https://www.sciencemag.org/news/2021/01/third-time-s-charm-brazil-scales-back-efficacy-claims-covid-19-vaccine-china Third time’s the charm? Brazil scales back efficacy claims for COVID-19 vaccine from China By Jon Cohen, Sofia MoutinhoJan. 12, 2021 , 5:50 PM Science’s COVID-19 reporting is supported by the Pulitzer Center and the Heising-Simons Foundation. In the third in a series of conflicting announcements about a Chinese-made COVID-19 vaccine candidate, Brazilian researchers reported today that the results of their efficacy trial were less impressive than they claimed last week. When analyzed by stricter criteria than used earlier, the vaccine’s efficacy against all forms of COVID-19, including mild cases, dropped from about 78% to 50%. The vaccine still appeared to give nearly 100% protection against disease severe enough to require hospitalization, although the trial amassed too few of those cases for that result to reach statistical significance. Commenting at the press conference today, microbiologist Natália Pasternak Taschner, president of the Question of Science Institute, a Brazilian nonprofit that aims to support public policy based on scientific evidence, said it was a “clear and clean study” and stressed that she wants the vaccine for herself and her parents. “We do not need to say this is the best vaccine in the world,” said Pasternak, who was not involved with the trial. “We have to say that this is our vaccine and it is a good vaccine to start the process of pandemic control.” The vaccine, made by China’s Sinovac Biotech, contains a chemically inactivated version of SARS-CoV-2, the virus that causes COVID-19. At last week’s press conference that announced the 78% efficacy, Dimas Tadeu Covas, head of the Butantan Institute—a state-owned vaccinemaker in São Paulo that is conducting the study with Sinovac—offered few details. (Information was even sketchier in a press conference last month, when the team claimed only that the efficacy was greater than 50%.) But when pressed by journalists, he responded that this number came from about 220 cases of symptomatic disease. Today, researchers revealed that the 78% figure actually derived from analyzing COVID-19 cases in which people sought assistance for symptoms and tested positive for the virus—31 such cases among placebo recipients in the trial and seven in the vaccinated group. A more detailed analysis that included trial participants who tested positive but had symptoms so mild they did not seek help found 167 cases of COVID-19 in the placebo group and 85 in people who received the vaccine, for an estimated efficacy of 50.34%. Even allowing for statistical uncertainties, that is considerably below the greater than 90% efficacies of three other already authorized COVID-19 vaccines. But Esper Kallas, a study investigator based at the University of São Paulo’s main campus who spoke at the press conference, notes that because definitions of a positive case have varied among trials, “There may not be an accurate comparability between the studies.” In the Brazil trial, the liberal definition of a case “put things to the most difficult test,” said Ricardo Palácios of Butantan, who served as the clinical director of the study. “It is like comparing someone who runs a kilometer on paved ground versus someone running 1 kilometer with obstacles.” World Health Organization guidelines and those of several countries say a COVID-19 vaccine that has 50% efficacy with a lower bound of 30% meets the standards for initial authorization. “It has all the requirements to justify its emergency use,” Covas said. Brazil has one of the most devastating COVID-19 epidemics in the world, and Covas and several other speakers at the press conference said they hoped the Sinovac vaccine—which the Butantan is now producing—would promptly go into widespread use. No vaccine has yet received authorization in Brazil, but regulators are also reviewing efficacy data in one made by AstraZeneca and the University of Oxford. Covas said the reporting of the new data on the Chinese vaccine shows “our complete commitment and transparency in this process.” Earlier, Sinovac had asked Butantan not to release details of the study so the company could more closely analyze the data, leading to assertions that the Brazilian researchers had been muzzled by the company. Sinovac has not responded to repeated requests for comment from Science. Kallas notes the current case analysis only goes through 28 November 2020 and “much more” data are now available. Efficacy trials of the Sinovac COVID-19 vaccine are also underway in Turkey and Indonesia and have presented data that are even more preliminary. Researchers in Turkey reported on 24 December that they found 91.5% efficacy with its first 29 cases, and Indonesia reported 65% efficacy with 25 cases. Indonesia yesterday gave the vaccine emergency use authorization. Epidemiologist Ethel Maciel at the Federal University of Espírito Santo said the choice to release the vaccine data in different press conferences with vague numbers was harmful. “People started to be suspicious and were left with a lot of doubts that encouraged public mistrust on the vaccines,” says Maciel, who works on the federal vaccination plan. “We need more than ever to reduce moderate and severe cases, and for this purpose, the vaccine is very good,” she says. “But we will need a lot of people vaccinated to reduce transmission.”
