Asked my MS nurse when I was first diagnosed as my GP was concerned. I was on Avonex at the time (awful useless drug) MS nurse said go ahead and it’s important we get them as getting flu could trigger relapse. I’d rather have a few days feeling crap after it than get 🤧 flu . I did feel crap at least 2 days a week like I had flu with interferon /Avonex anyway.
Also plegridy is an interferon group of drugs (least effective) and mavenclad is the name for cladribine (a highly effective drug) @itsmewithms