日本可能已经达成群体免疫，整个过程死亡极低

[贵圈]

日本人口密度如何，大家不用争了，按理说应该很惨，
而且，日本基本上没有lockdown。按理说应该很多
更甚，日本料理依赖冷冻肉类，按理说很难逃过各种爆发。

但是

日本第一波就不多，第二波很早到来，八月初。
还是不多。第二波已经接近尾声。

整个过程几乎没有lockdown，上班上学、、、、

死亡率呢

可以说是极低。考虑到日本人口老龄化严重，这不合常理。

 

[贵圈]

日本依靠什么？

1. 亚洲人Race? 中国差不多的race但是武汉。。。之后需要严厉的封城，追踪。
2. 日本人的自律？德国人也自律，数据就差很多
3. 日本人认真trace追踪
4. 日本人是口罩控。长时间戴口罩，严格戴。人人戴。日本首相在公务露面时，有时不戴。工作需要。

 

[贵圈]

为什么说最终日本城市已经达成了群体免疫呢？
Tokyo citizens may have developed COVID-19 herd immunity, say researchers

• Download PDF Copy

By Sally Robertson, B.Sc.Sep 24 2020
Researchers in Japan and the United States have conducted a study showing that herd immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have developed among the citizens of Tokyo during the summer.

Study: Dynamic Change of COVID-19 Seroprevalence among Asymptomatic Population in Tokyo during the Second Wave. Image Credit: StreetVJ / Shutterstock
SARS-CoV-2 is the viral agent responsible for the current coronavirus disease 2019 (COVID-19) pandemic that is continuing to sweep the globe, posing significant threats to human health.
Yasutaka Hayashida (Medical Corporation Koshikai, Tokyo) and colleagues from Boston Children’s Hospital and Beth Israel Deaconess Medical School, Boston, say their study suggests that seroprevalence for SARS-CoV-2 rose to almost 50% at around the same time cases of COVID-19 waned in the city.

“With the rise in SPR [seropositivity rate] nearing 50% within our cohort, matching the time when COVID-19 cases waned, the possibility of herd immunity should be considered, particularly in the highly-dense urban scenario like Tokyo,” writes the team.

A pre-print version of the paper is available in the server medRxiv*, while the article undergoes peer review.

The seropositivity rate and 7 days moving average of daily confirmed new cases of COVID19 from 5/26 to 9/1
Death rate in Japan fell, despite no lockdown
Compared with the United States and European countries, COVID-19-related mortality has been low in Japan, and the death rate has fallen despite the absence of a lockdown.
The reasons for the low fatality rate are not yet known. They may be related to a low SARS-CoV-2 prevalence across the general population or decreased rates of fatality among infected cases.
Distinguishing the underlying factors requires SARS-CoV-2 prevalence data, particularly data that represent the asymptomatic general population.

“Serological tests monitored across the course of the second wave can provide insights into the population-level prevalence and dynamic patterns of COVID-19 infection,” writes the team.

What did the current study involve?
To estimate seropositivity for SARS-CoV-2 throughout the summer, the team enrolled 1,877 healthy, asymptomatic employees of large company from 11 disparate locations across Tokyo.
Related Stories

• 23 SARS-CoV-2 strains circulating in the Philippines
• SARS-CoV-2 D614G variant enhances infectivity, replication and transmission
• Evaporation is critical for coronavirus transmission in colder months

Across the company, serology tests for SARS-CoV-2-specific immunoglobulin G (IgG) and IgM antibodies were performed weekly between May 26th and August 25th, 2020. This time window incorporated the well-documented “second wave” of COVID-19 that occurred in Japan.
To estimate seroconversion and seroreversion among the general population in Tokyo over time, the tests were offered to each participant twice, separated by around a month.
The seropositivity rate was calculated by pooling data from each two-week window across the cohort. Changes in immunological status against SARS-CoV-2 were determined by comparing results between two test results obtained from the same participant.
Six hundred fifteen individuals, aged a mean of 40.8 years, underwent one test, and 350 of those (aged a mean of 42.5 years) underwent two tests.
Seropositivity dramatically increased over the summer
The seropositivity rate increased from 5.8% at the beginning of the study to an unexpectedly high 46.8 % by the end of the summer.

“A high seropositivity rate in Tokyo may not be fully unexpected given its remarkably high population density, tight spacing, the widespread use of public transportation, and no implementation of a lockdown,” say Hayashida and colleagues.

Of the 350 individuals who underwent both tests, 54 (21.4 %) of 252 who were initially seronegative were seropositive by the time they completed the second test. Of the remaining 98 individuals who were seropositive on initial testing, 12 (12.2%) became seronegative.

