https://en.wikipedia.org/wiki/Angiotensin-converting_enzyme_...
What's happening now has more to do with their theocratic regime that didn't take the threat seriously and doesn't care much about their people.
That doesn't sound unreasonable at all when the two outbreaks are separated by a century. A lot has changed between 1920 and 2020.
Iran is a theocratic authoritarian regime under extreme international sanctions. Might have something to do with that. Iran also only has 0.2 hospital beds per 1k people.
https://www.cia.gov/library/publications/the-world-factbook/...
The Europeans cannot enforce the JCPOA without either some kind of American cooperation or a major decoupling their financial systems from the US. I believe Macron has made public musing about the latter as an option, but then again Macron says a lot of things that lack pan-european support.
“The World Health Organization estimates that 2–3% of those who were infected died (case-fatality ratio).
[...]
In Iran, the mortality was very high: according to an estimate, between 902,400 and 2,431,000, or 8% to 22% of the total population died.” — source, Wikipedia, see [0].
I wonder if it’s genetics (immune system reacts differently?), or cultural (habits - kissing on cheeks, handshaking, large religious or non-religious gatherings) or climate, or a mix.
References: [0]: https://en.wikipedia.org/wiki/Spanish_flu
Edit: admittedly, it’s too early to draw conclusions. It’ll take a few weeks to have more realistic numbers.