evidence: 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.