科兴对照组感染率167/4599=3.63% moderna 对照组感染率：185/14366=1.23% 辉瑞对照组感染率：162/18325=0.89% 科兴巴西试验对象是医护人员，处于高传染风险环境。 辉瑞moderna是普通人群，对照组感染率区别说明巴西试验人员感染风险远高于美国试验人员（3-4倍）。 不是side by side的controlled 结果比较，就是apple vs orange. 毫无意义。
科兴对照组感染率167/4599=3.63% moderna 对照组感染率：185/14366=1.23% 辉瑞对照组感染率：162/18325=0.89% 科兴巴西试验对象是医护人员，处于高传染风险环境。 辉瑞moderna是普通人群，对照组感染率区别说明巴西试验人员感染风险远高于美国试验人员（3-4倍）。 不是side by side的controlled 结果比较，就是apple vs orange. 毫无意义。
我甚至怀疑如果依据原始数据，疫苗组和对照组的差距都在统计误差范围内，也就是说毫无用处... 国药集团的疫苗公布数据比科兴好得多。考虑到它们都是同类灭活疫苗，又都出于中国，要不然是国药技术更高，要不然是他们吹牛皮更厚
更新：方舟子说巴西人算错了，根据数据算出来的有效率是49.6%，不到50%。这个数字正好和50.4%互补。 国药集团至今没有公布三期数据，只有个三期中期有效率数字，想怎么说就怎么说
超輕症...
這名詞新鮮
前几天说78%有效的是什么疫苗呢
是国药的灭活疫苗。 问题是国药的数据在不同国家差距很大，属于薛定谔的疫苗
滅活病毒啊
薛丁諤的病毒
究竟是死的 還是活的.....
50%的efficacy是从200多个case里面算出来的，167安慰剂85疫苗。78%的efficacy是从38个case里面算出来的，31安慰剂7疫苗。所以有大量“不需要寻求医疗帮助”的轻症被排除了，不仅仅是排除掉无症状患者。
然后国药集团疫苗的免疫反应比科兴好是真的，有效性高一点也是应该的。
国药的数据应该主要来自阿联酋吧，他们的主要问题是只做了18-59岁的健康人，连高血压糖尿病都不让入组。一二期临床里面国药疫苗的免疫反应确实比科兴好。
Efficacy = 1-(85/4653)/(167/4599) = 49.69% Upper 95% CI = 1-exp(ln((85/4653)/(167/4599))-1.96*sqrt((1-85/4653)/85+(1-167/4599)/167)) = 61.13% Lower 95% CI = 1-exp(ln((85/4653)/(167/4599))+1.96*sqrt((1-85/4653)/85+(1-167/4599)/167)) = 34.89%
什么样的算重症？
陈将军去做mRNA疫苗了，药监局IND已经火速批了
https://www.chinanews.com/gn/2020/12-21/9367367.shtml
做大型临床试验是很难很难的。
Third time’s the charm? Brazil scales back efficacy claims for COVID-19 vaccine from China By Jon Cohen, Sofia MoutinhoJan. 12, 2021 , 5:50 PM Science’s COVID-19 reporting is supported by the Pulitzer Center and the Heising-Simons Foundation. In the third in a series of conflicting announcements about a Chinese-made COVID-19 vaccine candidate, Brazilian researchers reported today that the results of their efficacy trial were less impressive than they claimed last week. When analyzed by stricter criteria than used earlier, the vaccine’s efficacy against all forms of COVID-19, including mild cases, dropped from about 78% to 50%. The vaccine still appeared to give nearly 100% protection against disease severe enough to require hospitalization, although the trial amassed too few of those cases for that result to reach statistical significance. Commenting at the press conference today, microbiologist Natália Pasternak Taschner, president of the Question of Science Institute, a Brazilian nonprofit that aims to support public policy based on scientific evidence, said it was a “clear and clean study” and stressed that she wants the vaccine for herself and her parents. “We do not need to say this is the best vaccine in the world,” said Pasternak, who was not involved with the trial. “We have to say that this is our vaccine and it is a good vaccine to start the process of pandemic control.”
