HIV Positive Individuals More Likely to Respond to High-dose HBV Vaccine 

By Liz Highleyman

Due to overlapping transmission routes, many HIV positive people are also infected with hepatitis B virus (HBV). Further, HBV disease progression occurs more often in HIV-HBV coinfected individuals than those with HBV alone. For this reason, it is recommended that people with HIV should receive the HBV vaccine.

However, studies have shown that HIV positive people -- especially those with advanced immune suppression -- may not respond adequately to the standard HBV vaccine series.

As reported at the 4th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention last week in Sydney, Australia, researchers conducted a study to determine whether response rates would be higher in HIV positive individuals who received high-dose versus standard-dose HBV vaccination.

They retrospectively analyzed data from patients seen at a HIV clinic, comparing post-vaccination anti-HBs antibody titers in HIV positive individuals who received recombinant HBV vaccine at the standard dose of 10 mcg at months 0,1, and 6, versus those who received a higher dose of 40 mcg at months 0,1, and 6. All recipients were hepatitis B surface antigen (HBsAg) negative, hepatitis B surface antibody (HBsAb) negative, and hepatitis B core antibody (HBcAb) negative prior to vaccination. Patients were excluded from analysis if they did not complete all 3 injections in the series.

Results

• 42 individuals received the standard-dose vaccine (median age 41 years, 33% female, 43% with AIDS diagnosis, median CD4 cell count 398 cells/mm3, 88% on HAART).

• 11 subjects received the high-dose vaccine (median age 41 years, 55% female, 64% with AIDS diagnosis, median CD4 count 353 cells/mm3, 91% on HAART).

• 11 patients (26%) were responders to the standard-dose vaccine compared with 9 subjects (82%) who received the higher dose (P < 0.001).

• Among those with an AIDS diagnosis - indicating more advanced immune deficiency -- 3 subjects (17%) responded to the standard dose compared with all 7 (100%) who received the higher dose (P < 0.001).

• In a univariate analysis, no factors (including HAART use, sex, age, body mass index, or CD4 cell count) were predictive of a successful response to either vaccine regimen.

Conclusion

"HIV positive individuals were significantly more likely to achieve a successful response to primary HBV vaccination if they received high dose compared to standard dose, particularly in those individuals with an AIDS diagnosis," the researchers concluded. They added that further analysis with more subjects is being conducted.

08/03/07

Reference

A Bortan, S Shah, M Epstein, and others. The efficacy of high-dose hepatitis B vaccination in HIV-infected individuals. 4th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention. Sydney, Australia, July 22-25, 2007. Abstract MOPEB055.