They arent sure if antibodies are warrant immunity.
Immunity from COVID-19 antibodies not certain, HIV co-discoverer cautions
NBC News: What do you think the need is right now for an antibody test?
Gallo: The No. 1 reason for me is to know the extent of the epidemic. You're able to follow the spread of the virus to know the reality of what is going on.
Some people will say the tests can do more. They'll say, 'well, the antibody test also means you can go back to work.' That may be true, but we can’t tell if the antibodies are protective. There are some suggestions that when you have antibodies, you're associated with clearing the virus when the antibody titers are good. [A titer is a measurement of antibody levels in a person's blood.]
But that's not always the case. Sometimes the antibodies are positive and the person is still very infectious. So, you have to remember that.
I'd like to say there are antibodies and there are antibodies and there are antibodies. Some are nothing at all. Some are protective indicators. And sometimes, though not so commonly, they can make matters worse.
For example,
dengue fever — if you get infected and have antibodies and then get infected again, you do worse. Another one is in babies, the
respiratory syncytial virus. They can have antibodies that make things worse.
NBC News: How confident are we that if we do have these antibodies and we're identifying the correct ones, that we've now
become immune, that we can't get sick again?
Gallo: We've been hearing that at
those press conferences, but I don't agree with it. I think that you have no idea that you're going to be protected, because you don’t have the data. There are variations. Take HIV for example — if you have certain antibodies and a lot of antibodies against HIV, you're not protected.
It takes more than that. It takes very, very specific kinds of antibodies at a high enough titer count
On the other hand, a positive antibody could mean you're protected. But it could mean what I mentioned with dengue. I don't think it is. But imagine what it would mean that you'd be worse off.
So you understand that you're hearing statements that are simplistic a lot of times. I don't understand why they just can't say, it's likely that will be true, but we cannot say that with any absolute certainty.