モデルナ製ワクチン、６～１１歳にも有効か　強い免疫反応確認

【ワシントンＡＦＰ＝時事】米製薬大手モデルナは２５日、同社が開発した新型コロナウイルスワクチンの６～１１歳を対象とした臨床試験（治験）の結果、強い免疫反応と安全性が確認されたと発表した。治験データは近く各国の規制当局に提供するとした。（写真は米製薬大手モデルナ製の新型コロナウイルスワクチンが入った箱）
　４７５３人の子どもを対象に実施された中・後期治験の暫定分析結果では、２回の接種後、有効性の指標である「中和抗体」の高い産生量が示された。中和抗体はＹ字形のタンパク質で、新型ウイルスの細胞侵入を阻止する働きがある。
　ワクチン投与量は成人の半分の５０マイクログラムだったが、抗体産生量の平均は通常量を投与された若年成人の１．５倍だった。副反応の大半は軽度～中等度で、倦怠（けんたい）感や頭痛、発熱や接種部位の痛みが含まれる。ワクチンの有効性の評価は今回の発表内容に含まれておらず、発症例の報告が集まった後に公表される見通しだ。
　米政府の諮問委員会は２６日に開く会合で、米ファイザー製ワクチンの５～１１歳への使用承認について議論する予定。米国立アレルギー感染症研究所（ＮＩＡＩＤ）のアンソニー・ファウチ所長は、１１月中旬までには同年齢層を対象とした接種が開始できるとの見通しを示している。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2021/10/26-17:02）

US biotech firm Moderna said Monday its Covid vaccine was safe and produced a strong immune response in children aged 6-11, adding it would submit trial data to global regulators soon.
The news comes as a panel of government advisors was preparing to meet Tuesday on the question of whether to authorize the Pfizer vaccine in kids aged 5-11, with top infectious disease expert Anthony Fauci predicting it would be available by mid-November.
We are encouraged by the immunogenicity and safety profile of mRNA-1273 in children aged 6 to under 12 years and are pleased that the study met its primary immunogenicity endpoints, Moderna chief executive Stephane Bancel said in a statement.
An interim analysis from a mid-to-late stage clinical trial of 4,753 children showed that two doses of vaccine produced a high level of neutralizing antibodies -- Y-shaped proteins that bind to the coronavirus and block it from entering human cells.
The vaccine was dosed at 50 micrograms, which is half of what is used among adults, but still produced on average 1.5 times as many antibodies in children as it did in young adults given the higher dose.
The majority of adverse events were mild or moderate, including fatigue, headache, fever, and injection site pain.
These early results, released via a press statement, do not yet include a vaccine efficacy estimate, which may be expected at a later time once cases have accrued.
- FDA meeting on Pfizer -
The Moderna news comes as the US Food and Drug Administration (FDA) is preparing to convene a panel of advisors to vote on whether to greenlight the Pfizer shot for younger children, paving the way for 28 million more Americans to be vaccinated.
A briefing document posted on the FDA's website indicated the agency believes benefits outweigh the most worrying side effect for this age group, namely myocarditis, or heart inflammation.
The overall analysis predicted that the numbers of clinically significant Covid-19-related outcomes prevented would clearly outweigh the numbers of vaccine-associated excess myocarditis cases, the document said.
But it acknowledged the benefit-risk calculus would differ when community transmission is very low, as was the case in the United States in June 2021.
The FDA also uploaded Pfizer's efficacy analysis, with the company estimating a two-dose course of its vaccine at 10 micrograms was more than 90 percent effective in preventing symptomatic disease.
Overall, more than 150 children aged 5 to 11 have died from Covid in the United States since the start of the pandemic, according to official data.
If all goes well, and we get the regulatory approval and the recommendation from the CDC, it's entirely possible, if not very likely, that vaccines will be available for children from 5 to 11 within the first week or two of November, Fauci told ABC News Sunday.