A modelling study warns that ending the hepatitis B shot for all US newborns could sharply increase chronic infections.

Led by Amir Mohareb of Massachusetts General Hospital, it modelled about 3.6 million infants born in one year.

Hepatitis B is highly contagious and can lead to cirrhosis, liver failure and liver cancer.

For decades, US doctors have given the first dose to all babies within 24 hours of birth.

Advisers chosen by Robert F. Kennedy Jr recommended parents decide on the shot if the mother tests negative.

In March, a federal judge temporarily blocked those changes, restoring the universal birth dose. The lawsuit continues.

With 75% of infants getting a delayed dose, lifetime chronic infections would rise about 19%. At 50%, they would rise 83%.

In a worst case of 26% uptake, chronic infections would surge by 225%, the researchers found.

Read the full article for more details on the hepatitis B vaccine study.