The vaccine, made by China’s Sinovac Biotech, contains a chemically inactivated version of SARS-CoV-2, the virus that causes COVID-19. At last week’s press conference that announced the 78% efficacy, Dimas Tadeu Covas, head of the Butantan Institute—a state-owned vaccinemaker in São Paulo that is conducting the study with Sinovac—offered few details. (Information was even sketchier in a press conference last month, when the team claimed only that the efficacy was greater than 50%.) But when pressed by journalists, he responded that this number came from about 220 cases of symptomatic disease. Today, researchers revealed that the 78% figure actually derived from analyzing COVID-19 cases in which people sought assistance for symptoms and tested positive for the virus—31 such cases among placebo recipients in the trial and seven in the vaccinated group. A more detailed analysis that included trial participants who tested positive but had symptoms so mild they did not seek help found 167 cases of COVID-19 in the placebo group and 85 in people who received the vaccine, for an estimated efficacy of 50.34%. Even allowing for statistical uncertainties, that is considerably below the greater than 90% efficacies of three other already authorized COVID-19 vaccines. But Esper Kallas, a study investigator based at the University of São Paulo’s main campus who spoke at the press conference, notes that because definitions of a positive case have varied among trials, “There may not be an accurate comparability between the studies.” In the Brazil trial, the liberal definition of a case “put things to the most difficult test,” said Ricardo Palácios of Butantan, who served as the clinical director of the study. “It is like comparing someone who runs a kilometer on paved ground versus someone running 1 kilometer with obstacles.” World Health Organization guidelines and those of several countries say a COVID-19 vaccine that has 50% efficacy with a lower bound of 30% meets the standards for initial authorization. “It has all the requirements to justify its emergency use,” Covas said. Brazil has one of the most devastating COVID-19 epidemics in the world, and Covas and several other speakers at the press conference said they hoped the Sinovac vaccine—which the Butantan is now producing—would promptly go into widespread use. No vaccine has yet received authorization in Brazil, but regulators are also reviewing efficacy data in one made by AstraZeneca and the University of Oxford. Covas said the reporting of the new data on the Chinese vaccine shows “our complete commitment and transparency in this process.” Earlier, Sinovac had asked Butantan not to release details of the study so the company could more closely analyze the data, leading to assertions that the Brazilian researchers had been muzzled by the company. Sinovac has not responded to repeated requests for comment from Science. Kallas notes the current case analysis only goes through 28 November 2020 and “much more” data are now available. Efficacy trials of the Sinovac COVID-19 vaccine are also underway in Turkey and Indonesia and have presented data that are even more preliminary. Researchers in Turkey reported on 24 December that they found 91.5% efficacy with its first 29 cases, and Indonesia reported 65% efficacy with 25 cases. Indonesia yesterday gave the vaccine emergency use authorization. Epidemiologist Ethel Maciel at the Federal University of Espírito Santo said the choice to release the vaccine data in different press conferences with vague numbers was harmful. “People started to be suspicious and were left with a lot of doubts that encouraged public mistrust on the vaccines,” says Maciel, who works on the federal vaccination plan. “We need more than ever to reduce moderate and severe cases, and for this purpose, the vaccine is very good,” she says. “But we will need a lot of people vaccinated to reduce transmission.”
跟据这篇文章，疫苗组没有需要住院的，最严重的是七个有症seeking assistance 的， 这个方是怎么划定重症的？不需要住院的也可以算重症？
她不是做腺病毒疫苗么？怎么又改了？难道看到牛津的结果知难而退了？
虽然不懂手动点赞
是啊，比较奇怪
那个腺病毒疫苗滴度不行，比灭活的还差呢；和加拿大引进的vector说的不一样，没有再跟进吧；国内做灭活疫苗相对还是有点底子的，当时选做灭活疫苗也是有考虑的。当然要说灭活疫苗能到80%以上是基本不可能的
4653+4599=9252 Sinovac report 里说的是9242个志愿者，但是两个组别加起来多了10个人，可能数据写错了。估计50.3是按9242算出来的
科兴巴西试验对象是医护人员，处于高传染风险环境。
辉瑞moderna是普通人群，对照组感染率区别说明巴西试验人员感染风险远高于美国试验人员（3-4倍）。
不是side by side的controlled 结果比较，就是apple vs orange. 毫无意义。
不知道你什么意思。
高风险意味着短期内对照组感染人数高，从而迅速完成临床试验。
兄弟，注意逻辑。
临床试验结束的标志是总感染人数达标。
临床试验的总人数越多，总感染人数达标时，群体感染比例越低。
巴西试验，总人数最少，所以要达到设定的感染人数，当然对照组感染比例高一些。
好像是陈将军的三期数据还没有公布
应该不是为了迅速完成实验的目的，高风险意味着接触病毒的几率大，滴度高，这种情况下需要疫苗产生的保护力够高才不会被感染。这个实验里不被感染的要求很高，和辉瑞的没有可比性的。
我是说方舟子逻辑不通。说医护人员身体更好青壮年更多，却无视医护人员是高风险。
我觉得不是这样的。
在小样本实验中，使用高风险人群才能迅速结束临床。
那个腺病毒早就完了你们不读文章么。。
我没觉得他逻辑不通。
瑞典有篇cell发现， 大概30-50%新冠患者的密切接触者没有发病，没有抗体，但是体内的免疫系统对新冠病毒有记忆。 换句话讲就是 接触过少量病毒的人可能更高更快更强的抵抗疾病，降低重症风险。
医护人员确实可能“抵抗力更好”。
https://www.cell.com/cell/fulltext/S0092-8674(20)31008-4
大概看了一下。结论很惊人，也很友好。我一般不信，等第二个study confirm。
哪里的文章，康希诺生物的胰腺新冠三期在墨西哥做的，最近的消息就是12月12日路透社发的。你在哪里听到康希诺三期的报告？
路透北京12月21日 - 中国国家卫生健康委员会医药卫生科技发展研究中心主任郑忠伟周一表示，中国康希诺生物已招募超过20,000名志愿者参与其新冠病毒疫苗的海外三期人体试验。
我对这些揪着国内疫苗天天责问的真的。。。
有这空可以呼吁一下美帝本土测序的工作吗？
测序不搞好，疫苗对新变异的作用不清楚，再呼吁快速打疫苗都是白搭呀
你还年轻吧？
方舟拿绿卡时，你还穿开裆裤呢，有可能还在吃奶呢。
几个月之前中和抗体的滴度就出来了啊。。
算了算时间，91年up贴主可能真的在。。。。。
科兴试验是在高风险的医护人员，因为感染率相对高一些，所以达到一定的感染数需要更少的参与者。这也是科兴trial的sample size只有一万多人。不管怎样，保护率是根据疫苗组和对照组（similar baseline demographics)的case来计算的。
数据都是他们自己放出来的，计算也有统一标准，选什么数值？
高风险是因为接触病患多，并不是这个群体本身给一样的病毒暴露条件是高风险，而这群人我相信高龄肯定少，方舟子逻辑没啥大问题，中国疫苗有效性不讨论，不严谨的讨论没什么意思
医护65以上的肯定少吧，只是接触病毒概率高
国药应该比科兴的好一点，但我现在也比较担心他们的数据了，因为CEO和总经理好像都辞职了。临阵换帅，不是啥好兆头。不过我之前在小浣熊mm的科普下，得出的猜想是“灭活疫苗有效性的天花板应该是牛津腺病毒的有效性（60%）",看来真的有可能。
这句话就搞笑了，你不觉得你的逻辑有问题嘛？国产疫苗的百分之九十多到五十多的有效率你难道不都是从媒体看到的，不报道好的那么百分之九十多的有效率的消息难道是你自己看发表的期刊上看到的？我明白你的意思，你是想特意指西方媒体，可我看到高到低西方媒体都有报道，不要信口开河好吗
是的呀 如果能做到迅速的全民接种绝对对病毒的传播能造成一定阻隔，张文宏就说现在追求的不是有效率，而是接种率。可惜，感觉国内总体策略是封堵，疫苗都是为了出口的。所以国内能不能，何时能进行全民接种计划，还是个大问号。毕竟国药和科兴加起来的年产能也才16亿（隔壁帖子说的），也就够8亿人，如果他们大部分还都出口了，估计能剩在国内的也就是毛毛雨了。也是因为他们要在国际上卖，即使是卖给第三世界国家，还是很纠结有效率的。所以不惜manipulate data.
