HIV-infected infants respond poorly to childhood vaccination

It is known that HIV-infected children who do not receive appropriate antiretroviral drugs experience immune depression, and may become susceptible to infectious diseases that would otherwise be prevented by childhood immunization.

It is therefore important to find out to what extent HIV-infected children are able to generate adequate levels of antibodies following routine childhood immunizations.

A paper published online this week in PLoS ONE describes the results of a cross-sectional study carried out amongst 18-36 month-old children born to HIV-infected mothers and living in Central Africa. The study suggested that immuno-suppressed HIV-infected children have a low persistence of antibodies to the vaccines of the Expanded Program on Immunization (EPI, WHO).

The study was conducted in Cameroon and the Central African Republic by pediatricians, epidemiologists, bacteriologists and virologists, and coordinated by the Institut Pasteur (Paris, France) through its International Network, particularly the institutes based at the Pasteur Center in Yaoundé and at the Institut Pasteur in Bangui.

The researchers found that antibody levels to measles vaccine was particularly low amongst children who were HIV infected, and that antibody levels to vaccine amongst HIV-uninfected children born to HIV-infected mothers were lower than expected. This latter finding raises the possibility that HIV exposure during pregnancy might influence the response to EPI vaccines in the first weeks of life. These results suggest that children living with HIV may need an adapted EPI vaccine schedule.