Bill Gates has issued some pretty big warnings in recent years — about the next pandemic or avoiding a "climate disaster" — but the billionaire says he's actually very optimistic about the future.

So let's stay the course." Gates is also still bullish on the future of vaccine development, even with the appointment of Robert F. Kennedy Jr. all but sewn up.

So let's stay the course." Gates is also still bullish on the future of vaccine development, even with the appointment of Robert F. Kennedy Jr. all but sewn up.

For all the complaints about the Gates Foundation, Gates himself seems to take the long view. And his optimism about the ability of other philanthropists to pick up where he has left off is helpful.

So let's stay the course." Gates is also still bullish on the future of vaccine development, even with the appointment of Robert F. Kennedy Jr. all but sewn up.

So let's stay the course." Gates is also still bullish on the future of vaccine development, even with the appointment of Robert F. Kennedy Jr. all but sewn up.