Hepatitis B

Hepatitis B Overview

Hepatitis B is a viral infection of the liver that affects thousands in the U.S. each year. In 2023, there were 2,214 acute cases reported and an estimated 14,400 total infections after accounting for underreporting. In the same year, about 17,650 new chronic infections were diagnosed, resulting in about 1,769 deaths. The hepatitis B virus is spread through contact with infected blood and other body fluids, including from mother to baby during childbirth, contact with open cuts or sores, or even via household items contaminated with dried blood. Infants and young children are particularly vulnerable: roughly 90% of infants infected at birth develop chronic hepatitis B as do about 30% of children infected between ages 1–5. Without timely intervention, chronic infection can lead to liver damage, cirrhosis and increased risk of liver cancer or failure, with about 25% of those chronically infected suffering premature death due to liver complications.

Vaccination remains the most powerful defense: the hepatitis B vaccine, recommended at birth and completed with two subsequent doses, produces protective immunity in over 98% of infants and has driven a 99% decline in pediatric hepatitis B since its routine adoption in 1991. Administering the first dose within 24 hours of birth is essential to preventing mother-to-child transmission and lifelong liver disease.