Can flu shots lead to projectile vomiting?

Generally No: If this in fact a reaction, it is very rare and should resolve within 1-2 days. And it should occur within 24hrs of the shot. If the baby is vomiting projectily which means across the table, call your doctor.

No: Flu shots can sometimes result in viral symptoms which include nausea and vomiting. It is usually short lived and not too intense.