Study Finds Babies Are Born With Greater Natural Resistance to HIV
A study published in the journal Nature Medicine has found that boys are born with greater natural resistance to HIV than girls. The discovery, led by researchers led by Philip Goulder of the University of Oxford, UK, offers new insights into gender differences in the immune system.
According to the World Health Organization, about 1.3 million women and girls living with HIV become pregnant each year, and rates of transmission of the virus to a child during pregnancy, labor, delivery, or breastfeeding can range from 15% to 45% without preventive measures. Goulder’s study, which assessed 284 infants in KwaZulu-Natal, South Africa, found that transmission of HIV to males was 50% less common than to females.
Goulder and his team gave infants a combination of HIV drugs, known as combination antiretroviral therapy, from birth. They found that the men who became infected had lower levels of the virus in their blood, and four of them have now achieved HIV cure/remission, maintaining undetectable levels of the virus even without treatment.
Research shows that this gender disparity is linked to lower levels of activated CD4 T cells in male fetuses, making it harder for the virus to survive. CD4 T cells are critical to the immune system and are targeted by HIV during infection.With fewer of these cells, HIV spreads more slowly.
“If the virus is accidentally transmitted to a person, it is difficult for them to survive because there are not enough activated CD4 T cells to sustain the infection,” Goulder explains.
The study, which began in 2015 and has so far included 315 babies, is believed to be one of the largest cohorts of its kind in the world. Nomond Bengu, a co-author of the study at Queen Nandi Regional Hospital in KwaZulu-Natal, says access to mother and baby during birth is vital to understanding the “founder virus” and how children recover/remit.
Antibodies
Despite these promising results, some boys still have very low levels of HIV antibodies, and the long-term consequences are unclear. However, a similar case of an African child has shown that it is possible to remain untreated and without detectable virus for 15 years.
Mark Cotton, Emeritus Professor in the Department of Paediatrics and Child Health at Stellenbosch University, says the study provides a significant boost to efforts to control HIV through interventions in the immune system, highlighting the importance of studying children in efforts to control and eliminate HIV.
The study advances knowledge about HIV treatment and remission and could have important implications for treatment strategies for the 39 million people living with HIV worldwide.