Reuters Health Information (2011-04-12): More immunogenic HBV vaccine regimens better in HIV-infected patients
Drug & Device Development
More immunogenic HBV vaccine regimens better in HIV-infected patients
Last Updated: 2011-04-12 16:00:06 -0400 (Reuters Health)
NEW YORK (Reuters Health) - The standard hepatitis B vaccine regimen may not be ideal in HIV-infected patients, according to results of a randomized controlled trial.
In the April 13 issue of JAMA, researchers report that a 4 intramuscular double-dose regimen and a 4 intradermal low-dose regimen "improved serological response compared with the standard HBV vaccine regimen."
"In my opinion, our results will change the practice of hep B vaccination in adults with HIV infection," first author Dr. Odile Launay, from Hopital Cochin, Paris, France, wrote in an e-mail to Reuters Health.
HIV-infected patients are at increased risk for liver-related morbidity and mortality, the study team notes in their report. Therefore, current guidelines recommend that all patients with HIV infection who are negative for HBV markers should be immunized for HBV.
However, immunogenicity of HBV vaccination is lower in adults with HIV infection than in healthy adults. Alternative HBV vaccine schedules that are more immunogenic than the standard HBV vaccine schedule are needed in HIV-infected patients.
The standard HBV vaccine regimen involves 3 intramuscular injections of 20 �g of recombinant vaccine at weeks 0, 4, and 24 (IM20X3).
Against the standard regimen (IM20X3), Dr. Launay and colleagues tested two alternatives: 4 intramuscular double doses (40 �g -- 2 injections of 20 �g of vaccine at weeks 0, 4, 8 and 24 -- IM40X4 group) and 4 intradermal injections of low doses (4 �g -- 1/5 of 20 �g at weeks 0, 4, 8, and 24 -- ID4X4 group).
A total of 437 patients who were HBV seronegative and had CD4 cell counts of more than 200 cells per microliter were fairly evenly split among the three study arms. Eleven patients didn't receive any vaccine. The two alternative regimens were well tolerated, with "no safety signal and no effect on CD4 cell count or viral load," the researchers report.
The main outcome measure was the percentage of responders at week 28, defined as patients with hepatitis B surface antibody (anti-HBs) of at least 10 mIU/mL in patients who received at least 1 dose of vaccine. A total of 396 patients had available anti-HBs titers at week 28.
The researchers say there was a significant increase in the response rate 1 month after the last dose of HBV vaccine in patients in the IM40X4 group compared with the standard dose group (82% vs. 65% with IM20X3). The proportion of responders at week 28 with the ID4X4 regimen was also higher in comparison to the standard regimen (77% vs. 65%).
In addition, with the IM40X4 regimen, a high seroconversion rate was evident as early as week 12 (72%), the researchers report.
Moreover, 74% of patients in the IM40X4 group had anti-HBs titers of at least 100 mIU/mL, which is considered to be fully protected and associated with long-term response. In the IM20X3 and ID4X4 groups, these percentages were 41% and 53%, respectively.
Dr. Launay predicts that the four intramuscular double doses will become "the recommended regimen" for patients with HIV infection.