Bill Gates, the Microsoft Corp. co-founder and billionaire philanthropist, has become, for better and worse, a central character in the story of Covid-19. The good news: The Bill & Melinda Gates Foundation has pledged more than $350 million to fight the disease, including funds for vaccine manufacturing efforts at AstraZeneca, Johnson & Johnson, and Novavax. The bad news: Gates has been vilified by anti-vaxxers and other conspiracy theorists who claim he seeded the virus for his own nefarious purposes.

Gates says he's optimistic about the world's chances of seeing through the wilder theories and of beating the coronavirus, too. His remarks have been condensed and edited for clarity.

How confident are you we'll have a working vaccine that can be widely distributed by the end of 2020?

Well, the initial vaccine won't be ideal in terms of its effectiveness against sickness and transmission. It may not have a long duration, and it will mainly be used in rich countries as a stopgap measure.