In Turkey, there are three vaccines that have been included in the vaccination process, that is, approved. These are CoronaVac developed by China’s Sinovac company, Russian production Sputnik V and Pfizer/BioNTech. The vaccine developed by BioNTech differs from traditional vaccines due to the new technology used. The BioNTech vaccine uses technology known as mRNA (messenger RNA or messenger RNA). On the other hand, those who come to the vaccine queue are undecided in the choice of angle and wonder about the side effects of vaccines. So, what are the side effects of mRNA vaccines (Biontech, Moderna)?