A small group of adults given rapid drug treatment after HIV infection no longer need drugs to keep the virus in check. Last week, a baby was reported to have been "functionally cured" of HIV after receiving a three-drug regime of ARVs almost immediately after birth. Early treatment seems crucial, but does not guarantee success.
Asier Sáez-Cirión of the Pasteur Institute's unit for regulation of retroviral infections in Paris analysed 70 people with HIV who had been treated with antiretroviral drugs (ARVs) between 35 days and 10 weeks after infection – much sooner than people are normally treated.
All of the participants' drug regimes had been interrupted for one reason or another. For example, some people had made a personal choice to stop taking the drugs, others had been part of a trial of different drug protocols.
Most of the 70 people relapsed when their treatment was interrupted, with the virus rebounding rapidly to pre-treatment levels. But 14 of them – four women and 10 men – were able to stay off of ARVs without relapsing, having taken the drugs for an average of three years.
On average, the 14 adults have been off medication for seven years. One has gone 10-and-a-half years without drugs. "It's not eradication, but they can clearly live without pills for a very long period of time," says Sáez-Cirión. The 14 adults still have traces of HIV in their blood, but at such low levels that their body can naturally keep it in check without drugs.
Sáez-Cirión warns that rapid treatment doesn't work for everyone, but the new study reinforces the conclusion that early intervention is important.
"There are three benefits to early treatment," says Sáez-Cirión. "It limits the reservoir of HIV that can persist, limits the diversity of the virus and preserves the immune response to the virus that keeps it in check."
Further analysis confirmed that the 14 adults were not "super-controllers" – the 1 per cent of the population that are naturally resistant to HIV – since they lack the necessary protective genes. Also, natural controllers rapidly suppress their infections, whereas these 14 mostly had severe symptoms which led to their early treatment. "Paradoxically, doing badly helped them do better later," says Sáez-Cirión.
The researchers are trying to identify additional factors that could explain why early intervention only works on some people, hopefully extending the scope for more functional cures. "This whole area is fascinating, and we've been looking very closely at issues of early initiation of treatment, and the potential for functional cures," says Andrew Ball, senior adviser on HIV/AIDS strategy at the World Health Organization in Geneva.
"The big challenge is identifying people very early in their infection," says Ball, adding that many people resist testing because of the stigma and potential discrimination. "There's a good rationale for being tested early, and the latest results may give some encouragement to do that," he says.