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- Hi, I'm Julie from the Exploratorium. Welcome to Viral Questions. Series of videos where we answer your questions about COVID and vaccines. Today's question is about whether current vaccines work against the new coronavirus variants? To answer that we need to think about what a new variant is, and also get into a little more detail about what vaccines do. Let's start with variants. Every time a virus multiplies there're chances for mutations. That's actually true of us too. Every time our cells divide, there's a chance that some change or mutation takes place. Due to a mistake made when copying our genetic information. Now viruses tend to make more mistakes than humans. And these mistakes aren't always a big deal. Most of the time, they don't make any difference. Sometimes though, they're detrimental to the virus. And sometimes they actually make the virus better at its job of making more viruses. Mutations can happen anywhere, but we're gonna focus on mutations to the main virus protein we've been discussing. That's the spike protein on the surface of coronavirus. Remember the spike protein is how the virus attaches to and enters a human cell. Today we're gonna zoom in and look at it in more detail. Now I haven't representing it as a simple cartoon, but scientists have a good idea of what it actually looks like in three dimensions. You'll notice that rather than being a smooth cartoon, it's actually quite lumpy. A protein's three-dimensional structure is how it interacts with other proteins. This top part of the spike protein is where it binds to a cell, by attaching to a protein on your cell called a receptor. You can think of it like two jigsaw puzzle pieces fitting together, but in three dimensions. We'll switch back to a cartoon to make this easier to visualize. Now that we know that the spike protein actually has quite a bit of three-dimensional structure, I'll represent those with these shape cutouts. These structures are how spike proteins interact with other molecules like your cell receptors. Any changes to the part of the spike protein that binds through receptor, might disrupt how well it attaches to your cell. For example, a change might make the puzzle piece not fit anymore, making it a bad mutation for the virus because it can't get in. Or it could shift to make an even tighter fit with your cell. Like when you think you have two puzzle pieces that sort of match, but then you find a piece that has an even better fit. This better fit mutation has actually already happened a number of times with SARS-CoV-2. And it's thought that this mutation is part of what's causing some of the variants to be more infectious. Their fit with ourselves seems to be a little tighter, allowing more viruses to get in. Coronavirus variants have a number of different mutations. Some of which change how the virus behaves like the one I just mentioned, and some of which don't. So what does that mean for vaccines? Remember that the ultimate goal a vaccine is to train your immune cells to create antibodies against the coronavirus. Should you then be exposed to the virus, The antibodies will mark them for destruction. In an earlier video, I mentioned that the spike protein is an antigen. Antigens get their name from being antibody generators. And if we zoom in again, we can see that different sections of the spike protein actually generate different antibodies. So one antibodies binding site might recognize the part that attaches to your cell, and there might be other ones that identify other parts of the spike protein. When you get vaccinated, your body produces a multitude of antibodies. And you have cells that keep each of these different shapes in their memories. As a spike protein evolves and changes, some of your antibodies might not recognize it anymore. But the good news is that the other ones should still work. The bad news is that there could be a point where enough of the virus evolves that the current vaccines won't generate enough antibodies to fight the new variant. Studies are ongoing, but current vaccine seems to be effective against the new variants we've identified. Though possibly less so than they are against the original one. You may have heard experts say that we're in a race between vaccination and these new variants. What we're really trying to do is reduce the overall number of viruses to limit the chance that a new variant will evolve to be completely resistant to our current vaccines. Plus fewer people will get sick. Even with lower numbers of viruses, could a variant still evolve that escapes existing vaccines? Unfortunately, yes. That's how probability works. So scientists are looking into possible booster shots that will train our immune systems on new spike protein variants as well. Fortunately, vaccines provide us with a tool that can help us navigate future changes. But they'll only work if enough people get vaccinated. Thank you so much for watching and please continue to ask your questions in the comments. We'll see you next time.