Eight months later, what we know — and don't know — about Covid-19

As hard as it may be to believe, the world has been living with Covid-19 for around eight months now. In that time, there's a lot we have learned about the coronavirus that causes it, including how virus particles on the surface of objects — known as fomites — probably aren't a major route of transmission, and how people without symptoms can spread the virus, two facts that were unknown or disputed early on in the pandemic. But there's still a lot we have yet to learn about SARS-CoV-2. For instance, anecdotal reports suggest that this coronavirus, like other viruses, seems to offer some protection against reinfection, but we still don't know how long that protection lasts, nor do we know why certain people get really sick and others don't. Read more here on where our knowledge on Covid-19 currently stands — and where the gaps are.