Hepatitis B vaccine: risks and benefits of universal neonatal vaccination.

Global eradication of hepatitis B, which has infected over 2000 million people worldwide, is an achievable goal. Hepatitis B vaccine is effective and safe, and is recommended in Australia as a four-dose childhood schedule commencing with a neonatal dose. A neonatal dose has a greater impact on carriage, the main reservoir of transmission, due to the inverse relationship of age and risk of chronic carriage. Universal vaccination is clearly cost-effective in countries of high hepatitis B endemicity but less so in countries of low endemicity. Other factors affecting the perceived benefits of universal vaccination in low-risk countries include the use of the preservative thiomersal in hepatitis B vaccines, and case reports of multiple sclerosis (MS) and unexplained fever in recipients. Careful epidemiological studies have failed to confirm any risk of MS or fever with the hepatitis B vaccine, which is now thiomersal-free. Other arguments against universal vaccination include 'unnecessary' vaccination of low-risk neonates. However, selective vaccination programmes targeting at-risk neonates are often poorly implemented and do not protect against horizontal transmission in early childhood. Universal vaccination, which is safe and effective, is the only practical means of achieving global eradication of hepatitis B.