We already knew for a while now that mutations that include E484K are likely going to require a booster shot. I mentioned in a previous post that Moderna has played catch up to Pfizer vaccine in most areas, but is a bit ahead on the booster shot research than Pfizer. Of course, this doesn't mean it'll be the dinner down the road, but I think we should take whatever advancements we can get. Eek mutations are indeed worrisome and has defeated AZ vaccine, and shows reduce Novavax‘s efficacy, there are also encouraging data that mRNA vaccines may still produce sufficiently elevated titer and cellular memories to guard against this variant (which is at least for now, I'm basing my recommendation on evidence-based medicine to slightly favors Pfizer's vaccine)。 https://www.nature.com/articles/d41586-021-01222-5 It's still a race between the virus and mankind. The virus has ran amok for a while now, we are finally winning some victories using vaccines (the 4th wave causes a merely 10% rise before hospitalization fell again where I am, and now it's on the decline again as vaccination is winning), But I'm also too aware of the proverbial saying that "hubris comes before the fall". While I'm finally optimistic that the virus can't cause any major "waves" at least in the vaccinated majority or the healthcare system, I reluctant to proclaim victory until I can speak with certainty. I wish you and I the best, my friend. And not just for us, but for the entire mankind, may we ultimately find a cure and eradicate COVID like we did with smallpox, also at my lowest expectation limit to a seasonal illness like the flu.
We already knew for a while now that mutations that include E484K are likely going to require a booster shot. I mentioned in a previous post that Moderna has played catch up to Pfizer vaccine in most areas, but is a bit ahead on the booster shot research than Pfizer. Of course, this doesn't mean it'll be the dinner down the road, but I think we should take whatever advancements we can get. Eek mutations are indeed worrisome and has defeated AZ vaccine, and shows reduce Novavax‘s efficacy, there are also encouraging data that mRNA vaccines may still produce sufficiently elevated titer and cellular memories to guard against this variant (which is at least for now, I'm basing my recommendation on evidence-based medicine to slightly favors Pfizer's vaccine)。 https://www.nature.com/articles/d41586-021-01222-5 It's still a race between the virus and mankind. The virus has ran amok for a while now, we are finally winning some victories using vaccines (the 4th wave causes a merely 10% rise before hospitalization fell again where I am, and now it's on the decline again as vaccination is winning), But I'm also too aware of the proverbial saying that "hubris comes before the fall". While I'm finally optimistic that the virus can't cause any major "waves" at least in the vaccinated majority or the healthcare system, I reluctant to proclaim victory until I can speak with certainty. I wish you and I the best, my friend. And not just for us, but for the entire mankind, may we ultimately find a cure and eradicate COVID like we did with smallpox, also at my lowest expectation limit to a seasonal illness like the flu.
We already knew for a while now that mutations that include E484K are likely going to require a booster shot. I mentioned in a previous post that Moderna has played catch up to Pfizer vaccine in most areas, but is a bit ahead on the booster shot research than Pfizer. Of course, this doesn't mean it'll be the dinner down the road, but I think we should take whatever advancements we can get. Eek mutations are indeed worrisome and has defeated AZ vaccine, and shows reduce Novavax‘s efficacy, there are also encouraging data that mRNA vaccines may still produce sufficiently elevated titer and cellular memories to guard against this variant (which is at least for now, I'm basing my recommendation on evidence-based medicine to slightly favors Pfizer's vaccine)。 https://www.nature.com/articles/d41586-021-01222-5 It's still a race between the virus and mankind. The virus has ran amok for a while now, we are finally winning some victories using vaccines (the 4th wave causes a merely 10% rise before hospitalization fell again where I am, and now it's on the decline again as vaccination is winning), But I'm also too aware of the proverbial saying that "hubris comes before the fall". While I'm finally optimistic that the virus can't cause any major "waves" at least in the vaccinated majority or the healthcare system, I reluctant to proclaim victory until I can speak with certainty. I wish you and I the best, my friend. And not just for us, but for the entire mankind, may we ultimately find a cure and eradicate COVID like we did with smallpox, also at my lowest expectation limit to a seasonal illness like the flu.
