[Torn]

> Now an international team, led by Flinders University, have found that in a small number of people, the immune system can accidentally confuse a normal adenovirus protein with a human blood protein termed platelet factor 4 (or PF4).

Seems to have been a legitimate, very rare, side effect

https://www.flinders.edu.au/research/articles/covid-vaccine-...

[tjohns]

It's worth clarifying that the adenovirus-based (viral vector) vaccines that article is discussing were a completely different technology from the mRNA vaccines.

[marcosdumay]

The mRNA vaccines also had a cloth problem (as in, it was extremely rare), that practically disappeared with a change on the application procedure.

[moralestapia]

Can you elaborate? What was the change?

[atomicnumber3]

I am quite curious too. I had heard that, despite arm vascular being very consistent among individuals, it does still vary. And I think for most vaccines I guess it doesn't matter if you hit something other than muscle. Maybe for the mRNA vaccines it does matter? I'm baselessly speculating though. Wish other person hadn't been so vague.

[Sammi]

Not 100% sure but I think it was this: Never inject into a vein. Always inject into a muscle.

[tsoukase]

In an intramuscular injection this is always tested by the nurse and this complication is far rarer than a nerve injury by the syringe. But in billions of cases anything can happen.

[marcosdumay]

Yes, they mandated a test to check if it was being injected into a vein.

[cogman10]

Pretty common test as well, pull the plunger back on the syringe if blood comes up you hit a vein.

A lot of drugs have this test, particularly drugs that should be injected in fat or muscle.