Intro
The hepatitis B birth dose is a public-health “seatbelt”: most people never need it — until they do.
It exists because hepatitis B acquired at birth can silently become lifelong disease.
Key Points
- Early hepatitis B infection is much more likely to become chronic than adult infection
- Chronic hepatitis B increases lifetime risk of severe liver disease
- Screening and follow-up help, but they can fail
- The birth dose provides early protection and redundancy
Background
Hepatitis B is a liver infection. Many adults clear it. Infants often don’t.
The birth-dose strategy is designed to stop infection before it becomes lifelong.
Why the birth dose was introduced
Before routine vaccination, perinatal transmission was a major pathway into chronic infection.
A universal birth dose was introduced in many settings because risk-based approaches miss edge cases.
The “why” in one box
Why early hepatitis B prevention is different
When screening isn’t enough
Even good systems have failure modes:
- late/no prenatal care
- test or documentation errors
- unexpected deliveries
- follow-up gaps
A universal birth dose is designed for reality, not perfection.
FAQ
Q: Is the birth dose still recommended globally?
A: In many countries and in WHO guidance, yes — especially where prevalence is higher or system gaps exist.
Q: Does delaying the first dose change the rest of the schedule?
A: It can, depending on national schedules. The key issue is the “unprotected window.”