但是从另外一方面来看，南非变种逃逸的科技树点的太多，导致传播能力不佳，在几乎所有地区都被英国变种给挤得抬不起头来。目前看逃逸能力和传播能力比较平衡的可能还是巴西变种和印度变种，能够造成一部分二次感染和疫苗的breakthrough，同时传染性增强、对没打过疫苗的年轻人和小孩的感染能力增加。事实上巴西变种在美国的比例尽管很小，但是增加速度是很快的，这个趋势很不好。
下图是Novavax在南非实验中的一个附带结果：得过新冠和没有得过新冠的人在南非变种大流行中感染率的变化，可以看到既往感染基本上完全没有办法防止南非变种造成的有症状感染。
2， 疫苗还有没有用？疫苗针对各个变种的体外实验已经做了很多了，目前看来南非变种对中和滴度的影响最大，能够让mRNA疫苗产生的中和滴度下降3倍到十几倍（下降多少和用的真病毒还是假病毒种类有关，假病毒又有很多种）。另外还发现大量接种过牛津疫苗或者灭活疫苗的血清对南非变种完全失去了中和能力。而且牛津疫苗在南非的实战中也失败了，基本上无法避免有症状感染。
不过中和滴度测的是体液免疫，而mRNA疫苗和腺病毒疫苗产生的细胞免疫都是不能忽略的，前几天有文章检测了接种mRNA疫苗之后特异性T细胞对各个变种的识别能力，发现几乎没有变化，T细胞可以识别几乎所有的变种。CD8+ T细胞可以直接杀死被感染细胞，但是CD4+ T细胞的作用是“教育”B细胞生产正确的抗体，这个过程需要时间，所以单靠T细胞免疫很难完全避免所有的有症状感染。下面的图是T细胞对各个变种的识别能力的对比，红色是南非变种。
另外昨天NEJM发表了第一个Pfizer疫苗针对南非变种的大规模实战结果，在卡塔尔做的，经过平行对比发现接种过疫苗的人核酸检测出南非变种阳性的概率下降了75%，检测出英国变种阳性的概率下降了90%。另外对重症的保护作用非常高，在南非和英国变种导致的200多个breakthrough case里面没看到一个重症。注意这个统计测的是核酸阳性，里面包括了一些无症状感染，有效率会比只测有症状感染的时候低一些。因此我们基本上可以得出结论：南非变种对mRNA疫苗的短期有效率影响不是非常严重。
3，变种对疫苗的长期影响怎么样？昨天Moderna在press release里面公布了一些很重要的信息，接种mRNA疫苗6-8个月之后，半数的人的血清对南非变种的中和能力下降到了检测的下限（一般是滴度10到40之间）。前面已经说过CD4+ T细胞可以减少重症，但是很难避免所有的有症状感染，因此现在的两个mRNA疫苗针对变种的长期有效性会受到严重的影响。
https://investors.modernatx.com/news-releases/news-release-details/moderna-announces-positive-initial-booster-data-against-sars-cov
Moderna同时还检测了他们第三针booster shot的效果，booster shot的剂量是50微克，前两针的一半。发现用南非变种做的booster shot可以同时大幅增强对wild type和南非变种的中和能力。这是一个很重要的结果，说明mRNA疫苗没有看到"免疫原罪”的问题，疫苗能够刺激免疫系统对新的抗原产生反应。我觉得如果带有E484K突变的变种（比如巴西变种）在美国流行起来的话，一年后需要加强第三针是个大概率事件。
有理有数据。赞
逃逸疫苗的能力不那么强，但是杀伤力和传染性还是不可小觑。对于家有小娃必须上学的，还是个挺大的威胁。
针对小孩的疫苗啥时候能出啊OTL
目前英国作为变种研究比较透彻的地方。 对于南非变种的追踪和恐惧程度是最深的，封了一大堆非洲国家。反而对于印度变种大家虽然一开始特别严肃，但是慢慢发现其实没啥，几波回来的印度裔也没因为这个变种发生什么太严重的事情，最近也没有对其他有印度变种的地方加以严格封锁。现在看，印度搞成现在这样，最大的问题还是疫苗普及率太低和医疗崩溃。
抗生素是对抗细菌的 不一样的
青霉素自打问世，救了无数人命，怎么能说没用。是的，细菌也会进化出抗药性，所以抗生素不能滥用；但是没有抗生素的世界一定比现在要悲惨得多。想想欧洲的黑死病。
如果“和谐共处”的代价就是要牺牲那么大的一部分生命，人类不想接受这个代价而极力抗争很正常。
我也想问这个问题。刚搜了一下：
抗原原罪(英文：original antigenic sin)，又称霍斯金现象(Hoskins effect)，[1] 是指身体免疫系统在遭遇到与初次感染有些微不同的外来物(如：病毒或细菌)时，倾向利用初次产生的免疫记忆，而非再次产生免疫反应的一种特性。这会使免疫系统“受制于”初次抗原引起的免疫反应，而不能针对之后的抗原感染产生最有效的反应(前提是两次接触的不同抗原仅能有些许差异)。抗原原罪的现象被认为与流感病毒、、(HIV)和其余一些病毒有关。
抗原原罪现象 抗体依赖增强（ADE---antibody-dependent enhancement的）作用： 病毒感染都是从黏附于细胞表面开始的，黏附是通过病毒表面蛋白与靶细胞上特异性受体和配体分子的相互作用来完成的。 针对病毒表面蛋白的特异性抗体常常可以阻抑这一步骤，将病毒“中和”,使其失去感染细胞的能力。然而在有些情况下，抗体在病毒感染过程中却发挥相反的作用：它们协助病毒进入靶细胞，提高感染率，这一现象就是抗体依赖性增强作用。ADE效应 大致意思是：第一次感染后免疫反应造成的免疫系统记忆，会负面影响以后感染相似病毒的免疫过程，即抗原原罪。 病毒a感染机体后，免疫系统产生了针对病毒a抗体A，这个抗体A对病毒a有特效，能够快速消灭病毒a 病毒a侵入——制造抗体A——效果拔群——免疫成功 但是如果病毒a变异了，而且是稍稍变异成相似的病毒a''''，免疫系统就会很容易识别错误，把病毒a''''仍然当做病毒a，习惯性地继续生产抗体A，这个A是不能像对付a一样有效地消灭a''''的 病毒a变异成a''''——病毒a''''入侵——仍然制造抗体A——效果不佳——免疫失败 而且更可怕的是，免疫系统在制造抗体A的过程中，会大大抑制对病毒a''''的识别和有效抗体A''''的制造过程 制造抗体A——抑制机体对病毒a''''的识别与抗体A''''的制造——雪上加霜 相当于免疫系统说：这病毒我见过，身体不用再去识别这个病毒a（实则病毒a''''）了，直接制造抗体A来消灭它们吧（一脸自信 ）
上面是知乎上的回答。但具体联系到楼主妹妹提到的mDNA疫苗需要打第三针才能有效对付其它变种，我还是不太明白这与＂抗原原罪＂有何关系。希望楼主妹妹再给我们解释一下。— 刚刚看到楼主妹妹的最新回答，明白了。谢谢！
不会引起ADE.
