A lot of people are wondering why #Japan has so few cases of #COVID19. In this commentary, @NathanGrubaugh and I speculate on some possible reasons. (1/n)

https://www.embopress.org/doi/10.15252/emmm.202012481

An important observation made by @NathanGrubaugh is the recent introduction of #SARSCoV2. Note the earlier infections came from China, while ones in March are predominantly from Europe (plus Egypt, USA). Japan has now tightened travel bans. (2/n)

https://nextstrain.org/ncov/global?f_country=Japan

An intriguing link is the correlation between the #BCG vaccination and #COVID19. In countries that mandate childhood BCG vaccines, cases of #COVID19 and deaths appear to be low. For more discussions see
(3/n)

https://www.jsatonotes.com/2020/03/if-i-were-north-americaneuropeanaustral.html
https://news.yahoo.co.jp/byline/kimuramasato/20200405-00171556/ (by Prof. Miyasaka)

We are grateful for Dr. Hiroshi Iwasaki (my father who is a guru on internet searches) for collecting information from Japanese media, and @HironoriFunabi1 for his informative tweets on this issue (end)