Vomiting is probably not due to vaccination. Newborn babies gains weight 25-30 gram per day and your baby gains weight 1600 grams within1 and half months that means 32-35 grams per day this is normal. Vomiting after feed in newborn babies is called as regurgitation it is very small in quantity and generally it is considered as normal if there is appropriate weight gain. Burping is most important after feeding, you can consult your pediatrician if you feel that regurgitation this is more frequent and large quantity.