What Science Has Learned About the Coronavirus One Year On

Science Talk


It's a really important moment to look back at our very different reality just twelve months ago. In december twenty nineteen the first infections were just emerging inside of china sars. Covy two didn't have a name yet and no one could imagine the global effects that the virus would have on us all but it was also clear that this novel coronavirus lit a fire underneath the seat of science so my question is how far has our scientific understanding about the biology and the behavior of the virus. Come since then yeah. We have learned some really critical things. About how the virus works and also importantly about how our immune system responds to it and how. This virus sars cope chew. Essentially causes our immune system to misfire in cases of severe covid nineteen and miss misfiring really centers on the very early immune responses that. Our body mounts. These are called innate immune responses this innate immunity is a part of our body that really uses sensors that detect pieces of pathogens. Like the co two virus that are not from our own body in once. These factors are sensors detect these viral bits. They sound out an immediate alarm system. That operates through molecules called cytokines and interferons. These are important for activating those later. Immune responses like t cells and antibodies. That we hear about and what we think is that. It's likely that people who sound this innate immune alarm early upon exposure to the virus and induced early in high levels of that interferon alarm system. Go onto pretty rapidly and effectively clear the virus so these might be the individuals with a symptomatic or moderate or mild disease however what scientists have learned. Is that people who go on to develop severe covid. Do so. Probably because in them. The virus causes a misfiring of that. Immune response so like the wrong sets of immune cells may be brought in and they might not deuce that early interferon alarm system. Quick clear strongly in they can't control the viral load. The virus amplifies to really high levels in their body so their body responds to this continued presence of the virus basically by increasing production of factors. That are involved in inflammation. This is an over exuberant inflammation or inflammatory response. And that's what leads to the lung tissue damage which is really a hallmark of code pathology. So what we've discovered. Scientists over the past year is that there are biomarkers. That can give clues about who ultimately goes on to get severe disease. Scientists have also discovered genetic. Differences are mutations that some people have in those innate immune genes that can contribute to poor initial control of the virus. I think that this understanding that there are essentially two phases of covid nineteen disease that initial phase that's dominated by viral amplification in a second phase that in severe cases is dominated by a misfiring of the immune response is really important is important because it ill. At they're two types of therapies. That are probably needed. Depending on the phase of the disease so drugs that charge it the virus directly to stop its replication is would be things like remdesivir that we've heard a lot about in the news or maybe treating with things like recombinant interferon. This is Something that's used to treat other chronic viral infections. Those types of therapies are probably only going to be effective at stopping nets first phase of the disease but are not going to be very effective If they're given during that second phase because it's then it's not the virus but the immune system that's driving illness so conversely drugs that damp a net over exuberant inflammatory response and decks. Methadone is one of those. These might be dangerous. If given during that first phase when you really want a rapid and robust immune response but could be helpful at dampening the damage that's caused by the immune system at later stages one of the key parts of understanding the virus itself. How find it is scientifically really about timing right. Exactly timing is really key to figure out how your body responds very early and later and you know the timing and dose of the virus that you might receive understanding how that timing or the kinetics of infection response are essential and we've made a lot of progress on that over the last year

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