Yes, the most likely explanation is a shared environmental exposure, such as a toxin or a shared deficiency (eg Vitamin D deficiency in the winter)
I think part of the story is that the same exact symptoms get diagnosed as a different disease depending on what's in the news and what vaccinations the unwell person got. Virtually all the respiratory illnesses that would normally be attributed to influenza were instead attributed to coronavirus.
See, that's where this gets a little aggravating for me. Every time I try and poke the bear of virology (or immunology, for that matter), someone goes full retard on coronavirus. I'd rather just ignore that, and really look at the state of virology research/knowledge up to Ebola or SARS. I'd want to focus on influenza, perhaps. Or some other illness that has been (mis)characterized as a virus, but has been around for at least several decades. Maybe chicken pox. Which was then also shingles, and now monkey pox. But again, focus on it as chicken pox, and tell me what caused symptoms to seemingly pass from one child to the next.
I could be going at this too hard, but are there even any truly communicable diseases, aside from brain rot and stupidity?
I'm skeptical of whether contagion exists
One interesting point of comparison is hydrophobia and puppy pregnancy syndrome
