令和３年８月 17 日

ワクチン接種後も感染予防対策を！
金沢大学長 山崎光悦
学生の皆さん
本学では、新型コロナワクチンの大学拠点接種（職域接種）を７月６日から開始し、本学の学生・教職員の接種希望者を対象としたワクチン接種が順調に進み、１回目接種は無事に終えて、現在は２回目接種を順次行っており『学生全体の接種率は、自治体等での接種も含めると 88％』に達しています。
このように高い接種率となったのは、皆さんが、ワクチン接種に関する正しい知識に基づき、判断された結果であり、嬉しく思います。
全国では、２回目のワクチン接種を完了した人の割合は 36.5％になり、65 歳以上の高齢者では83.4％に達しました（８月 13 日 首相官邸公表）。２回のワクチン接種による発症や重症化の予防効果は明らかで、最近は 65 歳以上の感染者は全体の数％に減っており、また重症者の数も増えていません。高齢者に対するワクチン接種が感染及び感染後の重症化を共に抑えているものと理解されています。今では新たな感染者として最も多いのは 20 歳代の方で、19 歳以下の方がそれに続きます（※1：日本感染症学会、日本環境感染学会）。
しかしながら、２回のワクチン接種を済ませても感染することがあります。国立感染症研究所から、ワクチン接種後に新型コロナウイルス感染症と診断された人の調査結果が報告されました。それによると、２回のワクチン接種後でも僅かではあるが感染は起こり得ること（ただし、重症化の可能性は低いとされています)、他の人に感染を広げる可能性があることが示されています（※2：国立感染症研究所）。具体例として、福岡市では６月 30 日～８月６日に同市が確認した新規陽性者 4,173 人のうち、２回接種後に十分な免疫がつくとされる２週間以上経過して感染した人は 70 人で、全体の約 1.7％だったと報告されています（※3：西日本新聞）。
また、最近では、変異した感染力・増殖力の強い新たなウイルスのデルタ株がそれまで流行していたウイルスに置き換わっています。米国疾病対策センター（CDC）によると、デルタ株は１人の感染者から８～９人に感染させる威力があるとのことです。インフルエンザは１～３人、従来型の新型コロナは2.5 人なので、その感染力はかなり強力であるといえます。
新型コロナウイルス感染症に感染するのを予防するためには、一人でも多くの国民がワクチンを接種することが必要です。しかし、中には体質や基礎疾患のためにどうしてもワクチンを接種できない人もいます。ワクチン接種を希望しても受けることができない人を周囲の人が接種することにより守るのが「集団免疫」の本来の考え方です。これにより社会全体が守られることになります。
最近、新型コロナウイルス感染症に感染した人の多くは感染の原因（経路）が不明です。会食で感染する人は今もいますが、その多くは親しい友人と少人数で会食した方です。こうしたちょっとした会食でも感染してしまうのがデルタ株といえます。引き続き不要不急の外出は控え、これまで以上に自身や周りの人たちへの感染リスクが高まる行動を慎むことが重要です。ワクチン接種を２回済ませていたとしても、基本的な感染防止対策を継続してください。
本学では、ワクチン接種を８月末までに完了する予定です。学生一人一人が感染予防対策を講じることにより、10 月からの第３クォーターの対面授業を安全に再開でき、以前のような日常の学生生活に近づくことができるものと期待します。引き続き、皆さんのご理解とご協力をよろしくお願いします。
※1 https://www.kansensho.or.jp/uploads/files/topics/2019ncov/covid19_tameni_210806.pdf※2 https://www.niid.go.jp/niid/ja/diseases/ka/corona-virus/2019-ncov/2488-idsc/iasr-news/10534-498p01.html※3 https://www.nishinippon.co.jp/item/n/783870/

August 17, 2021
Keep taking measures to prevent infection even after vaccination!

YAMAZAKI Koetsu
President, Kanazawa University

Dear Students,

The workplace vaccination against COVID-19 at Kanazawa University started on July 6.
The vaccination for applicants among our students, faculty and staff is making good progress.
We have completed the first dose safely and are providing the second dose in order. “The rateof all the students who got vaccinated has reached 88% including those vaccinated by localgovernments”. I am happy to see such a high vaccination coverage resulting from everyone's
decision based on correct knowledge about vaccinations.
In Japan, the percentage of people who have received the second dose of vaccination
has reached 36.5%, and 83.4% among the elderly aged 65 and over (as announced by thePrime Minister's Office of Japan on August 13). Receiving the vaccine twice obviously provides
preventive effect on appearance of symptoms and severity of the disease. The number of
infected people over 65 years old has recently decreased to a few percent of the total, and thenumber of severe cases has not increased. It is understood that vaccination for the elderly
prevents both infection and the severity of the disease even after infection. Nowadays, thelargest number of newly infected people are in their 20s, followed by those under 19. (*1: TheJapanese Association for Infectious Diseases and the Japanese Society for Infection
Prevention and Control).
However, even after getting vaccinated twice, people can still become infected. The
National Institute of Infectious Diseases reported the results of a survey of people who werediagnosed with novel coronavirus infection after vaccination. According to the report, even after
having two doses of the vaccine, a small number of infection can still occur (but the possibilityof serious illness is considered low), and there is a possibility of spreading the infection to otherpeople (*2: National Institute of Infectious Diseases). As a concrete example, it was reported
that in Fukuoka City, of the 4,173 new positive cases confirmed by the city between June 30
and August 6, 70 people, that is about 1.7% of the total, had been immunized after more than
two weeks since they had the second doses of vaccination (*3: Nishinippon Shimbun).
In addition, recently, delta variant of new viruses with mutated infectious and proliferative
potential have replaced the previously spreaded type. According to the CDC (Centers forDisease Control and Prevention), the delta variant is capable of infecting eight to nine people
from one infected person. As it is one to three people for the flu and 2.5 people for theconventional novel coronavirus, the delta variant has quite stronger infectiosity.
In order to prevent people from COVID-19, it is required that as many people aspossible are vaccinated. However, there are some people who cannot be vaccinated due totheir constitution or underlying diseases. The original idea of "herd immunity" is to protect those
who cannot be vaccinated by having those around them vaccinated. In this way, the entire
society is protected.
The cause (route) of infection is unknown for many people who have recently been
infected with the novel coronavirus infection. There are still some people who get infected atdinners, but most of them are those who had dinner with the limited number of their closefriends. It can be said that the delta variant can be transmitted even at such a table. It is
important that we continue to refrain from going out unnecessarily and avoid activities that
increase the risk of infection to ourselves and others. Even if you have received two doses ofvaccination, please continue to take basic infection prevention measures.
Kanazawa University plans to complete vaccinations by the end of August. We expectthat by each student taking infection prevention measures, we will be able to safely resume thethird quarter of face-to-face classes from October and get closer to the daily student life asbefore. I would appreciate your continued understanding and cooperation.
*1 https://www.kansensho.or.jp/uploads/files/topics/2019ncov/covid19_tameni_210806.pdf (Japanese only)*2 https://www.niid.go.jp/niid/ja/diseases/ka/corona-virus/2019-ncov/2488-idsc/iasr-news/10534-498p01.html(Japanese only)*3 https://www.nishinippon.co.jp/item/n/783870/ (Japanese only)