THE latest dispatch from the war on HIV, the “Global AIDS Update 2016”, just published by UNAIDS, the UN agency responsible for combating the virus, brings qualified good news. Last year, it estimates, there were 1.1m AIDS-related deaths, down from a peak of 2m in 2005 and a figure of 1.2m in 2014. Last year also saw 2.1m new infections, down from a peak of 3.4m in 1998 but up from 2014’s estimate of 2.0m.

By the end of 2015 some 17m people were taking anti-retroviral (ARV) drugs—2m more than the target number for that year, set by the UN in 2011. This accounts for the falling death rate. Some hoped the drug roll-out might also lead to an increased fall-off in the rate of new infections. That hope was based on the idea, experimentally demonstrated at small scale among cohabiting couples, that taking ARVs makes an infected individual less likely to pass the virus on. There is, though, no sign of such an acceleration in the downward trend of new infections. This year’s uptick aside, it has remained fairly steady since the turn of the century, despite the fraction of infected people on ARVs having risen from 3% in 2000 to 46% in 2015.

The next UN target is that, by 2020, 90% of those infected should have been diagnosed and know their status, 90% of those so diagnosed should be on ARVs, and 90% of those on ARVs should have suppressed viral loads. That is ambitious, but history suggests those in the field will rise to the challenge.