paulfromcamden
Baffled
Metro News. I'm not familiar with that scientific journal.
Joe
The Japan Times article it cites is a bit more detailed/nuanced:
https://www.japantimes.co.jp/news/2021/11/18/national/delta-variant-self-destruction-theory/
The end of the piece states that researcher Ituro Inoue plans to publish a paper on this soon.