Transcript for The latest on COVID-19 antibodies and immunity
we are tracking, diagnosed coronavirus cases worldwide at more than 16.4 million with now more than 148,000 Americans killed in the crisis as more than 1.3 million recover here. And we have some good news for you today because fresh off of a few days off we have ABC chief medical correspondent Dr. Jen Ashton with us. Good to be back, Amy. Nice to have you back in the saddle now. Obviously we've had some big news today about two major vaccine developers entering phase three of clinical trials. That is certainly some good news as well but there's still a lot of scientists that are learning about immunity, what we're trying to figure out about what the data has shown that antibody levels wane after about three months. Right. So what's the latest on covid-19 and immunity? Here's what's been confusing, Amy. We hear these news bulletins and they tend to ping-pong back and forth between good news about immunity in terms of a vaccine response, maybe not so good news in terms of how long those antibody levels last. So here it is right down the middle starting with what we know at this point about covid-19 and immunity. First of all, basic premise of science is that when we are exposed to some kind of pathogen, antibodies are produced and this is after a natural infection or after vaccine exposure. The other thing is that there are two types of cells that really dictate and drive our immune response. There are B cells and T cells. T cells also known as cellular immunity. People may be hearing about that more down the road in terms of covid-19. Now, some of these antibodies are general and nonspecific. Some are very specific, and those are what we call neutralizing antibodies. They protect us or block us from that infection down the road. Early data, promising, shows that volunteers who have been injected with early vaccine doses do develop neutralizing antibodies higher than levels or as high as people who have been naturally infected, so that's some good news about our immunity. Speaking about these different types of antibodies, it was recently discovered that some of the commercially available antibody tests may not even be looking for the best antibodies, so what does that say about how it could affect the risks of reinfection, even the vaccine success? We have to connect the dots on this, Amy, because people are getting these tests and trying to utilize them to try and drive our behavior and decision-making. Some of these tests may actually be looking for a difficult protein on the virus, not on the surface of that spike protein that people know based on its appearance. The antibody levels of one type may not be reflective of immunity, so again, we need more information on this and we're learning about it in real time. And then exposure to coronavirus either via the vaccine or naturally could produce higher or different levels of antibodies. This is also a basic premise in medicine and we're learning based on some published data, mild or asymptomatic natural infection of covid-19 may not be yielding the same levels of antibodies as people who were more severely ill. So again, this is not a one size fits all or black or white issue. All right, thank you, Jen.
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