TSD: Would you describe this mechanism as populations achieving herd immunity?
ML: You don’t actually have to infect everybody, depending on how fast the virus grows. Some people say 80% [of the population needs to develop antibodies], some people say 60%. I personally think it’s less than 30%. And some people are saying we’re never going to get herd immunity. I don’t think so.
TSD: Why not?
ML: There have been maybe five or six situations where there was massive infection, including on the Diamond Princess cruise ship or provinces in Italy. You will find that the final death count is something like a tenth of a percent of the population. You could say that each of these places stopped because they had wonderful social distancing, or we can simply say they stopped because there was no one left to infect. We will know in a few weeks the answer to this question because of what happens in Sweden.
TSD: Sweden?
ML: If Sweden stops at about 5,000 or 6,000 deaths, we will know that they’ve reached herd immunity, and we didn’t need to do any kind of lockdown. My own feeling is that it will probably stop because of herd immunity. COVID is serious, it’s at least a serious flu. But it’s not going to destroy humanity as people thought.