Why do babies need the hepatitis B vaccine?

Hepatitis B is a virus that can damage the liver and lead to lifelong health problems. The hepatitis B vaccine prevents short-term illness (acute hepatitis) and a life-threatening infection called chronic hepatitis B. The American Academy of Pediatrics believes that a federal advisory panel's decision to weaken hepatitis B vaccine recommendations for newborns is dangerous and could put children at risk. AAP still strongly recommends that all babies get a first dose of hepatitis B vaccine within 24 hours of birth as part of routine care.

Newborns need the hepatitis B vaccine soon after birth. That's because they could be unknowingly exposed to the virus during labor or shortly after coming home. Other family members or caregivers can give hepatitis B to newborns as people often don’t know they are infected with the virus due to lack of symptoms.

Children infected at birth and in early childhood are much more likely to get chronic hepatitis B than adults. The majority (90%) of infants infected at birth develop chronic hepatitis. That's why babies benefit most when they get the vaccine early, during the first 24 hours of life. Hepatitis B spreads when blood or other body fluids with the virus get into the body of someone who isn't infected. The virus can survive for up to 7 days in dried blood particles on surfaces and objects, including personal items people use regularly and sometimes share.

People can become infected with hep B through contact with blood or other bodily fluids from an infected person, including during birth or by sharing items like razors or toothbrushes, through sexual activity, or from accidental pokes by sharp objects like needles. People with chronic hepatitis often do not have symptoms, but the effects are serious. The disease can cause liver damage, liver cancer and death.

The good news is that most people who get vaccinated against hepatitis B are immune for life. The vaccine is over 95% effective at preventing this disease in children and adults. Babies have incredible immune systems, ready to learn as soon as they are born. The vaccine, given in the first 24 hours of life, teaches their immune system how to recognize and resist the virus faster than the virus can multiply and cause disease.

The first dose of the hepatitis B vaccine protects newborns from possible exposures during delivery and the first few days of life. It provides a safety net for babies whose family members may not know they are infected. Testing for hepatitis B during pregnancy or delivery can be helpful, but sometimes results aren’t ready in time or the test may miss an infection. Mothers always have the chance to get infected between the time they’re tested and they give birth.

People are tested for hepatitis B during each pregnancy. Testing may be done during labor and delivery at the hospital. Hepatitis B vaccine can be given to someone during pregnancy if they have not been vaccinated. Sadly, 25% of babies who get chronic hepatitis B die. In high-risk deliveries, the baby may receive a dose of hepatitis B immune globulin in addition to vaccine. This gives the immune system extra antibodies that protect the baby for a few weeks post-birth.

Babies get a second dose of hepatitis B vaccine when they are 1 month to 2 months old and the third dose when they are 6 months to 18 months old. After babies complete all their doses, they live a life free from hepatitis B and the liver damage it causes.

Hepatitis B vaccine can be combined safely with other vaccines in the same shot. It can also be one of several shots for different vaccines received in the same visit to the doctor. If you're an expecting parent with questions about the vaccine, talk with your OB/GYN and pediatrician before your baby is born. Tell your doctor if someone getting the hepatitis B vaccine has any life-threatening allergies. Do the same if you are sick. People with minor illnesses, like a cold, can get vaccinated. You and your doctor will evaluate your situation. You can discuss testing and preventing hepatitis B through vaccination.

Occasionally, people have redness or swelling or feel soreness where they received the shot. A few babies might get a fever. For any signs that concern you, call your doctor.