They are self-reported by both Pfizer and Moderna, so it baffles me that doctors call it nonsense. It's also been observed in multiple independent studies, but I'll focus on Moderna and Pfizer since it came straight from their mouths.
Moderna self-reported auto-immune side effects in their study here:
https://www.nejm.org/doi/full/10.1056/NEJMoa2209367
They still concluded that the vax was safe and effective (despite a 36.8% efficacy which fails to meet the EUA-minimum 50%), stating that "adverse events were
mainly low-grade and transient, and
no new safety concerns were identified."
Weasel wording, btw. Yes, most side effects are usually low-grade and transient. But they reported side effects that were both high grade and permanent too. So, they didn't lie - but they also used selective wording to hide more serious maters. And how do they get around those serious matters? By saying no new safety concerns were identified. That's because their side effects were in line with those previously reported and Pfizer. FDA already approved EUA and distribution for a vax with a historic side effect profile, so there was precedent to ignore the side effects observed by Moderna. And this is why you can't just read summary paragraphs.
Speaking of Pfizer's previous reports...
Pfizer vaccine disclosures also listed autoimmune disorders as side effects.
Pfizer self-reported 1,050 vax-related autoimmune disorder side effects in their 3-month vaccine trial. This accounted for 2.5% of all side effects that Pfizer "highly correlated" to vaccine; the median report latency was < 24 hours after receiving the vaccine.
FDA knew this by the way, though they did not force vax manufacturers to include a single one of the 42,000 observed side effects in the vaccine disclosure documents when they distributed the vax. Did you ever see a list of side effects when you saw all of the "safe and effective" commercials? Nope. EUA drugs are not required to include side effect disclosures. That's why a commercial for blood pressure medicine will have a screen filled with fine print but the vax commercials did not.
In your doctor friends' defense, though, this Pfizer vax data was originally hidden to the public until March 2022 when a US District Court forced the FDA to release the data. Still, medical professionals have a responsibility to research this stuff before they definitively claim it to be nonsense; that is how misinformation is spread and how vaccine mandates cause undue harm on a population. In my experience, most practicing doctors do very little research and just follow public health guidance. This is dangerous when public health hid and misled medical communitie