Direct quote from the EMA EPAR EMEA/H/C/005791 Revision 29: SPIKEVAX (COVID-19 mRNA vaccine [nucleoside modified]), 19-Sep-2022
“The applicant provided a preliminary risk evaluation regarding potential nitrosamine contaminations in the finished product, which is considered acceptable but should be complemented with a quantitative risk assessment, especially focusing on nanoparticle constituents. (REC)”