By 2 month old baby not taking milk either formula nor breastfeed after 45 days vaccine what shall I do

A. no formula not given. Breastfeeding is the best source of natural immunity and antibodies to a newborn baby never give formula milk as it is not required at all exclusive breastfeeding is a must for good immunity and baby health , reduces colic and gas issues and overall brain development of the baby. No water , ghutti or any other syp is given till 6 months of age .