There is no strict standard for how late the second shot of hepatitis B should be given to newborns, and it is generally recommended to be given one month after birth. For newborns to receive hepatitis B vaccine is generally used 0, 1, 6 program, that is, the first vaccination when the baby was born, the second vaccination in the first month after birth, the third vaccination in the sixth month after birth. China is a big country of hepatitis B, the newborn vaccination is to better prevent hepatitis B infection, so it is very necessary to vaccinate on time, but if there are special reasons not to complete the vaccination can be delayed but the time is not strictly regulated. If there are special reasons for not receiving the hepatitis B vaccine on time, the vaccine should be given as early as possible when conditions permit.