Vaccinations are the most effective defense against hepatitis and people should take booster injections in order to maintain immunity, local medical experts said on Tuesday, which also marks World Hepatitis Day.

Viral hepatitis, tuberculosis and AIDS are the world's major infectious diseases. There are about 2 billion people infected with hepatitis B; and between 500,000 and 700,000 people are killed by liver failure, liver cirrhosis and liver cancer due to hepatitis B infection annually.

Hepatitis is preventable and treatable but most people don’t have much awareness of the disease.

“The effects of vaccination can wear off over time,” said Dr Chen Demei from Shanghai Ren'ai Hospital. “Currently, Chinese children receive hepatitis B vaccinations at birth. But the protection is not lifelong. There are also differences between people. Some people can have a high level of antibodies for the long time, while others have a low level and protection remains short.”

“It's necessary to receive a blood test to check antibody levels and receive another round of vaccinations if the level is low or has vanished,” she added.

Dr Chen Demei from Shanghai Ren'ai Hospital checks a patient's blood test report for hepatitis B antibodies.

A nurse injects a hepatitis B vaccine into a patient's arm.