Coronavirus News (203)

तराईमा अब लकडाउन गरे पनि नियन्त्रण हुँदैन, यही तालले काठमाडौंमा पनि ‘डिजास्टर’ हुन्छ : डा. अनुप बास्तोला

 New Evidence Suggests Young Children Spread Covid-19 More Efficiently Than Adults

A Second Coronavirus Death Surge Is Coming There was always a logical explanation for why cases rose through the end of June while deaths did not.

A Vaccine Reality Check So much hope is riding on a breakthrough, but a vaccine is only the beginning of the end.  .......  Nearly five months into the pandemic, all hopes of extinguishing COVID-19 are riding on a still-hypothetical vaccine. And so a refrain has caught on: We might have to stay home—until we have a vaccine. Close schools—until we have a vaccine. Wear masks—but only until we have a vaccine. During these months of misery, this mantra has offered a small glimmer of hope. Normal life is on the other side, and we just have to wait—until we have a vaccine. ............  the media’s blow-by-blow coverage of vaccine trials. Each week brings news of “early success,” “promising initial results,” and stocks rising because of “vaccine optimism.” But a COVID-19 vaccine is unlikely to meet all of these high expectations. The vaccine probably won’t make the disease disappear. It certainly will not immediately return life to normal. ........................  Biologically, a vaccine against the COVID-19 virus is unlikely to offer complete protection. Logistically, manufacturers will have to make hundreds of millions of doses while relying, perhaps, on technology never before used in vaccines and competing for basic supplies such as glass vials. Then the federal government will have to allocate doses, perhaps through a patchwork of state and local health departments with no existing infrastructure for vaccinating adults at scale. ...........  20 percent of Americans already say they will refuse to get a COVID-19 vaccine, and with another 31 percent unsure, reaching herd immunity could be that much more difficult. ............   Scientists have gone from discovery of the virus to more than 165 candidate vaccines in record time, with 27 vaccines already in human trials. Human trials consist of at least three phases: Phase 1 for safety, Phase 2 for efficacy and dosing, and Phase 3 for efficacy in a huge group of tens of thousands of people. At least six COVID-19 vaccines are in or about to enter Phase 3 trials, which will take several more months. ............  Without the measures that have beat back the virus in much of Europe and Asia, there will continue to be more outbreaks, more school closings, more loneliness, more deaths ahead. A vaccine, when it is available, will mark only the beginning of a long, slow ramp down. And how long that ramp down takes will depend on the efficacy of a vaccine, the success in delivering hundreds of millions of doses, and the willingness of people to get it at all. It is awful to contemplate the suffering still ahead. ............  “Nobody wants to hear it’s not just right around the corner.” ............  “The primary benefit of vaccination will be to prevent severe disease,” says Subbarao. A COVID-19 vaccine is unlikely to achieve what scientists call “sterilizing immunity,” which prevents disease altogether. ...............   An initial vaccine might limit COVID-19’s severity without entirely stopping its spread. Think flu shot, rather than polio vaccine. ............   Moderna, an American company, is conducting its Phase 3 trial in the U.S. A group based at the University of Oxford, which is collaborating with the U.K.-headquartered biotech company AstraZeneca, is running trials in Britain, Brazil, and South Africa—the latter two countries chosen specifically because of their high numbers of COVID-19 cases. ...................  The leading COVID-19 vaccine candidates rely on technology that’s never been used before in approved vaccines. Moderna’s vaccine, for example, is a piece of RNA that encodes a coronavirus protein. Oxford and AstraZeneca’s vaccine attaches a coronavirus protein to a chimpanzee adenovirus. Neither has been manufactured before on the necessary scale. ..........  Right now, Operation Warp Speed is also awarding contracts to make the millions of syringes and glass vials needed to package a COVID-19 vaccine. Without careful planning on these fronts, the U.S. could run into a demoralizing scenario where vaccines are available, but there is no way to physically get them to people. .............   When vaccines are approved, 300 million doses will not be available all at once, and a system is needed to distribute limited supplies to the public. This is exactly the sort of challenge that the U.S. government has proved unprepared for in this pandemic. ............  Some of the leading COVID-19 vaccine candidates could also pose new logistical challenges, if they require storage at temperatures as low as –80 degrees Celsius or multiple doses to be effective. In fact, a COVID-19 vaccine is quite likely to require two doses; the first primes the immune system, allowing the second to induce a stronger immune response. Officials would have to balance giving one dose to as many people as possible with giving a second dose to those who already had one. “That was a complication we didn’t face in 2009, and we were so grateful” ................  the Department of Defense may also get involved in vaccine distribution. “We continue to ask CDC these many, many questions. And they don’t know” ..........   If the pandemic so far is any indication, a vaccination program is likely to take place against a backdrop of partisanship and misinformation. Already, conspiracy theories are spreading about a COVID-19 vaccine, some of them downright outlandish. ...............   even a vaccine might not get the country to herd immunity if too many people refuse it. ............  “I think the question that is easy to answer is, ‘Is this virus going to go away?’ And the answer to that is, ‘No,’” says Karron, the vaccine expert at Johns Hopkins. The virus is already too widespread. A vaccine could still mitigate severe cases; it could make COVID-19 easier to live with. The virus is likely here to stay, but eventually, the pandemic will end.