Non-Infected Babies Born to HIV Mothers Have Reduced Immunity to Measles

The results of this study suggest that babies born to HIV mothers would not be able to neutralize the measles virus as effectively and would lose protection sooner than babies born to healthy mothers. These babies would therefore be much more likely to succumb to measles and/or pass the virus on to other children, making their early immunization vital, according to Dr. Lars Smedman of the Department of Paediatrics at Karolinska University Hospital, Stockholm, Sweden.

Non-infected babies born to HIV-positive mothers should be vaccinated early against measles to avoid acquiring the virus or passing it on to others. A study published in the November issue of Acta Paediatrica found that even if babies are born without HIV, their maternally derived protection against measles may be impaired by their mother's positive HIV status.

Smedman and colleagues compared blood serum samples from 10 babies one to four months of age who were born to HIV mothers, but had not acquired the infection, to 10 healthy babies born to mothers without HIV. The mothers ranged in age from 26 to 35 years and were all immigrants who originated from Ethiopia, the Ivory Coast, Uganda, Kenya, and Thailand. Their viral loads ranged from less than 20 to 8,870, and their CD4 cell counts from 237 to 754.

Nine of the mothers gave birth by planned or emergency caesarean, with only one vaginal birth, and the gestational age of the babies ranged from 32 to 41 weeks. "We used a new cell ELISA technique to demonstrate how the serum samples drawn from the infants would inactivate the measles virus," explained Smedman. He added that this test found statistically significant differences between the maternal antibodies received by the two sets of babies and revealed that the non-infected babies born to HIV-positive mothers had weaker protection. This was because the antibodies normally produced by the mother to help protect her baby from measles had lost their effectiveness due to the mother's HIV-positive status.