免疫系统是有记忆性的，之前大家担心的一种可能是接种了针对南非变种的booster shot之后身体生成的还是针对wild type的抗体，并不能解决新变种的问题，也就是所谓的免疫原罪。但是现在看这个问题好像并没有出现。
照你这么想那人类的平均寿命还只能是40、50岁不到。你比较适合生活在原始社会
你这么非黑即白干什么？楼主的措辞那么谨慎，科学家都不确定的事情，你对我人身攻击干吗？ 一定要所有人一种想法吗？要辩论就理性一点好吗？
病毒出现变种就是没措施克制病毒的恶果。疫苗抑制病毒的自我复制，其实是大大减小了出现变种的机会。你听说以色列出过什么抗疫苗的变种吗？英国、南非、巴西、印度、加州都是让病毒肆虐才会出这档子事。
把病毒跟叛逆期青少年比，倒是挺感性的，不过肯定不是科学家的理念。XD
你咋这么确定呢？如果这么确定，为啥欧洲一早就表明了佛系抗议？变异也不是这么快的好吧？ 说白了这病毒就是拼基因，拼身体。其实残酷一点地说就是自然选择。只是这个是政治不正确而已。 辉瑞研究疫苗的科学家不同意疫苗，辞职了知道吧？多看看正反面，没什么坏处。
其实楼主的信息量太大了，很多我看完还是不懂。
你连抗生素都不是很赞同啊？ 这个问题就严重了。一个小小的cut就可能导致死亡。
虽然你看不懂，但是并不妨碍你发很多关于新冠疫苗的帖子。
弱问为什么mRNA疫苗和腺病毒疫苗产生细胞免疫，而感染病毒本身不会产生细胞免疫呢？是因为这个病毒会搞死T cell，所以细胞免疫存不下来？
谢谢科普！手动点赞！
有个后续问题，您之前提到重组蛋白技术的T细胞免疫反应不如mRNA技术，这种不如是“显著”下降吗？为什么？重组蛋白不也会注入“伪装”过后的Spike protein让免疫系统生成T细胞来对抗吗？
希望novavax能在秋冬季给上学的小孩子们用上，不知道还靠谱不。
Eek mutations are indeed worrisome and has defeated AZ vaccine, and shows reduce Novavax‘s efficacy, there are also encouraging data that mRNA vaccines may still produce sufficiently elevated titer and cellular memories to guard against this variant (which is at least for now, I'm basing my recommendation on evidence-based medicine to slightly favors Pfizer's vaccine)。 https://www.nature.com/articles/d41586-021-01222-5
It's still a race between the virus and mankind. The virus has ran amok for a while now, we are finally winning some victories using vaccines (the 4th wave causes a merely 10% rise before hospitalization fell again where I am, and now it's on the decline again as vaccination is winning), But I'm also too aware of the proverbial saying that "hubris comes before the fall". While I'm finally optimistic that the virus can't cause any major "waves" at least in the vaccinated majority or the healthcare system, I reluctant to proclaim victory until I can speak with certainty.
I wish you and I the best, my friend. And not just for us, but for the entire mankind, may we ultimately find a cure and eradicate COVID like we did with smallpox, also at my lowest expectation limit to a seasonal illness like the flu.
闲着不要光瞎想，多读读论文，学学什么是科学实验，怎么理解实验结果。不要只是看新闻看热闹。你这个想法听起来就特别没有科学逻辑。
没错，特别反智，还自觉高明。
这样科学的文章应该飘红置顶！
感谢层主分享最新文章和自己观点。版上藏龙卧虎！
顶楼主，辛苦了
写的真好👍
感谢科普，有理有据
是的。孩子们是未来是希望