no the flu vaccine will not cause permanent (or any) behavioral changes but the age is significant. at age 14-15 months is really the beginning of a period often termed as the "terrible twos". it starts in the child's second year (like now) not the second birthday. some of my most challenging examinations are in children of this age. this is a period that can be hallmarked by interesting tantrums misbehavior stranger anxiety (even with people they know) and assertion of their independence. a very challenging time so take a deep breath. be patient but consistent with your discipline. it will all be over in a year or so.
can the flu booster cause permanent behavior change in babies (14 months old)?