What is Hepatitis B (Hep B)?
Hepatitis B (Hep B) is a viral infection that causes swelling in the liver.
Some people infected with Hep B experience a short-term illness, also called acute Hep B. Symptoms include fever, fatigue, loss of appetite, nausea, jaundice, and pain in the muscles, joints, and stomach.
Acute Hep B can lead to chronic Hep B, a long-term illness that can cause liver damage, liver cancer, liver failure, and death. 90% of newborns and babies infected with Hep B will develop chronic Hep B. Chronic Hep B is fully preventable through vaccination, which infants can receive at birth.
A person with active or chronic Hep B can pass the infection to another person, including infants, through blood and other bodily fluids. Infants can contract Hep B during birth if the parent giving birth has Hep B.
A person may also contract Hep B if they share razors, toothbrushes, and needles with a person who has Hep B, if they come into contact with the blood of a person who has Hep B, or if they have sex with someone who has Hep B.
While most people with chronic Hep B do not have symptoms, they can still spread the disease to others. Between 850,000 and 2.2 million people in the United States are living with chronic Hep B.
Protecting Yourself and Your Child from Hep B and Liver Cancers Caused by Hep B
You can prevent Hep B infection and its most serious potential effects, like cancer, by getting yourself and your child vaccinated. Most people who receive the Hep B vaccine are immune for life.
The Hep B vaccine is available to anyone ages 59 or younger, as well as to people ages 60 and older who are at an increased risk of Hep B exposure and were not vaccinated previously.
Infants, babies, and children who contract Hep B are 80-85% more likely to experiencechronic Hep B and its severe symptoms than adults who contract Hep B. Early vaccination is an essential step for lifelong liver health.
The American Academy of Pediatrics recommends that all infants receive their first dose of the Hep B vaccine at birth. The birth dose is an essential part of preventing long-term Hep B illness in infants. Babies can then complete the vaccine series by getting the second dose of the Hep B vaccine at one to two months old and the third dose at six to 18 months old. Most people do not need a booster dose of the Hep B vaccine later in life. All infants, regardless of their parent’s Hep B status, should get the birth dose of the Hep B vaccine and two additional doses by 18 months old.
Note: In December 2025, the U.S. Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) recommended that parents who test negative for Hep B engage in individual-based decision-making with a healthcare professional before their baby receives the birth dose of the Hep B vaccine. Individual-based decision-making is a conversation between a parent or patient and healthcare professional to help inform treatment plans. An individual-based decision-making recommendation does not impact your ability to access the birth dose for your baby. If you have insurance, an individual-based decision-making recommendation also shouldn’t impact coverage of your vaccine.
Additionally, ACIP now recommends that parents ask their healthcare professionals about getting their child an antibody blood test before they receive the second and/or third doses of the Hep B vaccine. However, these tests cannot reliably report whether a child has long-term protection against Hep B after one dose of the vaccine. These tests also require additional infant blood draws and potentially higher costs for families, without a guarantee that they will provide useful information.
Many public health experts have expressed concerns that this ACIP recommendation, which lacks evidence, will unnecessarily delay or otherwise hinder access to the Hep B vaccine for some infants, which could put them at higher risk of infection and the lifelong impacts of such infection. This resource recommends following the AAP’s recommendations because they are accurate, scientifically rigorous, and timely.
Additional Facts About the Hep B Vaccine
Getting the Hep B vaccine at a very early age provides effective, lifelong protection against liver damage, liver failure, and liver cancer.
- The Hep B vaccine prevents serious illness from all types of transmission. Hep B is often thought of as a sexually transmitted disease, but it is also transmitted in other ways, such as from a parent giving birth to their newborn. The risks of Hep B infection in an infant are much higher than the risks of Hep B infection in an adult. This is why the American Academy of Pediatrics recommends that infants receive their first round of the Hep B vaccine within 24 hours of birth and two additional doses by 18 months old to complete the 3-dose vaccine series. Often, people don’t know they have Hep B because they don’t have symptoms. Even without symptoms, Hep B can be transmitted and result in liver damage, liver failure, liver cancer, and death.
- The Hep B vaccine is 90-95% effective at preventing chronic Hep B infection. Like all vaccines, the Hep B vaccine is continuously monitored by government agencies and non-government health experts through various reporting systems, safety assessments, and collaboration.
- The Hep B birth dose is administered in countries across the globe. Amongthe World Health Organization’s 194 member states, 115 have adopted itsrecommendation to give infants a dose of the Hep B vaccine at birth. Some countries suggest delaying the first dose of the Hep B vaccine for babies whose parent tests negative for Hep B, but those countries often have alternative prevention tools that the United States lacks, such as universal Hep B screening and testing for pregnant people.
- The Hep B vaccine does not cause autism. Getting the Hep B vaccine may cause mild symptoms, including soreness and swelling at the site where the shot was given. However, studies have repeatedly found no link between autism and vaccines like the Hep B vaccine or the vaccine preservativethimerosal.
Hep B Vaccine Next Steps
Discuss any questions you have about Hep B and the Hep B vaccine with a healthcare provider. If your child hasn’t yet received the Hep B vaccine or did not complete the full vaccine series by 18 months old, consider scheduling an appointment with a healthcare provider to discuss next steps.
