The Bill and Melinda Gates Foundation has pledged $287m (£155m) in a bid to speed up the development of a vaccine for the HIV/Aids virus.
It is the Gates Foundation's biggest ever investment in HIV and Aids
The money is being split into 16 grants for science teams across the world - with the aim that they work more collaboratively on new approaches.
All the recipients have had to agree to share their findings - even if they had been working on competing projects.
More than 40 million people are believed to be infected with HIV/Aids.
While dozens of different potential vaccines have been trialled in the 25 years since the HIV virus was first identified, scientists have struggled to develop an effective vaccine.
This is because of the virus's ability to mutate and attack the human immune system - the very thing that vaccines try and stimulate to ward off infections.
"Unfortunately, developing an effective HIV vaccine has proven to be tremendously difficult, and despite the committed efforts of many researchers around the world, progress simply has not been fast enough," said Dr Nicholas Hellmann, of the Gates Foundation's HIV, TB and reproductive health programme.
He said the aim of the grant funding is to identify the most innovative approaches in vaccine research and then direct future efforts towards those ideas.
The 16 grants are being divided between 165 investigators in 19 countries - some of whom are well-known in the area of HIV/Aids research and some who are lesser known.
One of the projects being funded is research to isolate a large number of antibodies from humans and animals, including llamas, to see if they can neutralise HIV.
Another project will try to use viruses related to smallpox as potential vaccines.
The researchers will be expected to share their findings and compare their results with others to ensure a more coordinated approach to scientific research.
This is the foundation's largest-ever investment in HIV and Aids research, Dr Helmann said.
The foundation says it is also developing global access plans to ensure that any discoveries from the research are accessible and affordable in developing countries.