石家庄膝关节及韧带附矢状剖面模型(北京人体男女性头颈躯干横断断层解剖模型) (今日更新中)

The Food and Drug Administration released updated safety standards Tuesday for makers of COVID-19 vaccines despite efforts by the White House to block them, clearing the way for requirements that are widely expected to prevent the introduction of a vaccine before Election Day.In the new guidelines posted on its website, the FDA said vaccine makers should follow trial participants for at least two months to rule out any major side effects before seeking emergency approval. That standard had been a sticking point between the FDA and White House officials, who said it could unreasonably delay the availability of COVID-19 vaccines.President Donald Trump has repeatedly insisted a vaccine could be authorized before Nov. 3, even though top government scientists working on the effort have said that timeline is very unlikely. On Monday Trump said vaccines are coming “momentarily,” in a video recorded after he returned to the White House.Former FDA officials have warned that public perception that a vaccine was being rushed out for political reasons could derail efforts to vaccinate millions of Americans.A senior administration official confirmed Monday that the White House had blocked FDA’s plans to formally publish the safety guidelines based on the two-month data requirement, arguing there was “no clinical or medical reason” for it.But on Tuesday, the FDA posted the guidance on its website, making clear that regulators plan to impose the safety standards for any vaccine seeking an expedited path to market.FDA Commissioner Stephen Hahn said in a statement that he hoped the guidelines would help “the public understand our science-based decision-making process that assures vaccine quality, safety and efficacy.”The requirements are aimed at companies seeking rapid approval through the FDA’s emergency authorization pathway. That accelerated process, reserved for health emergencies, allows medical products onto the market based on a lower bar than traditional FDA approval. But FDA has made clear only vaccines that are shown to be safe and effective will be authorized for coronavirus.Former FDA acting commissioner Dr. Stephen Ostroff said the requirements seem reasonable given the agency is in largely “uncharted territory” in terms of considering emergency use of a vaccine. The agency has only previously cleared one vaccine through the method — a decades-old shot that was authorized to prevent anthrax poisoning in 2005.“There really is no margin for error here,” Ostroff said. “Even when you’re talking about limited use of a vaccine there has to be some level of assurance that there isn’t a risk here that would far outweigh the benefit.”Dr. Peter Marks, the head of FDA’s vaccine division, said Tuesday that the two-month follow-up requirement was chosen to be “something reasonably aggressive, but not too conservative — right in the middle.” He spoke at a symposium organized by Johns Hopkins University.Initial doses of vaccines for emergency use would likely be reserved for medical workers and people with health conditions that make them particularly vulnerable to coronavirus. Full FDA approval for the general population will require significantly more data and is not expected until mid-2021.The White House attempt to block the guidance followed a string of instances in which the Trump administration has undercut its own medical experts working to combat the pandemic. FDA’s Hahn has been attempting to shore up public confidence in the vaccine review process for weeks, vowing that career scientists, not politicians, will decide if the shots are safe and effective.Pfizer CEO Albert Bourla has stoked excitement by saying that he expects data on whether the company’s candidate works to be ready in late October. But a number of variables would still have to align for the company to submit, and the FDA to review and greenlight, a vaccine application before Nov. 3. Pfizer’s competitors Moderna, AstraZeneca and Johnson & Johnson are working on longer research timelines.Vaccine development typically takes years, but the U.S. government has invested billions in efforts to accelerate the process and help multiple drugmakers prepare multiple candidates. All the doses will be purchased by the federal government for use vaccinating the U.S. population.Beyond exposing the rift between the White House and FDA, the delay in releasing the guidelines may have had limited practical effect.FDA scientists have been discussing the guidelines publicly for weeks and have made clear that the recommendations have already been shared with each of the vaccine developers.Former FDA Commissioner Scott Gottlieb said Tuesday that drugmakers depend on the FDA’s science-based endorsement to vouch for the safety and effectiveness of their products.“I can’t imagine a circumstance where a sponsor would challenge or seek to undermine the FDA’s role here,” Gottlieb said at the COVID-19 symposium. “This is precisely the moment when we need an objective, neutral arbiter.”Last week, Gottlieb and six other former FDA commissioners blasted the Trump administration for “undermining the credibility” of the agency in a op-ed calling for the release of the then-stalled vaccine guidelines.“Scientists should make decisions based on data, unfettered by political pressure or the intrusions of ideology or vested interests,” the officials wrote.___AP Medical Writer Lauran Neergaard 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. 5644

