HIV-Exposed Infants Have Reduced Antibodies Against Diseases

Infants with prenatal exposure to HIV are born with fewer antibodies to fight diseases such as hepatitis B and whooping cough, according to a study in South Africa that doctors say could lead to expansion of vaccination programs to include HIV-infected pregnant women.

Of infants exposed to HIV before birth without becoming infected themselves, 17 percent had antibody levels thought to protect against Haemophilus influenza type B, or HiB, compared with 52 percent of infants without exposure, researchers said today in the Journal of the American Medical Association. Twenty-one percent of those exposed had antibodies against hepatitis B compared with 54 percent of unexposed babies.

The study confirms what doctors had already thought: that babies exposed prenatally to HIV are born with less protection against infections, said Michael Brady, chairman of the Department of Pediatrics at National Children’s Hospital in Columbus, Ohio, who wasn’t involved in the research.

“Maybe we should start developing a vaccine program for HIV-infected women to make sure that infants have the best opportunities to get mom’s antibodies at high levels,” Brady said in a telephone interview on Feb. 4. Brady is also chairman of the committee on infectious diseases for the American Academy of Pediatrics, based in Elk Grove Village, Illinois.

Women with HIV have lower antibody levels to some infections and transfer less protection to their babies, said Christine Jones, the lead author of the study.

Vulnerability Seen

The research shows why infants who were exposed to HIV without catching that virus might be vulnerable to other infections, Jones, a clinical research fellow in pediatrics at Imperial College London, said in an e-mail on Feb. 6. The pattern changed after vaccination, she said.

“Once the HIV-exposed, uninfected babies received their routine vaccinations, they had antibody levels similar to, or higher than, HIV unexposed infants, meaning that they were likely to be well protected by vaccination,” Jones said.

More research is needed to establish whether babies exposed prenatally to HIV could be better protected against infections through earlier vaccination, or through vaccine shots given to mothers before the children are born, the researcher said.

Before vaccine recommendations can change, more studies are also needed to show that boosting antibody levels in these babies actually prevents them from developing these diseases, Jones said.

Makers of vaccines include New York-based Pfizer Inc., Paris-based Sanofi-Aventis SA, London-based GlaxoSmithKline Plc and Punjab, India-based Panacea Biotec Ltd.

109 Mothers

In the study, researchers from Imperial College London and Stellenbosch University in Stellenbosch, South Africa, included 109 mothers who were either HIV infected or uninfected. The scientists measured antibody levels in the mothers at delivery and in the babies at birth. The researchers also looked at how the infants responded to vaccinations four months after they had received the vaccines.

The study showed that HIV-exposed infants who weren’t infected with the disease had lower levels of antibodies to whooping cough, tetanus, and pneumococcus or bacterial pneumonia. HIV-positive mothers had lower levels of antibodies to HiB and pneumococcus, and not to whooping cough or tetanus, the researchers found. HiB can cause meningitis and pneumonia.

Bruce Hirsch, an attending physician at North Shore University Hospital in Manhasset, New York, said while vaccinations may help, the priority should be getting women’s HIV under control.

“They need to get their HIV under control as much as possible to decrease the frequency of transmitting HIV to their babies and to improve their own health and improve their own immune power,” Hirsch said in a telephone interview on Feb. 4.

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