郑州郑州市近视眼激光手术(郑州激光近视手术洛阳) (今日更新中)

The first experimental COVID-19 vaccine in the U.S. is on track to begin a huge study next month to prove if it really can fend off the coronavirus, while hard-hit Brazil is testing a different shot from China.Where to do crucial, late-stage testing and how many volunteers are needed to roll up their sleeves are big worries for health officials as the virus spread starts tapering off in parts of the world.Moderna Inc. said Thursday the vaccine it is developing with the National Institutes of Health will be tested in 30,000 people in the U.S. Some will get the real shot and some a dummy shot, as scientists carefully compare which group winds up with the most infections.With far fewer COVID-19 cases in China, Sinovac Biotech turned to Brazil, the epicenter of Latin America’s outbreak, for at least part of its final testing. The government of S?o Paulo announced Thursday that Sinovac will ship enough of its experimental vaccine to test in 9,000 Brazilians starting next month.If it works, “with this vaccine we will be able to immunize millions of Brazilians,” said S?o Paulo′s Gov. Joao Doria.Worldwide, about a dozen COVID-19 potential vaccines are in early stages of testing. The NIH expects to help several additional shots move into those final, large-scale studies this summer, including one made by Oxford University that’s also being tested in a few thousand volunteers in Brazil.There’s no guarantee any of the experimental shots will pan out.But if all goes well, “there will be potential to get answers” on which vaccines work by the end of the year, Dr. John Mascola, who directs NIH’s vaccine research center, told a meeting of the National Academy of Medicine on Wednesday.Vaccines train the body to recognize a virus and fight back, and specialists say it’s vital to test shots made in different ways — to increase the odds that at least one kind will work.Sinovac’s vaccine is made by growing the coronavirus in a lab and then killing it. So-called “whole inactivated” vaccines are tried-and-true, used for decades to make shots against polio, flu and other diseases — giving the body a sneak peek at the germ itself — but growing the virus is difficult and requires lab precautions.The vaccine made by the NIH and Moderna contains no actual virus. Those shots contain the genetic code for the aptly named “spike” protein that coats the surface of the coronavirus. The body’s cells use that code to make some harmless spike protein that the immune system reacts to, ready if it later encounters the real thing. The so-called mRNA vaccine is easier to make, but it’s a new and unproven technology.Neither company has yet published results of how their shots fared in smaller, earlier-stage studies, designed to check for serious side effects and how well people’s immune systems respond to different doses.Even before proof that any potential vaccine will work, companies and governments are beginning to stockpile millions of doses so they can be ready to start vaccinating as soon as answers arrive.In the U.S., a program called “Operation Warp Speed” aims to have 300 million doses on hand by January. Under Brazil’s agreement with Sinovac, the Instituto Butantan will learn to produce the Chinese shot.___AP journalist Marcelo Silva de Sousa contributed to this report.___The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content. 3499

The daughter of a hiker who was missing in Zion National Park for nearly two weeks has told CNN that her mother injured her head and became disoriented during the hike.Holly Courtier, 38, was found Sunday after having not been seen since she was dropped off by shuttle on Oct. 6. Courtier's daughter, Kailey Chambers, pleaded with volunteers to help find her mother during the disappearance, saying Courtier was an experienced hiker who would not have gone missing as she did without a reason.In text messages with the cable network, Chambers gave an explanation for what happened to her mother during the two weeks she was missing."She injured her head on a tree," Chambers texted. "She was very disoriented as a result and thankfully ended up near a water source -- a river bed. She thought her best chance of survival was to stay next to a water source."In the texts, Chambers says her mother went without food the entire time she was missing."She was too weak and disoriented (to seek help)," she said. "She was unable to take more than a step or two without collapsing. This prevented her from being able to seek out help. She told me she was so dehydrated she couldn't open her mouth."Courtier was found in the park Sunday after officials received a tip from a credible source. 1291

The cold open of "Saturday Night Live" usually belongs to politics, but on Saturday night it belonged to moms.The mothers of cast members from the NBC variety show took over the beginning of Saturday's episode with many taking jabs at the show's political jokes.Kenan Thompson asked his mother if she liked the show and she responded, "I do, except for all the political stuff. We get it!"Mikey Day introduced his mother and reminded her of the time he was in a production of "The Crucible" in high school."You know, 'The Crucible' is a lot like that witch hunt against President Trump," Day's mother said before Day quickly ushered her off.The mother of the newcomer Luke Null asked, "Why doesn't 'SNL' talk about 'Crooked Hillary'?""Mom, I'm so new here," he said. "Please don't do this to me."As for Chris Redd's mother, she wondered why everyone is focused on Trump rather than "focusing on Jesus.""Okay, well, Jesus isn't president," Redd said."And that's the problem," his mother said back.And "Weekend Update" host Colin Jost asked his mom if she likes the political stuff on the show."I think Alec Baldwin does a great Trump impression," she said. "But why does it have to be so mean? Who writes that stuff?"Jost, who is also one of the show's head writers, hesitated and responded saying he didn't know blaming his "Weekend Update" co-host, Michael Che, who is also a head writer, for the jokes. 1412

The day after President Donald Trump signed a historic peace agreement with world leaders and attended a town hall event in Philadelphia, there are reports White House staff members may have tested positive for COVID-19.During his White House briefing on Wednesday, President Donald Trump confirmed that one person, who is part of the WH staff, tested positive for the coronavirus.A reporter for Globo, a Brazillian media outlet, who is part of the White House press corps tweeted Wednesday morning that she learned of the positive cases when the corps own testing was late. 582

The Cruise Lines International Association announced Tuesday that any cruise ship worldwide carrying more than 250 people must test everyone, passengers and crew members, for COVID-19 before embarking.They must also test negative for the virus if they are to board the ship, CLIA said in a press statement posted to their social media account."CLIA ocean-going cruise line members have agreed to conduct 100% testing of passengers and crew before embarkation - a travel industry first," CLIA tweeted. 508

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