) DUs. Methods: A community-based sample of 1,211 heroin, crack, and cocaine users 18 or older was recruited from Harlem and the Bronx. We assessed previous HBV vaccination and infection and correlates using bivariate analyses. Results: The sample was predominantly male (74.0%), aged â‰¥25 years (67.1%) and Hispanic (59.9%). In terms of socioeconomic status, 57.1% had less than a high school education, 84.5% had been homeless in their lifetime, and 48.0% had an illegal main income source. Among 399 DUs younger than 25 years of age, 30% demonstrated serological evidence of previous vaccination, 49.9% were susceptible to HBV at baseline, and 20% showed evidence of infection. In our model, previous HBV infection and vaccination status were associated with being 22 years old or younger (AOR = 1.40 and 1.66). Compared to susceptible individuals, those vaccinated were significantly less likely to be born in other countries (AOR = 0.50). Among 812 DUs 25 and older, 10.6% demonstrated serological evidence of previous vaccination, 59.2% were susceptible to HBV at baseline, and 30.2% showed evidence of infection. Conclusion: Existing interventions to increase HBV vaccination among adolescents should target high risk groups.
Hepatitis B virus (HBV) infection continues to be a major public health concern in the 21st century, with an estimated 1.25 million Americans being chronic carriers and an estimated 5,000 deaths from chronic liver disease each year. Parenteral transmission of HBV through injection drug use practices accounts for more than half of all HBV cases. Additionally, the prevalence of HBV infection among injection drug users (IDUs) ranges between 40% and 81%.
An effective recombinant HBV vaccine has been available for more than 20 years. Introduced into the childhood immunization schedule in the US in 1991, the HBV vaccine has been recommended for a variety of individuals including those at occupational risk of infection (e.g. health care workers), men who have sex with men (MSM), sexually transmitted disease (STD) patients, and IDUs. Despite these strategies to reduce HBV, the estimated number of new hepatitis B infections was still 60,000 in 2004; adults accounted for 95% of the cases; the majority registered among the 25â€“44 year old group, followed by the 15â€“24 year old and the older than 45 groups; in general, vaccination rates remain low in adult high risk groups.
HBV vaccination is required for entry into middle school in 37 of the 50 states and the District of Columbia since 1997 or later. In addition, in 1995, the Advisory Committee on Immunization Practices (ACIP) recommended vaccination of all unvaccinated children 11 years of age and younger, and in 1997, this recommendation was expanded to all unvaccinated adolescents aged 18 and younger. These mandates and recommendations should result in higher vaccination rates in younger adults. However, some adolescents and young adults in high risk groups, who should have been part of the group covered by these recommendations and HBV vaccination programs have been, and continue to be, missed by these vaccination programs and catch-up schemes and thus remain susceptible to HBV. This has been implied in studies of HBV and younger IDUs and even lower vaccination rates have been reported in studies of younger MSM aged 15â€“22 years, where vaccination coverage is 9% despite 90% reporting regular access to health care. Clearly, many adolescents are slipping through the cracks and not receiving HBV vaccination.
In this study we aimed to compare the serologic prevalence and correlates of previous HBV infection and vaccination among younger (less than 25 years old) and older (25 and older) IDUs and NIDUs among new recruits to a prospective study of young injection and non-injection heroin, crack, and cocaine users in Harlem and the South Bronx in New York City.