Does anyone know what happened to psychoneuroimmunology, and why we don't hear so much about it these days?

There is an active research center for psychoneuroimmunology where I work. I don’t think it has gone anywhere. If you look at the pubmed timeline, it seems to have been well-studied in the 1940s-1950s, with a larger resurgence in recent years:

https://pubmed.ncbi.nlm.nih.gov/?term=psychoneuroimmunology&sort=date

Not be snarky, but I never heard of psychoneuroimmunology before, so I didn’t notice we aren’t hearing so much about it these days.

The survey of med pubs from @nikipedia suggest it’s along the lines of mind-over-matter and placebo effects. Are those being researched less than they used to, or does the term mean something more specific?