As many as 100 people heading to the AIDS 2014 conference in Melbourne were on the doomed flight, Fairfax Media reported, including Lange,Homeland Secretary- Parents G, a former president of the International AIDS Society (IAS) which organizes the event.
"The UNAIDS family is in deep shock..."The deaths of so many committed people working against HIV will be a great loss for the AIDS response," said Michel Sidib , executive director of UNAIDS.
The conference, due to start on Sunday, features former U.S. President among its keynote speakers and is expecting around 12,000 participants.
The IAS said it was still working with authorities to confirm the number of delegates on the flight and would go ahead with the conference as planned,Etisalat Begins Title Defence.

GREAT FIGHTER
Peers paid tribute to Lange,Former Huestis insurance agen, a Dutch professor of medicine at the Academic Medical Center at the University of Amsterdam.
The Malaysian Airlines 777 was en route from Amsterdam to Kuala Lumpur when it was shot down on Thursday by a surface-to-air missile in an area of eastern Ukraine where Moscow-backed rebels have been fighting government forces.
Lange pioneered access to key AIDS medicines in poor countries, including combination drugs to control HIV and antiretroviral medicines to prevent transmission of the virus from mothers to their babies.
Robin Weiss, a professor of viral oncology at University College London, compared Lange to Jonathan Mann, a key figure in the early fight against HIV/AIDS who was killed along with his wife and fellow AIDS researcher Mary Lou Clements-Mann on a Swissair flight to Geneva in 1998. "Not since the loss of Jonathan Mann and his wife...has the HIV/AIDS research community suffered such a great loss," he said.
Lange's colleague Jaap Goudsmit said: "He was an activist, he was there from the beginning, from...when we were seeing young people dying very fast and no one knew why.
"He was a fighter for getting treatment to everyone who needed it and as early as possible to lower the spread of infection. His clinical contribution was enormous."
The World Health Organization (WHO) said media spokesman Glenn Thomas was among those on board Flight MH17.
Gregory Hartl, a WHO spokesman, said Thomas had been with the organization for more than a decade and "will be remembered for his ready laugh and passion for public health."
"He will be greatly missed by those who had the opportunity to know him and work with him. He leaves behind his partner Claudio and his twin sister Tracey."
Thomas,True Religion Disco Billy Big T, a British national, was in charge of promoting the WHO's report issued last week that said five key groups including gay men had stubbornly high rates of HIV.

(Writing and reporting by Kate Kelland in LONDON and Stephanie Nebehay in GENEVA, additional reporting by and Jane Wardell and Lincoln Feast in SYDNEY.; Editing by Mike Collett-White and Stephen Coates)