Newborns can be tested for hepatitis B at four months, but it is generally recommended that newborns be tested for hepatitis B at seven months. Newborns begin receiving the first dose of hepatitis B vaccine after birth, the second dose in the first month of life, and the third dose in the sixth month of life. At this point, the hepatitis B vaccine will be fully immunized. If a newborn is suspected of having hepatitis B, he or she can be tested for hepatitis B seven months after birth. In addition, newborns need to be well cared for during the time they are given the hepatitis B vaccine. Prevent the newborn from getting cold stimuli and inducing a cold, which can lead to a decrease in the effectiveness of the hepatitis B vaccine. Hepatitis B for newborns can be checked by drawing blood from a vein without fasting, and Hepatitis B V can be checked after eating or breastfeeding. If only the second of the Hepatitis B indicators is positive and the other results are negative, it means that the body has produced protective antibodies. If in doubt, consult a specialist for clarification.