“Seroreversion was not infrequent, seen in 12% of participants over the one-month span between tests,” says the team. “This suggests that serological testing may significantly underestimate past COVID-19 infections, particularly when applied to an asymptomatic population.”

The findings can be generalized to the broader metropolitan area
The researchers say that although the study cohort was not selected from a broader, random population sample in Tokyo, the findings can still be generalized to the greater metropolitan area for a number of reasons, including the multiple disparate locations participants were from and the limited physical contact they had with each other.
Furthermore, the exclusion of symptomatic individuals could potentially have led to an underestimation of the overall seropositivity rate.
The possibility of herd immunity should be considered
“COVID-19 infection may have spread widely across the general population of Tokyo despite the very low fatality rate,” say Hayashida and team.
Although Japan took the atypical step of not implementing a mandatory lockdown, the second wave peaked and subsided nevertheless, they add.

“Given the temporal correlation between the rise in seropositivity and the decrease in reported COVID-19 cases that occurred without a shut-down, herd immunity may be implicated,” suggest the researchers.
“Future studies may consider evaluating whether lifestyle/habits, viral strain, the widespread use of masks, or host factors such as immunological memory are responsible for the observed low fatality,” they conclude.

*Important Notice
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
Journal reference:

• Hayashida Y, et al. Dynamic Change of COVID-19 Seroprevalence among Asymptomatic Population in Tokyo during the Second Wave. medRxiv, 2020. doi: https://doi.org/10.1101/2020.09.21.20198796

 

[Anakin]

日本人戴口罩可听话了

 

[贵圈]

their study suggests that seroprevalence for SARS-CoV-2 rose to almost 50%。
那些认定群体免疫还要死几十万人的科学家，滚一边羞愧去吧。

 

[贵圈]

现在分析原因

1. 感染率低，而且度过二波，依然很低。
口罩
群体免疫

2. 死亡率低
口罩
全体免疫
医疗发达


哪么为什么口罩狂人，能够达成群体免疫呢？

因为口罩不能完全阻止病毒。极少量，进入人体，产生无症状，mild症状感染。反而促成了群体免疫

 

[贵圈]

结论：

1.全民戴口罩，是无上大法。
2. quantity matters，少吸入病毒，有益无害。
3. 群体免疫口罩大法，完全不会损坏经济活动。不需要lockdown。
4. 加拿大美国没有办法lockdown的国家，必须开始认真研究第二波之下，真正的传染病学。也就是所谓的不封城，不停工，口罩大法。最终促成群体免疫

如果国家层面严格口罩规则，经济回归指日可待。

 

[贵圈]

日本口罩文化到了什么程度，室内长时间佩戴。室外除了体育运动，一直佩戴。

 

[CastleCode]

那就告诉土豆别发钱了，发口罩每人每天两个

 

[枫国冰都]

不能那么说的。传染源经过几代传染后，病毒性会下降，致死率会降低，这是很正常的。不要TMD鼓励什么群体免疫，医院受得了吗？

 

[gocanoeing]

怎么没提到HCQ的作用

 

[贵圈]

主要是立法执法去促成文化习惯的改变。

目前，受教育的加拿大人大口罩已经普及，底层人士有些还在抗拒，但是，给与惩罚和奖励双重推动，应该有希望。

美国，宗教，拥枪，贫民和种族问题。四大问题，是的美国管制几乎不可能。美国必须发展另一种模式的群体免疫。

 

[贵圈]

不能那么说的。传染源经过几代传染后，病毒性会下降，致死率会降低，这是很正常的。不要TMD鼓励什么群体免疫，医院受得了吗？

你不懂，微量病毒透过口罩吸入，导致的轻微症状，不会给医院带来任何压力。加拿大实际上就是在执行这种策略，而且，有可能要公开推行。

 

[CastleCode]

在有疫苗之前最好的办法是靠自觉或者管控，日本是靠自觉，中国是靠管控，效果都不错。其它国家都做不到，只能靠硬抗了

 

[rottenmelon]

你不懂，微量病毒透过口罩吸入，导致的轻微症状，不会给医院带来任何压力。加拿大实际上就是在执行这种策略，而且，有可能要公开推行。

圈哥这么明白人，到现在加拿大这边你还没闹明白怎么回事儿？
加拿大人戴口罩完全没有问题，
现在这完全成为问题难道没带点政治因素？议会不开一党独大，不要太爽，某些党派巴不得最好再来第三波第四波才好。