Reviewed innate immunity, immunity boosters in the form of various vaccines esp mmr, bcg, opv etc. so called MDSC which are actually T suppressor/ regulatory/ T memory cells. Also the hypothesis of the microbiologist who published this. Find this atrocious and a viewpoint fanned by a paranoid researchers trying to actually shoot in the dark and making someone do a meaningless research to support this hypothesis.
Answer is a big No to MMR vaccine. Any viral infection or live viral vaccine would induce innate and adaptive immunity which is epitope specific and in turn some shared generic epitopes may offer a little cross protection to a variety of bugs. The said author not only talks of covid but also polymicrobial protection even sepsis. Immunity boosters are in fashion be it traditional medicines or repurposed drugs and vaccines. Cytokines storm is in fact a form of immune dysregulation and probably based on genetics that determine our T cells which are individual specific.