"Our Foundation is proud to partner with you and I'm pleased to announce today that we will pledge $100 million towards this effort," Melinda Gates said at the international video conference.
She attended a virtual pledging event, Coronavirus Global Response, organised by the European Union and its partners, in a bid to to raise 7.5 billion euros in initial funding to kick-start the global cooperation.
Microsoft co-founder Bill Gates previously described US coronavirus testing data as "bogus" because of its inaccuracy and slow turnaround.
According to the World Health Organisation, that declared the coronavirus a pandemic in March, the virus has infected 3,435,894 people and killed 239,604, as of Monday 5:00 p.m. CEST.