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Undervaccination for Hepatitis B Among Young Men Who Have Sex With Men -- San Francisco and Berkeley, California, 1992-1993

The evaluation of efforts to prevent hepatitis B virus (HBV) infection in the United States requires accurate measures of hepatitis B vaccination coverage among children and adults at risk for infection (1). Although vaccination coverage among children is obtained by nationwide surveys (2), vaccination coverage among adults at risk for HBV infection has not been well characterized. To estimate hepatitis B vaccination coverage among young men who have sex with men (MSM) (a group known to be at high risk for HBV infection and for whom hepatitis B vaccine has been recommended since 1982), CDC analyzed serologic data from the 1992-1993 Young Men's Survey (YMS) conducted by the San Francisco Department of Public Health (3). This report summarizes the results of that analysis, which indicate low hepatitis B vaccination coverage among young MSM in the San Francisco Bay area.

YMS used a targeted sampling method to enroll MSM aged 17-22 years at selected public venues (e.g., high-traffic street corners, dance clubs, bars, and parks) in San Francisco and Berkeley, California (3). During periods of recruitment, all young men who entered a predetermined area (e.g., stretch of sidewalk) at sampled venues were approached by YMS recruiters. Men who appeared to be substantially older than age 22 years were not approached. Young men who accepted approaches were interviewed by recruiters to determine their eligibility (i.e., aged 17-22 years and residence in the San Francisco Bay area) and willingness to participate in YMS. Participants provided blood specimens and were interviewed for sexual, drug-use, and health-care use practices in a specially-equipped mobile van. Blood specimens were tested for hepatitis B surface antigen (HBsAg), and antibody to both HBsAg (anti-HBs) and hepatitis B core antigen (anti-HBc). Because YMS was designed to measure the prevalence of human immunodeficiency virus (HIV) infection and related risk behaviors among young MSM, hepatitis B vaccination histories were not obtained from participants.

During July 1992-April 1993, YMS recruiters approached approximately 2000 young men during 96 sampling events at 26 different venues. Of 1773 (89%) young men who agreed to be approached, 778 (44%) were determined eligible, of whom 474 (61%) enrolled in the survey. Among these participants, 385 (81%) reported having had oral or anal sex with one or more men during the preceding 6 months. This analysis was restricted to these 385 men.

Among the 385 MSM, 77 (20%) had evidence of previous or current HBV infection, including 54 (14%) who were positive for both anti-HBs and anti-HBc, 18 (5%) who were positive for anti-HBc alone, and five (1%) who were positive for both HBsAg and anti-HBc. An additional 12 (3%) MSM were positive for anti-HBs alone, suggestive of hepatitis B vaccination. Among the 296 (77%) MSM who lacked evidence of vaccination or infection, 237 (80%) reported having had anal sex or having injected drugs during the preceding 6 months. Of these, 203 (86%) reported receiving care from one or more types of health-care providers, including private physicians; health maintenance organizations; hospitals; or school, community, or health department clinics.

Reported by: M Katz, MD, AIDS Office, San Francisco Dept of Public Health. Seroepidemiology Br, Div of HIV/AIDS Prevention, National Center for Prevention Svcs, CDC.

Editorial Note

Editorial Note: Despite the availability of an effective vaccine, the findings in this report suggest that only 3% of young MSM sampled at selected locations in San Francisco and Berkeley during 1992-1993 were adequately vaccinated against hepatitis B. The results also indicate that most (86%) young MSM who were still at risk for HBV infection were not vaccinated, despite receiving medical services from one or more health-care providers.

These findings are consistent with previous reports documenting that health-care providers in a variety of settings miss opportunities to vaccinate clients at risk for HBV infection (1,4,5). For example, at a Houston outpatient clinic for HIV-infected patients, clinic staff failed to prescribe hepatitis B vaccine to all patients for whom the vaccine was clearly indicated (4), and among MSM sampled at a Boston community health center, 84% reported having never been vaccinated against hepatitis B (5).

The findings in this report are subject to at least two limitations. First, these findings are limited to young MSM from the San Francisco Bay area who attended sampled venues. Hepatitis B vaccination coverage may vary among different groups of young MSM in the San Francisco Bay area and among young MSM in other regions of the country. Second, vaccination coverage may be underestimated when determined from serologic data alone. For example, some participants who were vaccinated against hepatitis B may not have developed a satisfactory response, or vaccine-induced anti-HBs may have waned below detectable levels. However, underestimation attributable to vaccine nonresponse or waning immunity is unlikely because of the young age and presumed healthy status (35 participants were HIV-infected) of participants.

Vaccination against hepatitis B is the most effective means of preventing HBV infection. Health-care providers should intensify their efforts to identify MSM and other candidates for vaccination during routine health-care visits (1). Susceptible persons at risk for HBV should be vaccinated, and routine vaccination should be provided to all infants and unvaccinated adolescents aged 11-12 years in accordance with published guidelines (1,6,7). As an integral part of prevention activities, health educators should promote the benefits of vaccination against hepatitis B and refer for evaluation MSM and other persons at risk for HBV infection.


  1. CDC. Hepatitis B virus: a comprehensive strategy for eliminating transmission in the United States through universal childhood vaccination

    • recommendations of the Immunization Practices Advisory Committee (ACIP). MMWR 1991;40(no. RR-13).

  2. CDC. State and national vaccination coverage levels among children aged 19-35 months -- United States, April-December 1994. MMWR 1995;44:613-23.

  3. Lemp GF, Hirozawa AM, Givertz D, et al. Seroprevalence of HIV and risk behaviors among young homosexual and bisexual men: the San Francisco/Berkeley young men's survey. JAMA 1994;272:449-54.

  4. Rabeneck L, Risser JMH, Murray NGB, et al. Failure of providers to vaccinate HIV-infected men against hepatitis B: a missed opportunity. Am J Gastroenterol 1993;88:2015-8.

  5. McCusker J, Hill EM, Mayer KH. Awareness and use of hepatitis B vaccine among homosexual male clients of a Boston community health center. Public Health Rep 1990;105:59-64.

  6. CDC. Update: recommendations to prevent hepatitis B virus transmission -- United States. MMWR 1995;44:574-5.

  7. CDC. Adolescent immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American Medical Association (AMA). MMWR 1996 (in press).

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