The HIV and Aids research community was stunned today, as it emerged that 108 delegates to Melbourne’s 20th International AIDS Conference were on the Malaysian Airlines jet which was apparently shot down over Ukraine last night.

The event describes itself as ‘the premier gathering for those working in the field of HIV’, as well as policy makers, people living with HIV and other individuals committed to ending the pandemic. The dead include Dutch HIV researcher and former International AIDS Society President Dr Joep Lange, along with his wife and collaborator Jacqueline van Tongeren; and World Health Organisation media relations coordinator Glenn Thomas.

Lange had been involved in HIV research and treatment since 1983, and worked in particular on pivotal trials in antiretroviral therapy and on the prevention of mother-to-child transmission of HIV.

The conference, which is to go ahead as planned from Sunday, is set to host a number of other high profile people, including former US president Bill Clinton and Sir Bob Geldof. All 298 people on board the aircraft died when it was shot down from 33,000ft while it was en route from Amsterdam to Kuala Lumpur; over half were Dutch. The flight was downed over the village of Grabovo, part of the area of Ukraine controlled by pro-Russia separatists. The European air traffic control body, Eurocontrol, said Ukrainian authorities had banned aircraft from flying at 32,000ft or below. All civilian flights have now been barred from the area of eastern Ukraine

UNAIDS executive director Michael Sidibé was quick to express his condolences on Twitter, adding that his thoughts and prayers were with the victims’ families, while the City of Melbourne cancelled a planned docklands fireworks display in their memory. The Sidney Morning Herald’s digital editor Bevan Shields wondered ‘how many more innocent people will die due to the loss of 100 brilliant minds.’

Although it is too soon to be sure exactly what happened, the US said it had intelligence showing a surface-to-air missile was used. Both sides in the current Ukraine crisis blamed one another, but the US has criticised Russian arming of rebels in Ukraine.