This peak in the late 80's to early 90's coincides with the use of a particular vaccine given to children in the 1960's. Can't remember which vaccine it was though. Anyone know?
Experimental vaccines are MUCH older. They were tested in hospitals. Epidemics tended to occur in hospitals. There is no way to be sure there is not a link at this time.
Don't take this as accurate, my memory is fubar, but I think an early experimental vaccine was being tested at the site of the 1934 Los Angeles epidemic. Those who got sick, and they did, were awarded massive compensation. Last time I went looking for the online evidence of this, to confirm it, I could not find it. Previously it was available. This was circa 1931.