[ti:COVID-19 Vaccine Trial Suspended after 'Unexplained Illness'] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]Drug-maker AstraZeneca has temporarily suspended its COVID-19 vaccine tests [00:07.16]after an "unexplained illness" in a person who took the treatment. [00:13.08]In a statement released Tuesday, the company said, "This is a routine action [00:19.00]which has to happen whenever there is a potentially unexplained illness in one of the trials." [00:26.92]The announcement came shortly after the drug-maker joined eight other companies [00:32.76]in a promise to follow safety measures in vaccine development. [00:38.88]AstraZeneca's vaccine candidate is being developed with the University of Oxford. [00:46.28]It has been described by the World Health Organization (WHO) [00:50.00]as probably the world's leading vaccine candidate to fight COVID-19. [00:58.04]On Wednesday, Dr. Soumya Swaminathan, the WHO's chief scientist, [01:04.20]said "for drugs and vaccines which are given to people, [01:08.60]you have to test their safety, first and foremost." [01:14.04]Late last month, AstraZeneca began looking for 30,000 volunteers [01:19.92]in the United States for its large Phase 3 trials of the vaccine. [01:26.64]It also is testing the vaccine in thousands of people in Britain, [01:31.24]and in smaller studies in Brazil and South Africa. [01:37.48]Two other COVID-19 vaccine candidates with large Phase 3 trials in the U.S. [01:44.60]include one made by Moderna and the other by Pfizer and Germany's BioNTech. [01:52.60]During Phase 3 trials, researchers look for any signs of possible side effects. [02:00.28]The trials also judge effectiveness by studying who gets sick [02:04.92]and who does not among patients taking part in them. [02:10.04]People in one group get a real shot and people in another group [02:14.56]receive an inactive shot as part of the test. [02:19.80]AstraZeneca pointed out that "In large clinical trials, [02:24.24]illnesses will happen by chance and must be independently reviewed." [02:31.20]And the company said it is working to limit possible "impact on the trial timeline." [02:38.72]Dr. Anthony Fauci is the top infectious disease expert in the U.S. [02:45.24]He told CBS News on Wednesday that it is "not uncommon" [02:50.40]for vaccine makers to suspend trials. [02:55.04]He added, "That's the reason why you have various phases of trials, [03:00.32]to determine if in fact these candidates are safe." [03:05.96]Dr. Ashish Jha, a researcher with Brown University, said on Twitter, [03:12.08]"We have no idea whether this is a big deal or not. Science is hard. [03:17.72]This is why we have to let the trials play out." [03:22.40]He added that he was hopeful: "I remain optimistic we will have a vaccine [03:28.68]found to be safe and effective in upcoming months." [03:34.24]Britain's medical agency said it is reviewing the information [03:38.68]to decide whether trials can restart as quickly as possible. [03:44.44]The U.S. National Institutes of Health, which is providing financial support [03:49.56]for AstraZeneca's trials, did not comment. [03:54.04]The suspension of the trials followed reports that the United States [03:58.16]was aiming for quick approval possibly before the November 3 presidential election. [04:06.08]AstraZeneca has already agreed to supply nearly [04:09.96]three billion doses to governments around the world. [04:15.52]The New York Times reported that a volunteer in the Britain trial [04:19.80]was found to have transverse myelitis. [04:24.40]It is an inflammatory problem that affects the spinal cord [04:28.88]and is often started by viral infections. [04:33.56]The information came from an unidentified person with knowledge of the situation. [04:40.64]AstraZeneca did not comment. [04:44.16]The Reuters news agency also reported that the illness happened in the British trial. [04:50.64]The large trial began in May with more than 12,000 volunteers [04:55.84]who were between five and at least 70 years of age. [05:01.76]Stat News was the first news organization [05:05.16]to report AstraZeneca's decision to suspend the trials. [05:11.08]It said the decision has affected trials being carried out by other vaccine makers, [05:17.20]which are now looking for signs of similar reactions. [05:22.76]I'm Jonathan Evans. 更多听力请访问51VOA.COM