Officials and media pundits pointed to the 'nefarious Russians' or their allies, despite the entire story being hotly disputed among scientists.

But this week NBC - which it should be recalled was a leading outlet pushing the Havana Syndrome narrative in the first place - has this to report: "In a new intelligence assessment, the CIA has ruled out that the mysterious symptoms known as Havana Syndrome are the result of a sustained global campaign by a hostile power aimed at hundreds of U.S. diplomats and spies, six people briefed on the matter told NBC News." 

Out of literally hundreds of alleged instances, some which were claimed to have happened in the streets of D.C., the CIA says it only considers "about two dozen cases" instances where they "cannot rule out foreign involvement". 

The NBC report spells out, "But in hundreds of other cases of possible symptoms, the agency has found plausible alternative explanations, the sources said."