Chronic hepatitis B infections among U.S. children could rise 83% over 20 years if the newborn vaccine dose shifts from a routine shot to a decision parents make with their doctor, according to a computer model published in Annals of Internal Medicine. The figure is a projection based on stated assumptions, not a count of actual infections. Researchers at Massachusetts General Hospital and Harvard Medical School built the model.
The team followed a hypothetical group of 3.6 million babies born in the U.S. in 2026 through age 20, ABC News reported. Delaying the first dose until 2 months raised projected chronic infections by 19%. A shared decision-making approach raised them by 83% and left about 1.8 million young adults unprotected at age 20, compared with about 474,000 under a delayed dose and about 232,000 under a universal birth dose.
