This is a good summary paper with some safety concerns: https://www.nature.com/articles/nrd.2017.243.pdf?origin=ppub https://www.nature.com/articles/nrd.2017.24

This is a good summary paper with some safety concerns: https://www.nature.com/articles/nrd.2017.243.pdf?origin=ppub https://www.nature.com/articles/nrd.2017.243.pdf?origin=ppub > A possible concern could be that some mRNA-based vaccine platforms 54,166 induce potent type I interferon responses, which have been associated not only with inflammation but also potentially with autoimmunity 167,168 . Thus, identification of individuals at an increased risk of autoimmune reactions before mRNA vaccination may allow reasonable precautions to be taken. Another potential safety issue could derive from the presence of extracellular RNA during mRNA vaccination. Extracellular naked RNA has been shown to increase the permeability of tightly packed endothelial cells and may thus contribute to oedema 169. Another study showed that extracellular RNA promoted blood coagulation and pathological thrombus formation 170. Safety will therefore need continued evaluation as different mRNA modalities and delivery systems are utilized for the first time in humans and are tested in larger patient populations.