In plain words
Hepatitis B is a viral infection of the liver. It can be acute (short and severe) or chronic (long term). Chronic infection puts people at high risk of death from cirrhosis and liver cancer.
It can be prevented with a safe, effective vaccine.
Key facts
- WHO estimated 240 million people lived with chronic hepatitis B in 2024, with 0.9 million new infections a year.
- In 2024 it caused an estimated 1.1 million deaths, mostly from cirrhosis and primary liver cancer.
- The vaccine is usually given soon after birth with boosters weeks later and gives nearly 100% protection.
- Infection in adulthood becomes chronic in less than 5% of cases, versus about 95% for infection in infancy and early childhood. This is why infant vaccination is prioritised.
How it spreads
From mother to child at birth, in early childhood through contact with open cuts and sores, and through blood or body fluids: unsafe injections, needlestick injury, tattooing, piercing, sharing contaminated needles, and sex with an infected partner.
Symptoms
Most people have no symptoms when newly infected. Some have an acute illness lasting several weeks, including yellowing of the skin and eyes (jaundice).
Where the burden is
Highest in the WHO Western Pacific Region (102 million chronically infected) and African Region (64 million). Chronic infection in children under 5 fell to just under 1% in 2019, from about 5% before vaccination.
Sources
- WHO fact sheet, Hepatitis B, published 28 July 2026, read 9 October 2026.
Last reviewed: 9 October 2026. Reviewer: none yet. This page is general education and is not medical advice. Figures are WHO's and may have been updated since.