Lack of seroconversion after hepatitis B virus immunization.

Abstract

In their article “Hepatitis B Virus Immunization Among Young Injection Drug Users in San Francisco, Calif: The UFO Study,”1 Lum et al. describe a lack of hepatitis B virus (HBV) surface antibody seroconversion at 4 weeks after completion of the 3-dose HBV vaccination series in injection drug users (IDUs). Only 78% of the subjects underwent anti-HBV surface antibody seroconversion. All UFO subjects were IDUs aged younger than 30 years. Among subjects who completed the vaccine series, 80% were White; 71% were male and 34% were gay or bisexual. While 41% were hepatitis C virus (HCV)–seropositive, only 1% were HIVinfected. Lum et al. propose that injection drug use likely blunts the immune response to HBV vaccination, but they also suggest that HCV infection may be partially responsible for the inadequate serological response. The lack of seroconversion in the UFO Study was similar to results previously reported in the Seattle Young Men’s Survey (YMS), where 69% of men who have sex with men who reported a full HBV vaccination series had HBV surface antibodies.2 YMS subjects who reported receiving the 3-injection HBV immunization series were similar to UFO subjects in that they were aged younger than 30 years and were predominantly White men (68%). However, only 9% reported any injection drug use; 1% were HCV-seropositive. Four percent were HIVinfected. Since the YMS relied on selfreport of vaccination status and the time since HBV vaccination was longer than in the UFO Study, inaccurate recall regarding vaccination and waning antibodies may have played a role in the lack of HBV seropositivity among YMS participants who reported completing the HBV immunization series. The results of the UFO and YMS studies demonstrate that HBV seroconversion, whether after documented completion of a vaccination series or self-reported receipt of 3 vaccines, does not equal the close to 100% serological response in young adults reported by vaccine manufacturers.3,4 Thus, screening for presence of HBV antibodies before vaccination may be useful in patients who report prior HBV vaccination and injection drug use or having sex with other men as HBV risk factors.