On Sunday, U.S. researchers reported that a baby girl has been effectively cured of HIV infection with the use of standard antiretroviral drugs. This is an exciting development giving hope that AIDS, which is caused by HIV, may be cured in young children, but there are many steps to be taken before that can happen.
In 2010 a girl, whose identity has not been revealed, was infected by HIV at birth because her mother was carrying the infection. Within 30 hours of being born, the baby was treated with potent antiretroviral therapy that consists of three different drugs. The treatment was continued and in under a month the baby’s infection dropped significantly and remained so for further 18 months. Then, for reasons unknown, the mother stopped the baby’s treatment.
Usually stopping the treatment gives the infection a chance to flare up. When doctors saw the baby again after more than five months, they were expecting that HIV test would be positive. Hannah Gay, a pediatric HIV specialist who cared for the baby, told The Guardian, “All the tests came back negative, very much to my surprise.”
It is not clear why this happened. Rolando Barrios, a pharmacologist at the British Columbia Centre for Excellence in HIV/AIDS, says: “It is possible that an earlier intervention stopped HIV from lodging into the immune cells.” Barrios told The Hindu that sometimes there is a 48-hour window after catching the infection to stop its irreversible spread.
HIV infection takes hold in the human body by infecting long-lived white blood cells called CD4. If antiretroviral drugs are given early enough, they can block HIV from infecting CD4 cells. But if it is too late for that, these drugs can only curtail the replication of the virus. Which means that, on stopping the drug treatment, the virus becomes free to start replicating again.
In the reported case an early intervention may have stopped the spread and continued treatment reduced whatever infection was left. But very little can be said unless this can be repeated in many babies.
Doctors found out that the girl was rid of HIV, as far as can be detected, only because the drug treatment was stopped for many months. But this should not encourage others to stop their treatment, stressed the researchers. “We must be cautious about this singular result”, says Barrios.
Current treatments, if given at the appropriate time, can already stop up to 98% babies from being infected by their HIV-infected mothers. So of the 330,000 babies born with HIV annually, many can already be saved from the infection if these drugs are made available. Nonetheless, this case is remarkable because it opens a new line of investigation.
First published on thehindu.com.
UPDATE: There are questions being raised whether the baby was infected with HIV or not. The Hindu reports that the child wasn’t carrying any HIV antibodies. These should’ve been present even if the infection had been cured. Researchers suggest that some HIV particles can disappear from the newborn within four months without causing infection.