More than 240 million people worldwide are chronically infected with hepatitis B virus and about 600,000 people die each year as a consequence. A highly effective three-dose series of hepatitis B vaccine has been available since 1982, and is safe for HIV-infected children and adolescents. However, immune suppression resulting from HIV infection can reduce the protective antibody response to hepatitis B vaccination.
Recently, Thai investigators evaluated the prevalence of hepatitis B infection in 521 perinatally HIV-infected adolescents between 12 and 25 years of age as part of a TREAT Asia-supported study.1 The study was conducted at four TREAT Asia pediatric network sites in Thailand.
The average CD4 cell count among the adolescents taking part in the study was 685 cells/mm3. Among the 81 percent of adolescents taking part in the study who had viral load testing, 86 percent had HIV viral loads less than 400 copies/mL. Although 54 percent had a reported history of hepatitis B vaccination during childhood, only 14 percent were revaccinated after immune recovery following antiretroviral therapy (i.e., after their CD4 cell counts returned to normal levels). The investigators then found that only 18 percent tested positive for protective antibodies against hepatitis B—whether from being vaccinated or as a result of a previous infection. Those with protective antibodies were older, had a higher CD4 cell count, and were more likely to have had a history of hepatitis B vaccination. Although the overall prevalence of HIV–hepatitis B co-infection was low at 3.3 percent, 69 percent of co-infected children had elevated levels of hepatitis B in their blood, and 75 percent were already resistant to one of the medicines that can be used to treat both infections (i.e., lamivudine, or 3TC).
HIV-infected adolescents who have never been vaccinated or have no evidence of antibody protection on blood testing should undergo immunization with a full three-dose series. Although this approach is standard in the U.S. and some other high-income countries, it is not in most Asian countries. Vaccination programs that are usually focused on infants need to create mechanisms for older children and adolescents with HIV to be tested for hepatitis B and vaccinated or revaccinated following immune recovery. Failure to do so is leaving thousands of HIV-positive Asian adolescents at risk of becoming co-infected with hepatitis B and developing serious liver disease.
1.
Aurpibul L, Lumbiganon P,
Kolasaraksa P, Hansudewechakul R, Sa-Nguanmoo P, Taeprasert P, Bunupuradah T,
Pooworawan Y, Sirisanthana V, Puthanakit T. HIV and Hepatitis B Co-infection
among Perinatally HIV-infected Thai Adolescents. Pediatric Infectious
Diseases Journal. 2012 May 15.