https://www.nejm.org/doi/full/10.1056/NEJMc2101667https://www.mhlw.go.jp/content/10900000/001132657.pdfhttps://www.bundesgesundheitsministerium.de/en/coronavirus/faq-covid-19-vaccination.htmlhttps://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html
http://www.nicovideo.jp/watch/sm42616844
