I always used to get coughs and colds that would linger. My missus meanwhile would shrug the same lurgy off within a day or so.
I was therefore concerned as to how tecfidera might make this situation worse for me. but it hasn’t. not at all. in fact, i seem to resolve colds more quickly than my better half does these days.
the conclusion, tecfidera provides little impact in such things (for me at least) whilst my healthier diet since diagnosis (fresh fruit, veg, juice, no cow products, minimal fat and eggs etc) seems to have bolstered my immunity to seasonal ailments.
i think you might be suffering some bad luck / could improve the quality of what you eat and drink / probably have kid(s).