医护人员对比其他行业（餐饮，零售， 建筑，食品加工，等）没有身体更好青壮年更多的优势。 但是一般认为医护人员是高风险。
医护高风险指的是exposure风险，不是转重症风险，和疫苗最该target的重症高风险群体是两回事。
大量一线医护像是住院医当然都必须是青壮年啊。
我怎么记得是陈将军的三期就根本没有国家愿意做， 一直听到的消息就是“三期临床在推进中”
一本正经的胡说八道，事实上医护人员的防护比普通人好得多。
胡搅蛮缠，寻白羽是认真的
据说塞尔维亚天津电建打了疫苗出国的400多人感染了300来号，是真的吗，如果是，疫苗无用
医护人员在高风险环境里也不是裸奔啊 各种PPE再加上比一般民众更注意保护自己
腺病毒疫苗不行，抗体滴度太低，那个 拿来的加拿大vector没有像发的paper那样的作用，应该已经没在做了，陈将军的军科在做国内的mRNA，这个说实话比腺病毒的靠谱，国内💰人力上去了买也应该能找出个免疫原性高的mRNA片段
是你的逻辑有问题。
医护高风险指的是exposure风险，不是转重症风险，和疫苗最该target的重症高风险群体是两回事。
大量一线医护像是住院医当然都必须是青壮年啊。
墨西哥做。
请问哪句是胡搅蛮缠？你自己先去把这两个试验的设计搞清楚再来反驳不迟。protocol 网上都有。
国药的有数据吗？本来觉得科兴比国药靠谱。但是起码科兴把数据都公布了吧
但是医护人员exposure 的机会比普通人高，而且毒素环境和浓度也比普通人要严重吧。
不是国内说mRNA 疫苗各种不好不安全吗？
你似乎忘了，比较有效率是和对照组比对的，如果对照组和接种组处于同一接触病毒同样风险下，至于是不是高还是低的风险没区别，要说区别就是暴露病毒风险高的会比较快达到揭盲的患者数，还有选择医生护士会比六十岁以上的人转重症比例低。明白了嘛？目的就是为了尽快揭盲
我一直的观点就是疫苗就应该百花齐放，数据公开透明。不管是灭活疫苗，mRNA疫苗，还是各种其他疫苗。而大家质疑中国疫苗的焦点就是数据不公开。 就算50%的有效率也是值得去打的和推广的，因为还有一个关键的减少重症率。 就好比流感疫苗，本身也就只有40-70%的有效率，不是也建议每年打吗，尤其是老年人。减少重症率就是减少死亡率，也能同时减轻医院的压力。因为mRNA 疫苗的运输要求很成本，灭活疫苗的确是给亚非拉国家提供了一个解决方案。目前欧美的情况，根本无暇顾及和帮助其他国家，中国的灭活疫苗能填了这个缺口。就是因为灭活疫苗需要给亚非拉重灾区的，所以数据的公开和准确才更重要，要不穷国家重灾区打了灭活疫苗以为是80/90%的有效率然后就不防护了，结果只有50%，那就是害人害己。
好像之前的78%是排除了所谓超轻症，现在把超轻症也算就50%了，超轻症不是无症状感染，还是有了症状才会去检测但不需要治疗的。如果无症状根本就不会去测，除非所有接种的和安慰组都去做检测，否则不可能发现无症状感染，而且必须查多次才找的到无症状，显然这是不现实的。另外其他疫苗也是不算无症状的。
问题是疫苗政治化， 要互相不质疑很难。你可以怪有些媒体说中国疫苗有效率低或者不可信，但请让数据公开，国药和科兴也没有公布全部数据，就别怪别人猜。国内媒体也别对辉瑞牛津等国外疫苗阴阳怪气的
那是因为陈将军没有率先研发出来
re 而且因为他们这样搞，数据，流程都不够公开，对公布的结果进行筛选，会让人甚至质疑它50%的数据的真实可靠性。你一上来就说有效性50%，临床症状有效性70%，重症有效性90%+，其实就很好了。可惜领导非得跟欧美的疫苗比，现在只能打脸。毕竟技术的差异性在这里，灭活本来就做不到很高。。。
但他们防护也更多啊，一定程度上offset 毒素浓度。而且exposure 风险高和重症风险高完全是两回事，那个人在混肴视听。疫苗最重要的target群体应该是重症高风险群体，所以一直说最需要疫苗的是老年人和有基础病患者。
你发现没有，现在国内攻讦mRNA疫苗的没有官方。只不过是官方放出来的自媒体或者科技工作者。 这是老操作了，一方面起到洗脑效果，一方面给自己留后路。 将来mRNA Available而且国内需要的时候，又会出来辟谣的。 当然有可能那个时候中国之外已经群体免疫，就不了了之了。
市面上每个疫苗，辉瑞牛津moderna哪个不是被全世界在显微镜下盯着，所以数据更要公开透明。
没钱呗。做三期要花不少钱的。找志愿者，找医生等。
胡搅蛮缠， “寻白羽”是认真的
对不起，我应该给“寻白羽”这三个字划重点。 就你还认认真真地回他帖子
中国的疫苗可以科兴自己公开数据啊。。谁的疫苗谁负责。。没意义咋不敢公开呢