 There are actually a few different variants that are emerging that you've probably been hearing about recently. Two of the most common ones that people are talking about and most concerned about are something they call the D117 versus B1351. They emerged in the UK and they emerged in South Africa and really they were noticed in December, but they were circulating before that, so it seems like they're both circulating around October at least. Both of these, the data suggests that it's more transmissible. Most of the data that's available is for the UK variant in particular. And for that one, it's still not clear exactly how much more transmissible it is, but current estimates are that it's somewhere between 30 percent more transmissible and 80 percent more transmissible than the original strains that were out there. The first thing that I should say is that these variants, there's no evidence that there's increased disease severity as a result of these variants, so it doesn't seem like it is now more harmful given that you're already infected. But the concern is that now if they are more transmissible and it looks like they are more transmissible, what that means is more people are going to get infected and so more total people are going to get sick. And really, as far as what that means, that means that you sort of get hit twice with it. The first one is that there's going to be more people around who are infectious, so it's more likely that you're going to get infected from them. And then even if there was only one infectious person, that person is more infectious. With that said, the basics of how we're supposed to live our life and how we're supposed to control this are essentially unchanged, right? The mitigation measures that we have in place, things like social distancing, wearing a mask, avoiding indoor shared spaces, reducing any unnecessary risks, those things are still the best measures that we have to try to control this until we have access as individuals to get vaccines and protect ourselves in other ways. So if we look at smallpox and smallpox vaccine, we never saw resistance evolve to it. Measles, polio, the majority of vaccines that we have, we never have to update them or anything like that. But there are vaccines where we do have to update them where resistance evolves. And so part of the concern about these new variants is that there might be evolution of resistance to the vaccines that are currently being developed. And the reason people are concerned about that is that a lot of the mutations in these new variants are at the sites where the vaccine is providing protection, something called the spike protein. And so we're seeing changes in the spike protein and the vaccine is targeting the spike protein. Now, just because we're seeing changes doesn't mean that that's going to undermine the vaccine. Vaccines tend to be robust against evolutionary change. And so my hope and my expectation is that the vaccines will still be robust, but it's worrying and we have to keep an eye on it to study it more.