my baby is 16 months old. he was cooing well and having conversations with us very well till Las week. monday he had vaccine. since then he has become very cranky. it been 4 days now still he's very cranky, cried alot while falling asleep, also aftr waking up plays for a while and then starts to cry. has completely stopped cooing. now smile n squels Lot. eye contact has reduced alot. no conversation wit us. wenevr he sees us he smiles n squils. what can be the reason for these changes? is this normal? just a phase? o something to worry? he moves in direction of sound and tracks objects well. bt avoids conversations n don hold much eye contact. hence I'm worried. since las week he was very normal