Do the variants matter?

The Pfizer, Moderna, and Johnson & Johnson vaccines appear to provide robust protection against the known variants, but studies nonetheless suggest they may be 10 to 20 percent less effective. And as the virus continues to rip through much of the world, it can develop new mutations and variants that make vaccines less effective. Less than a quarter of the global population has been infected so far, and many poor countries aren’t expected to have widespread access to vaccines until 2023.