Scientists found that babies born to HIV-infected mothers had significantly lower levels at birth of antibodies against a range of bacterial infections, such as whooping cough and tetanus than babies whose mothers don’t have the virus.
The finding, by scientists from Imperial College London and South Africa’s Stellenbosch University may help explain why babies without HIV but whose mothers do have the virus have a higher risk of illness and early death.
"Our data contribute to a potential explanation for the higher morbidity and mortality observed among African HIV-exposed infants," said Imperial College’s Christine Jones.
Births of HIV-positive babies have dropped dramatically in the past decade thanks to medications that mothers can take during pregnancy to prevent transmission. But infectious diseases still kill six million under-fiver year olds every year, the team noted. And poorer country’s growing numbers of HIV-exposed but uninfected babies are an especially vulnerable group, they added.
While a lot of their vulnerability to infectious diseases is because of social and economic conditions, researchers found, it's also possible that "altered immune responses might contribute to the high morbidity and mortality observed in HIV-exposed uninfected infants."
"Our data highlight the need for larger prospective studies to determine whether the lower antibody levels in HIV-exposed infants at birth translate into increased morbidity from vaccine-preventable infections," scientists concluded.
The study looked at 109 HIV-infected and uninfected mothers at a community health centre in Khayelitsha, growing part in Cape Town, South Africa. The findings have been published in the Journal of the American Medical Association
An HIV-infected mother can pass the virus to her baby during pregnancy, birth and delivery, or breastfeeding. Without treatment, about 15-30 per cent of babies born to HIV positive mothers will get infected with HIV during pregnancy and delivery, according to figures from Aids charity, Avert. Another 5-20 per cent will become infected through breastfeeding.
In 2009, about 400,000 children under 15 were infected with HIV, mainly through mother-to-child transmission. About 90 per cent of these infections were in Africa.
In richer countries mother-to-child transmission has been mostly wiped out with voluntary testing and counselling, access to anti-retroviral therapy, safe birth practices, and the widespread availability and safe use of breast-milk substitutes. If these interventions were used worldwide, they could save the lives of thousands of children each year.