Fischman: More and more data is coming out about long COVID: serious physical and mental effects that can last half a year after people first get infected. Fischman: Let’s talk about the Delta variant. Lewis: The Delta variant is definitely concerning—particularly for unvaccinated people. We don’t yet know how well the Johnson & Johnson vaccine works against the Delta variant, but it’s likely to provide some protection. Now this expertise is helping with COVID vaccines.