コロナに故意に接触させ発症を観察　英で新研究へ、世界初か

【ロンドンＡＦＰ＝時事】英国の研究班は20日、健康な人々を新型コロナウイルスに接触させ、同ウイルス感染症の発症に至るウイルス量を特定する研究に着手する計画を発表した。同班は、世界初の試みだとしている。（写真は資料写真）
　研究母体は、インペリアル・カレッジ・ロンドンなどが参加する「ヒューマン・チャレンジ・プログラム」。
　被験者として、心疾患や糖尿病、肥満などの基礎疾患がない１８～３０歳のボランティアを募集する。
　インペリアル・カレッジの発表によると、「この初期段階では、人に新型コロナウイルス感染症を発症させるウイルスの最少量を見つけることが狙い」だという。
　研究成果は、ワクチンの作用の仕方の調査や、有望な治療法の模索に生かされる。
　同大のピーター・オープンショー教授（実験医学）は２０日、ＢＢＣラジオ４で、被験者のウイルスへの接触は鼻から行うと明かした。
　「こういったボランティアを対象とした研究の大きな利点は、感染時だけでなく感染前の様子も一人一人注意深く観察し、各段階で何が起きているかを正確に調べられることだ」と話している。
　また同大の感染症部門は、「われわれの最優先事項は、ボランティアの安全だ」としている。
　研究班の話では、被験者を故意に感染させるため「ワクチン接種済みの人がウイルスに感染しにくくなるかどうかを調べることで、効果の立証を非常に迅速に始めることが可能になる」という。
　研究は、来年初めに開始される予定。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2020/10/21-13:09）

British researchers on Tuesday said they hope to expose healthy volunteers to the virus that causes Covid-19 in a groundbreaking study to discover the amount needed for people to become infected.
The Human Challenge Programme -- a partnership that includes Imperial College London -- hopes the work will ultimately help to reduce the spread of the coronavirus, mitigate its impact and reduce deaths.
In what researchers called a world first, the opening stage of the project will examine the possibility of exposing healthy volunteers to the SARS-CoV-2 coronavirus.
They aim to recruit volunteers between the ages of 18 and 30 with no underlying health conditions such as heart disease, diabetes or obesity.
In this initial phase, the aim will be to discover the smallest amount of virus it takes to cause a person to develop Covid-19, Imperial College said in a statement.
The volunteer would be infected via the nose, Peter Openshaw, professor of experimental medicine at Imperial, told BBC Radio 4 on Tuesday.
The great advantage of these volunteer studies is that we can look at each volunteer very carefully not only during the infection but also prior to infection, and we can work out exactly what's going on at every stage, he added.
The researchers would use the results to study how vaccines might work and to explore potential treatments.
Because the study deliberately infects the volunteers, it should be possible for scientists to begin to establish efficacy very quickly, by testing if those who have had a vaccine are less likely to become infected with the virus, explained the researchers.
Our number one priority is the safety of the volunteers, said Chris Chiu, from Imperial's department of infectious disease.
No study is completely risk free, but the Human Challenge Programme partners will be working hard to ensure we make the risks as low as we possibly can.
The UK's experience and expertise in human challenge trials as well as in wider COVID-19 science will help us tackle the pandemic, benefiting people in the UK and worldwide, he added.
The study is expected to begin early next year, said the research team from the partnership, which also includes the government, a clinical company and a hospital.