Source: Infectious disease epidemiologist who has been interested in phage research for two decades ;)

But you will find on that same Wikipedia page an entry for d'Herelle, and if you follow that...as you note yourself, you get an animal trial in 1919 as well as a human trial. D'Herelle then heads to Indochina to work on Cholera, and he's awarded an honorary doctorate two years after the USSR is founded - along with one of the field's most prestigious medals.

---

Is that a tight timeline? Yes. But the idea that "The West" ignored phages because it was some sort of Soviet pseudoscience is contrary to the historical record.

The west abandoned phage therapy because unfiltered endotoxins made phage therapy dangerous, and until the modern era, antibiotics are pretty superior in nearly every respect.