HIV-Infected Children Living in Central Africa Have Low Persistence of Antibodies to Vaccines Used in the Expanded Program on Immunization

Abstract

BackgroundThe Expanded Program on Immunization (EPI) is the most cost-effective measures to control vaccine-preventable diseases. Currently, the EPI schedule is similar for HIV-infected children; the introduction of antiretroviral therapy (ART) should considerably prolong their life expectancy.Methods and Principal FindingsTo evaluate the persistence of antibodies to the EPI vaccines in HIV-infected and HIV-exposed uninfected children who previously received these vaccines in routine clinical practice, we conducted a cross-sectional study of children, aged 18 to 36 months, born to HIV-infected mothers and living in Central Africa. We tested blood samples for antibodies to the combined diphtheria, tetanus, and whole-cell pertussis (DTwP), the measles and the oral polio (OPV) vaccines. We enrolled 51 HIV-infected children of whom 33 were receiving ART, and 78 HIV-uninfected children born to HIV-infected women. A lower proportion of HIV-infected children than uninfected children had antibodies to the tested antigens with the exception of the OPV types 1 and 2. This difference was substantial for the measles vaccine (20% of the HIV-infected children and 56% of the HIV-exposed uninfected children, p<0.0001). We observed a high risk of low antibody levels for all EPI vaccines, except OPV types 1 and 2, in HIV-infected children with severe immunodeficiency (CD4+ T cells <25%).Conclusions and SignificanceChildren were examined at a time when their antibody concentrations to EPI vaccines would have still not undergone significant decay. However, we showed that the antibody concentrations were lowered in HIV-infected children. Moreover, antibody concentration after a single dose of the measles vaccine was substantially lower than expected, particularly low in HIV-infected children with low CD4+ T cell counts. This study supports the need for a second dose of the measles vaccine and for a booster dose of the DTwP and OPV vaccines to maintain the antibody concentrations in HIV-infected and HIV-exposed uninfected children.

Impaired Humoral Response to Vaccines among HIV-Exposed Uninfected Infants

“…Low responsiveness to measles vaccine in HIV-infected children has been associated with nutritional status rather than with HIV infection (33). This cannot be applied to our findings for the HEU infants concerning hepatitis B and DTP vaccines, as there were no children with a poor general health status in our study.…”

Whole-Cell Pertussis Vaccine Induces Low Antibody Levels in Human Immunodeficiency Virus-Infected Children Living in Sub-Saharan Africa

“…The study was conducted in accordance with the Declaration of Helsinki. The detailed study design has been reported previously (21). Briefly, children were included in the study if they had received at least a primary vaccine series of three doses of the DTwP vaccine, as certified by their immunization card.…”

Assessment of the Epidemiology and Burden of Measles in Southern Mozambique

“…20,21 The HIV infection is also considered to be an important factor contributing to primary and secondary measles vaccine failure. 22,23 Thus, there is a need to characterize the local epidemiology of measles in regions with a growing HIV prevalence, to design new control strategies to protect children before the age of vaccination, and to overcome vaccine failure. 12 Monitoring for measles in Mozambique is conducted through a hospital-based Weekly Information Bulletin System (Boletim Epidemiológico Semanal -BES) notification from health facilities.…”