Bill Gates has called for a new $1 billion World Health Organisation Pandemic Task Force to run "germ games" in preparation for future pandemics caused naturally or by bioterrorists.
The Microsoft co-founder's comments came in the second part of an interview for the Policy Exchange think tank with former UK health secretary Jeremy Hunt.
In the first part, Mr Gates said that rapid innovation was needed to meet the world's 1.5°C climate target.
In the sequel he was equally candid, condemning the world's lack of preparedness for the coronavirus pandemic.
“It was 2015 that I gave the Ted talk and wrote a number of papers titled, 'We're not ready for the next pandemic'," he said.
"And sadly that was a better forecast of what would happen than anyone would have wished for. The economic damage, the deaths – it's been completely horrific."
Mr Gates said a "new way of doing the vaccines" must be found and that the diagnostics were never "up and running in order to achieve what at least Australia and New Zealand showed, that competent management could keep the death rate down pretty dramatically".
He said he hoped that in the next five years he would be able to write a book that said the world was prepared for pandemics, but getting to this happier state would be costly.
"It'll take probably about a billion a year for a pandemic taskforce at the WHO level, which is doing the surveillance and actually doing what I call 'germ games'," Mr Gates said.
These games would involve role-playing situations where terrorists could seek to harness biological weapons to inflict global damage.
Mr Gates gave the example of a bioterrorist bringing smallpox to 10 airports, where advances in medical sciences should give the world the tools to "do dramatically better".
He said preparation for pandemics would bring a broader benefit to social health.
“The nice thing is a lot of the R&D we need to do to be ready for the next pandemic are things like making vaccines cheap, having big factories, eradicating the flu, getting rid of the common cold, making vaccines just a little patch you put on your arm, things that will be incredibly beneficial even in the years when we don't have pandemics."
Mr Gates said he would continue to advocate the preparedness message in years to come and believes people will willingly receive it after the loss "trillions of dollars and millions of lives".
"[They] expect their governments not to let that happen again,” he said.