Wells: So I get up, I go to my coffee shop. Am I wearing a mask?
Yong: Let’s be very clear about the masks. First, health-care workers need them above everyone else. The supply for health-care workers first needs to be stabilized, and I think there’s still a question mark about how long that will take.
Wells: It could be longer than July?
Yong: I really don’t think we should be overly optimistic about what supply chains are going to be capable of doing. People have this sort of innate sense that this being America, a powerful and rich nation, having identified the problem, we can fix it. But one of the experts I spoke to told me that this isn'’t a problem about dollars and cents; this is a problem of physics. How much of a thing can you make and where can you get it to? Come July, we might have gotten past the first wave of the pandemic, but other countries might be getting into their first peak or getting into a second. The demand on these resources is already stretched.
The other thing is that the masks are not for protecting you; the masks are for protecting other people from you. Everything depends on whether people can get used to that idea and see the masks as this sort of communal good. If they don’t and if they still think of the masks as a way of protecting themselves, they’re probably also going to be less likely to wear masks.
Wells: Got it. So I’m at the coffee shop. I’m probably wearing a mask. Do I know if I have had the coronavirus yet?
Yong: There has been lots of talk of immunity testing—looking for antibodies that people would typically build up in response to an infection to see whether you have been previously infected and therefore might be immune and able to just go about your business freely without worrying about either getting infected or infecting other people. There are many problems with this idea. First, we don’t know if people with antibodies who test positive are capable of transmitting the virus to other people.
Wells: You could be immune and contagious?
Yong: That’s a possibility. Even if you have antibodies against the new coronavirus, we don’t know whether those antibodies do you any good or not. Antibodies can stick to different parts of the virus, and vary greatly in their effectiveness depending on where they stick. So do you have the right kind of antibodies? We don’t know, and the tests that people are talking about can’t tell you.
Let’s say you have the right antibodies. Do you have enough? Even for diseases we’ve studied for more than a century, it’s still not clear what level of antibody in your body would provide sufficient protection. But let’s say we work all of those things out. It would take a mammoth and probably unlikely effort by your birthday. But let’s assume that miracles happen and we know those things.
The big problem that remains is called the base-rate problem, which is that even tests that seem accurate can be wildly misleading if they’re testing for something that is still rare in the general population. By July, only a minority of Americans will have experienced this virus. Even if your antibody test has a small false-positive rate—a small chance of telling someone that they have antibodies when they actually don’t—the fact that so few people are infected means that the number of false positives is going to massively outweigh the number of true positives.