字幕列表 影片播放 列印英文字幕 This episode is sponsored by Awesome Socks Club, a sock subscription for charity! Click the link in the description and sign up between now and December 11th to get a new pair of fun socks each month in 2021. Also, our usual COVID disclaimer: This episode was filmed on December 1st! For our most up to date information about the COVID-19 pandemic, check out the playlist linked in the description. [♪ INTRO] We've been getting lots of vaccine news for the last few weeks, including that multiple drug developers are taking the next steps towards rolling out vaccines to the public. Like, on November 20th here in the US, the pharmaceutical company Pfizer applied for an Emergency Use Authorization for the COVID-19 vaccine developed by BioNTech. And Moderna filed the application for theirs ten days later — on Monday. That's a big step! But it also doesn't mean we have multiple vaccines about to be rolled out. It'll likely still be months, maybe even more than a year, before you can stroll down to your doctor's office or local pharmacy and get one of these vaccines. These may not even end up being the vaccines we use for this disease! Still, there is some really awesome science to talk about here, because these vaccines are a totally new thing! In the last few months, you've probably heard people, including us, talk about how vaccines take time to develop. The design process and lab tests usually take months, sometimes even years. But things are different during a serious emergency, like a global pandemic. Investors inject lots of cash into drug development to speed along the lab work and clinical trials. Still, there's a lengthy formal approval process, overseen here in the US by the Food and Drug Administration. Except! There can be a way to temporarily bypass that. If someone above the FDA declares that there's a special kind of medical emergency — one that goes beyond a normal “public health emergency” — then, the FDA may consider applications for Emergency Use Authorizations or EUAs. These grant temporary, limited approval for things that might help tackle the emergency. Essentially, the FDA does a complex and careful risk-reward calculation. As long as the treatment, vaccine, or test shows that it might be effective for the declared emergency — and there are no good alternatives — then it can be considered for an EUA. And that's what's happened with COVID-19 and these vaccines. To try to get an EUA, the evidence supporting these vaccines will first be reviewed by a panel of outside scientists and public health experts, followed by the FDA. For the vaccine developed by BioNtech, that FDA review is scheduled for December 10. Moderna's will follow a week later. That said, there's nothing that says the FDA has to grant these authorizations. And even if they do, the companies have already made it clear that producing enough doses to treat everyone in the US, let alone other countries, is going to take quite a bit of time. Any doses that become available in the next few months will likely be first prioritized for medical personnel and other high-risk groups around the world. That means we don't know exactly when everyone will be able to get a vaccine, but it's not going to be soon. Also, there's a chance that there'll be a snag along the way. By design, EUAs last until the emergency is over, the drug is formally approved, or new evidence emerges that calls into question how useful the drug is. That's what happened with the drug hydroxychloroquine: it got an EUA for treating COVID, and then the EUA was pulled after studies failed to find it actually helped. And these vaccines haven't been tested in a lot of the people we'd want to give a COVID vaccine to, like kids or people with common chronic health conditions. Which is why experts are being cautious about firing their confetti cannons just yet. There is something kind of cool about these two vaccines in particular, though: they're unlike any vaccines you've received to date. They're what we call mRNA vaccines. All vaccines work by training your body to recognize a pathogen so it can disable it and flag it for destruction. Some vaccines do this with a dead or weakened version of the germ, like your annual flu shot. Others, like the Hep B vaccine, just contain the specific part of the germ your immune system needs to know to take it out. And that's kind of the path these new vaccines took — they teach your cells to spot a part of this coronavirus called the spike protein. But here's the big difference: they don't actually contain that protein — they only have genetic instructions for it, in the form of messenger RNA, or mRNA for short. That's the same kind of molecule our cells normally use to build proteins from. But these ones are carefully designed and manufactured. This manufactured mRNA gets packed into little fat-based nanoparticles that deliver it into our cells. Once that happens, our cells build the spike proteins that the immune system ends up learning to spot. So these vaccines take advantage of the fact that our cells have all these little protein factories just waiting for mRNA instructions to tell them what to make! The key thing to note here is that making this kind of vaccine doesn't require an actual sample of the live virus — just its genome sequence, which Chinese researchers made available super quickly. That let the developers seriously cut down on production time. When the genetic blueprint of the new coronavirus became available in January, researchers were able to design an mRNA that codes for spike protein in a matter of days, and make testable versions of the vaccine in about a month. That might sound futuristic because… it kind of is! Different research groups have been studying mRNA vaccines for decades now, so they didn't just pop up out of nowhere. A few similar vaccines have been approved for veterinary use. But, if granted EUAs, these two would be the first mRNA vaccines to be given to people outside of clinical trials. And if they do end up working wonderfully, they could usher in a whole new era of vaccine design. That is a big if, though. So far, the vaccines seem to be doing well. According to the companies, there are more side effects than usual with a vaccine, including things like fevers and sometimes-intense headaches. But they appear to be effective in keeping trial participants from getting sick with COVID-19. And that gives us hope that they'll help us slow this virus down and save people's lives. But it's also important to remember that EUAs don't mean something is proven. While their lightning-quick development helped these mRNA vaccines submit US EUA applications faster than other vaccine candidates, they may not end up being our final solution. And even if they do emerge as the COVID vaccines, the pandemic isn't over by any stretch. So we all need to keep doing what we can to keep everyone safe. Thanks for watching this episode of SciShow News! I do have a bit of unambiguously good news to share —at least, if you're the kind of person who likes awesome socks. Hank and John Green have started a new charity project called the Awesome Socks Club! It's super simple: if you sign up, you get a fancy new pair of socks each month of 2021. Each pair was created by a different designer, and they're all going to be super fun. Like, one of them is covered in smiling bananas! Because everyone needs happy bananas on their feet. Also, 100% of the after-tax profit will go to decrease maternal and child mortality in Sierra Leone, which is one of the most dangerous places to be pregnant in the world. But here's the catch: you only have one week left to subscribe! You have to sign up by December 11 —otherwise, no socks for you. Or at least not these fun socks. So if you're interested, click the link in the description! [♪ OUTRO]
B1 中級 美國腔 关于COVID疫苗和紧急使用授权的真相(The Truth About COVID Vaccines and Emergency Use Authorizations) 18 1 joey joey 發佈於 2021 年 05 月 24 日 更多分享 分享 收藏 回報 影片單字