The money will be used to accelerate basic scientific research – from software to hardware to yet-undiscovered techniques – they hope will ultimately lead to breakthroughs, the way the microscope and DNA sequencing have in generations past.
The goal, which they are unlikely to live to see accomplished, is to “cure, prevent or manage all disease” in the next 80 or so years.
They acknowledge that this might sound crazy, but point to how far medicine and science have come in the last century – with vaccines, statins for heart disease, chemotherapy, and so on – following millennia with little progress.
Zuckerberg, who founded the social networking site, said: “So if you even just assume that we’ll be able to continue to make progress on that same trajectory, then that implies that by the end of this century we will have been able to solve most of these types of things,”
He and Ms Chan have spent the past two years speaking to scientists and other experts to plan the endeavour.
He emphasised “that this isn’t something where we just read a book and decided we’re going to do”.
The commitment includes $600 million (£462 million) to fund a new research centre in San Francisco where scientific and medical researchers will work alongside engineers on long-term projects.
The goal is not to focus narrowly on specific ailments, such as bone cancer or Parkinson’s disease, but rather to do basic research.
“I’ve been with families where we’ve hit the limit of what’s possible through medicine and science,” Ms Chan said.
“I’ve had to tell families devastating diagnoses of leukaemia, or that we just weren’t able to resuscitate their child.”
Mr Zuckerberg and Ms Chan hope that their effort will inspire other far-reaching efforts and collaboration in science, medicine and engineering, so that basic research is no longer relegated to the margins.
“We spend 50 times more on health care treating people who are sick than we spend on science research (to cure) diseases so that people don’t get sick in the first place,” Mr Zuckerberg said.
“It’s very hard with today’s science funding to build a team to work on scientific problems that are like what you would find at a world-class technology company, that are that scale, So that’s something I think we can concretely help out with.”
He added that the approach reflects a belief that “people are always going to suffer from disease so therefore we should focus on treating people who are sick”.
Eric Lander, a professor of biology at the Massachusetts Institute of Technology and director of the Broad Institute at MIT and Harvard, said he has had some 20 conversations with Mr Zuckerberg and Ms Chan over the past year about the initiative and called their goal “the right kind of goal for thinking about that kind of time frame”.
He is not involved with the project itself, but expressed confidence in it.
“Mark has brought new models to industry with Facebook,” he said, adding that while organisations like the National Institutes of Health are “fantastic”, there is “no point in replicating what existing models do”.