Revaccinating with a double dose of the hepatitis B virus (HBV) vaccine is effective in at least half of people with HIV who did not respond to an initial round of immunization injections, say researchers of a study published in the January 15 issue of the Journal of Infectious Diseases.
HBV vaccination is recommended for all people living with HIV who’ve never been infected with HBV. This vaccination is critical, because people who are infected with both HBV and HIV are at much greater risk of illness and death than people infected with only one of the two viruses. In people who are HIV negative, more than 90 percent of people given the HBV vaccine will develop antibodies that protect them from HBV infection. Unfortunately, people living with HIV respond far less well, with only 50 percent or fewer developing effective antibodies.
Theodora E.M. de Vreis-Sluijs, MD, of the department of internal medicine at the Erasmus Medical Center in Rotterdam, The Netherlands, and her colleagues enrolled 144 people with HIV who had not previously responded to standard HBV vaccination. Seventy-five percent of the participants were male, and the majority were on antiretroviral therapy and in good health at the time of the study. Vreis-Sluijs’s team vaccinated the participants with 20 µg of HBvaxPro, twice the normal dose, by intramuscular injections, followed by two further injections given one and two months respectively after the first dose.
The second round of higher-dose injections were effective, with 51 percent of the participants developing an effective antibody response to the vaccine. Two factors, being female or of younger age, increased the likelihood of a person’s developing immunity to HBV.
Vreis-Sluijs’s team states that they cannot be certain if it was a second round of vaccination or the use of a double dose that contributed to the favorable response rate. Previous studies using either higher doses of the vaccine during initial vaccination, or rechallenging using the standard dose have been mixed. The researchers are encouraging further research to answer this question.
