COVID-19からの回復した人の抗体レベルが低いとの報告

新型コロナウイルス感染症から回復した人のうち 3分の1で抗体レベルが低いという報告
中国・復旦大学の研究チームにより、新型コロナウイルス感染症(COVID-19)から回復した人の中に、新型コロナウイルス(SARS-CoV-2)抗体レベルが低い人が少なからず含まれたことが報告されています。論文は査読を経たものではなく「臨床の指針とすべきではない」とのことですが、内容は今後のワクチン開発などに影響を及ぼす可能性があります。
病気から回復した人の血漿にはウイルスに対する抗体が含まれていて、「スペイン風邪」こと1918年のインフルエンザやエボラ出血熱の際に治療に使用されたことがあります。
これと同じように、新型コロナウイルス感染症から回復した人の血漿には新型コロナウイルスへの抗体が含まれていると考えられ、実際に臨床試験への取り組みが進められています。
しかし、復旦大学の研究チームによると、上海公衆衛生臨床センターから退院した175人の患者の血液サンプルを分析した結果、ほぼ3分の1にあたる患者のサンプルで、抗体のレベルが予想以上に低かったことがわかったとのこと。そのうち10人は、ラボで検出できないほど抗体レベルが低かったそうです。
調査の対象となったのは、すべてが軽度の症状から回復したばかりという人。これは、集中治療室に入っていた患者の多くはすでに抗体が確認されていたためです。調査の結果、抗体レベルは年齢が高いほど上昇し、60歳～85歳の患者は、15歳～39歳の患者と比べて抗体量が3倍以上でした。
研究チームは「これらの患者の再感染リスクが高いかどうかは、さらなる研究で調べる必要がある」と述べています。
今回の新型コロナウイルスでは、一度感染症から回復した人が再感染したという報告が出ており、長期にわたって向き合っていくことになるという覚悟が求められそうです。
https://www.scmp.com/news/china/science/article/3078840/coronavirus-low-antibody-levels-raise-questions-about

まあ要するにぶり返す「ただの風邪」みたいなもんですな。

要するに若い健康な人は感染しても自然免疫でなんとかなるので抗体をつくる必要が無いわけですな。
不健康な年よりほど回復するには抗体が必要になるわけですが、場合によってはコレが免疫システムの暴走と関係あるかもしれませんね。だとするとワクチンは難しいかもね。集団免疫も・・・（爆ｗｗｗｗｗｗｗ

Coronavirus: low antibody levels raise questions about reinfection risk

Scientists in Shanghai say some recovered patients show no signs of the neutralising proteins
Early-stage findings could have implications for vaccine development and herd immunity, they say
Stephen Chen in Beijing
Published: 10:00pm, 7 Apr, 2020
Updated: 6:28am, 8 Apr, 2020

Researchers in Shanghai found low levels of coronavirus antibodies in some people who had recently recovered from Covid-19.
Researchers in Shanghai hope to determine whether some recovered coronavirus patients have a higher risk of reinfection after finding surprisingly low levels of Covid-19 antibodies in a number of people discharged from hospital.

A team from Fudan University analysed blood samples from 175 patients discharged from the Shanghai Public Health Clinical Centre and found that nearly a third had unexpectedly low levels of antibodies.

In some cases, antibodies could not be detected at all.

“Whether these patients were at high risk of rebound or reinfection should be explored in further studies,” the team wrote in preliminary research released on Monday on Medrxiv.org, an online platform for preprint papers.

Although the study was preliminary and not peer-reviewed, it was the world’s first systematic examination of antibody levels in patients who had recovered from Covid-19, the disease caused by the coronavirus, the researchers said.

All of the patients had recently recovered from mild symptoms of the disease and most of those with low antibody levels were young. The researchers excluded patients who had been admitted to intensive care units because many of them already had antibodies from donated blood plasma.

Antibodies are generated by the immune system and have unique chemical structures to inhibit specific pathogens. The coronavirus antibody intercepts the spike protein on the viral envelope to prevent it from binding with human cells.

The researchers said they were surprised to find that the antibody “titer” value in about a third of the patients was less than 500, a level that might be too low to provide protection.

“About 30 per cent of patients failed to develop high titers of neutralising antibodies after Covid-19 infection. However, the disease duration of these patients compared to others was similar," they said.

The team also found that antibody levels rose with age, with people in the 60-85 age group displaying more than three times the amount of antibodies as people in the 15-39 age group.
The low amounts of antibodies could affect herd immunity
, resistance to the disease among the general population to stop its spread.

“This is a clinical observation we made at the front line. What this will mean to herd immunity will require more data from other parts of the world,” Professor Huang Jinghe, the leader of the team, said on Tuesday.

Huang said 10 of the patients in the study had an antibody presence so low it could not even be detected in the laboratory.

These patients experienced typical Covid-19 symptoms including fever, chill and a cough, but might have beaten back the virus with other parts of the immune system such as T-cells or cytokines.

How they did this was still unclear.

“Vaccine developers may need to pay particular attention to these patients,” Huang said. If the real virus could not induce antibody response, the weakened version in the vaccine might not work in these patients either.

The researchers also found that the Covid-19 antibody could bind with a distantly related strain that caused an outbreak of severe acute respiratory syndrome (Sars) in 2003.

But the binding could not suppress Sars virus replication in cells, dashing hopes of developing a vaccine for two or even more coronavirus strains at once.

Many questions about the virus remain unanswered, including how the virus made the jump from animal to humans; why some people die from Covid-19 and others are asymptomatic; and why some recovered patients test positive again.

Professor Wang Chen, a senior scientific adviser to the central government, told state media on Monday that it was way too early to declare victory against the disease even in China, where the situation was under control for now.

“Who knows whether this will become something like a seasonal flu, or chronic disease like hepatitis B, or just vanish like Sars?” he was quoted in the official Science and Technology Daily.

“Up till now we still lack imagination [to tell].”
https://www.scmp.com/news/china/science/article/3078840/coronavirus-low-antibody-levels-raise-questions-about?li_source=LI&li_medium=homepage_int_edition_top_picks_for_you

2020年3月26日木曜日
「ただの風邪」たるKung Fluに対してワクチンはないし「ただの風邪」でも弱ってる香具師は死ぬ
http://tokumei10.blogspot.com/2020/03/kung-flu_26.html


site://tokumei10.blogspot.com ただの風邪


、、、（爆ｗｗｗｗｗｗｗｗｗｗ