The current spike in COVID-19 cases is stressing the testing system across the country.As the virus spreads at unprecedented rates, more Americans are seeking COVID-19 tests. But in recent days, companies that make the tests and the supplies needed for them are struggling to keep up with demand."Those companies were operating on an allocation basis, and that just means that basically everything they make is going out the door," said Kelly Wroblewski, the Director of Infectious Disease Programs at the Association of Public Health Laboratories. "There is no reserve, so there's an increased demand in a lab for testing. There's no more reagent to be had, so to meet that demand, that lab has to use a different manufacturer's test."Wroblewski adds that along with issues in getting supplies, officials are also short on human resources — there is only so much lab capacity and only so many trained people to conduct the tests.The American Clinical Laboratory Association says the surge in demand for testing means some labs could reach or exceed their current testing capacities soon — meaning it could take longer for patients to get PCR test results back.Wroblewski says that it can take currently take anywhere from 24 hours to a week to get PCR test results back.With antigen tests, patients can get results back in less than 30 minutes. There is currently enough of a supply for antigen tests, but not all facilities offer them.Both lab groups stress that COVID-19 testing is important, but patients should be strategic."There's been a lot of emphasis put on testing, but testing is only one piece of the puzzle," Wroblewski said. "It gives you some information, and if you're not going to do anything with that information — whether it be targeted closures. whether it be staying home and isolating — we're not going to stop the spread of disease."As far as getting more tests, it's going to take a while. Wroblewski says it could take up to six months or more to increase production capacity significantly. Labs don't expect to see a ramp-up in supplies until early 2021. 2090

The Food and Drug Administration warned pregnant women on Thursday of using some pain and fever medications during the second half of pregnancies.According to the FDA, these nonsteroidal anti-inflammatory drugs can cause rare but serious kidney problems in the unborn baby, which can cause pregnancy-related complications. Nonsteroidal anti-inflammatory drugs include ibuprofen, naproxen, diclofenac, and celecoxib. The FDA added that its warning does not apply to low-dose aspirin.“It is important that women understand the benefits and risks of the medications they may take over the course of their pregnancy,” said Patrizia Cavazzoni, M.D., acting director of FDA’s Center for Drug Evaluation and Research. “To this end, the agency is using its regulatory authority to inform women and their health care providers about the risks if NSAIDs are used after around 20 weeks of pregnancy and beyond.”The FDA says that warnings on prescription nonsteroidal anti-inflammatory drugs already advise of complications past 30 weeks. The newest guidance calls on health care providers to only prescribe the lowest effective dose for the shortest period possible for women 20 to 30 weeks into their pregnancy.More information on the warning can be found here. 1259

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 coronavirus crisis has shown how generous people can be.When the pandemic started, animal advocates from all over North America got together and launched a massive fostering campaign.“I don’t think we ever thought people would be so willing to open up their homes to homeless pets,” said Kristen Hassen-Auerbach with Human Animal Support Services, a group educating others on how to reduce animal euthanasia.The group says the campaign resulted in nearly half of shelter pets going into foster care in April and May.In some places, the wait list was longer than the pets needing placement.“If this moment has taught us anything, it’s that we're all vulnerable. On any day, it could be any one of us that’s facing losing our homes or our pets and this is the time to help each other,” said Hassen-Auerbach.The group is now helping shelters evolve. They want a majority of animals that come into shelters to be in foster homes within hours or days. That frees up money to provide food and medical support to animal owners going through tough times.“We’re finding through early research that dogs in particular are only going a couple of houses to a couple of blocks away from their house. They're really close to home most of the time and many times if someone can just hold an animal for a few hours, they can get it home without the stress of the shelter,” said Hassen-Auerbach.You can find out more about how it works here. 1436

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