Fear is the greatest ally of human scourges. A former American president famously said during the Depression that the only thing to be feared was fear itself. That could easily be adapted to the fight against HIV/Aids. Fear, ignorance, denial and discrimination remain obstacles to global efforts to contain the disease through openness, education and compassion. Worse, some of it is state-sanctioned, with more than 50 countries maintaining laws and restrictions that effectively marginalise people with HIV. It is good, therefore, that first the world's most powerful country and then its most populous have finally abandoned an egregious and symbolic example of fear and discrimination - bans on HIV-positive visitors. Earlier this year, US President Barack Obama dropped a 22-year restriction 'rooted in fear rather than fact'. Yesterday, it was President Hu Jintao who was commended by the UN and world health officials after China revoked a two-decade ban.

The decision came days before travellers from around the world arrive for Shanghai's World Expo. Beijing has temporarily lifted the ban for major events in the past. It made administrative sense as well as enlightened policy to end it. Indeed, a legal affairs official said it had impeded the country's hosting of international events.

The new rules bar foreigners with serious psychiatric illnesses, infectious pulmonary tuberculosis or 'other infectious diseases that may constitute a major threat to public health'. They do not make it clear whether HIV should be declared, leaving officials with some leeway on how to apply them. We trust the legal official is right to insist that HIV/Aids will no longer be a bar to entry.