12.5 month old received mmr 9 days ago. now has large swollen glands behind ears on both sides. normal? pamphlet said 2-3 weeks later possible mild mumps illness but hasnt been that long yet.

Unlikely mumps: There are 4 possibilities.This could be an unrelated likely viral illness triggering the glands to swell. It could also be a mild reaction to one of the 3 weakened viruses that are in that vaccine. I like the 2nd option as I find one of the measles viruses can trigger symptoms about 10 days out. If it is the vaccine I consider it good evidence that it will work as hoped. The symptoms should pass