Why give newborns a hep b vaccine?

Hepatitis B vaccine: Hep b vaccine helps prevent liver infection (hepatitis) from the hepatitis b virus which can induce severe disease that can be fatal. Vaccinating newborns with hep b is most useful in situations where a pregnant mom has the disease but has not had prenatal testing for it and also moms who have tested positive but have no acute disease.

Prevention: Hep b vaccine is used to prevent one from getting hepatitis b liver infection. By proctecting from infection you also are decreasing the possibility of liver cancer in later life which often happens as a result of infection.

Recommendations: Even though hep b vaccine can be started at any age as the infant is not exposed to hep b virus in infancy, but like other vaccines recommended to be given are based on the recommendation of cdc and american academy of pediatrics the reason the first dose is given in the hospital after birth is to make you aware that baby needs to continue with 2nd and 3rd dose and other childhood vaccines.