HIV-positive children who do not have severe immunosuppression or HIV-related symptoms respond well to vaccination against hepatitis A virus, according to a Brazilian study published in the August 15th edition of Clinicial Infectious Diseases. The investigators also found that vaccination against hepatitis A does not adversely affect viral load.
On the basis of their findings, the Brazilian investigators recommend routine hepatitis A vaccination for those HIV-positive children living in areas with a high prevalence of hepatitis A.
Liver disease has emerged as a major cause of illness and death amongst HIV-positive individuals since highly active antiretroviral therapy (HAART) became available. There is a high prevalence of hepatitis A in San Paolo, Brazil and it is recommended that children are vaccinated against it.
However, there are a lack of data about immune response to and tolerability of hepatitis A vaccine in HIV-positive children.
Because of this, investigators designed a study involving 32 HIV-positive children and 27 HIV-negative children to assess the immunogenicity and tolerability of hepatitis A vaccine (Havrix). The investigators also included a control arm of HIV-positive children who did not receive vaccination against hepatitis A to assess the impact of the vaccine on CD4 cell count and viral load.
The mean age was 5.5 years for the hepatitis A-vaccinated HIV-positive children and 5.1 years for the HIV-negative children who received the vaccine. None of the HIV-positive children recruited to the study had AIDS, although 38% had symptoms indicative of HIV infection. A total of 29 HIV-positive children were receiving HAART and eleven had a viral load below 400 copies/ml. None of the children in the study were infected with hepatitis B or C virus.
CD4 cell count and viral load were measured in HIV-positive children four to eight weeks before they received the first and second dose of hepatitis A vaccine. These tests were also performed on 31 HIV-positive children (mean age 5.8 years) who did not receive the vaccine.
The first dose of hepatitis A vaccine produced antibodies against the virus in 87% of HIV-positive and 72% of HIV-negative children. After the second dose, 100% of children in both groups had antibodies against hepatitis A with adequate titre levels.
Six HIV-positive and three HIV-negative children experienced mild and transient systemic side-effects after receiving the vaccinations.
Mean HIV viral load did not vary in the vaccinated HIV-positive children, however two children who had an undetectable viral load before vaccination experienced a transient blip between the first and second doses before their viral load became undetectable once again.
They note that the 100% response to hepatitis A vaccine observed in HIV-positive children in this study was significantly better than the response to the vaccine observed in HIV-positive adults and are unable to explain this.
They conclude, "we have shown that HIV-infected children without severe symptoms or immunosuppression can respond to hepatitis A vaccine as well as non-HIV-infected children, with low rate of adverse events." They recommend routine vaccination in areas with a high hepatitis A prevalence and add, "vaccination would help to prevent a further burden to the liver of those children and adolescents already exposed to a variety of hepatotoxic drugs."
Gouve AFTB et al. Immunogenicity and tolerability of hepatitis A vaccine in HIV-infected children. Clin Infect Dis: 41, 544 - 548, 2005.