Time to Develop Immunity After First Hepatitis B Vaccination
After the first dose of hepatitis B vaccine, approximately 30-55% of healthy adults under age 40 develop protective antibody levels (anti-HBs ≥10 mIU/mL), which typically occurs within 1-2 months after that initial dose. 1
Timeline of Immune Response
The development of protective immunity follows a predictable pattern after the first dose:
- After dose 1 (at 1-2 months): 30-55% of healthy adults aged <40 years achieve protective antibody levels 1, 2
- After dose 2 (at 2-3 months from start): Approximately 75% achieve protection 1
- After dose 3 (at 7-8 months from start): >90% of healthy adults aged <40 years achieve protection 1
Among healthy infants, the response is somewhat different, with 25% achieving protective levels after the first dose and 63% after the second dose 1
Critical Factors Affecting First-Dose Response
Age is the most important determinant of vaccine response. After age 40, response rates decline, and by age 60, only approximately 75% of vaccinated persons develop protective antibody levels even after the complete 3-dose series 1, 2
Other factors that reduce first-dose response include:
Clinical Implications for Protection
A single dose provides inadequate protection for most individuals. While 30-55% may develop measurable antibodies after one dose, the complete 3-dose series is essential for optimal and durable immunity 1
The standard vaccination schedule (0,1, and 6 months) is designed to maximize both the proportion of responders and the durability of protection, with the third dose acting primarily as a booster to provide optimal long-term immunity 1
Accelerated Schedules for Rapid Protection
For situations requiring faster immunity development, accelerated schedules can achieve earlier seroprotection:
- 3-week schedule: 70% seroprotection by 1 month after the third dose 4, 5
- Standard accelerated (0,1,2 months): Similar early protection with a 12-month booster 2, 6
However, these accelerated schedules still require multiple doses, and a single dose remains insufficient for reliable protection 4, 7, 5
Common Pitfalls to Avoid
- Do not assume a single dose provides adequate protection for most patients, even if antibody testing shows a response—complete the full series 1
- Do not delay subsequent doses unnecessarily, as this prolongs the period of incomplete protection, though longer intervals between doses do not reduce final immunogenicity 1
- Recognize that older adults (>40 years) have significantly lower response rates even after the first dose and may require revaccination or alternative strategies 1, 2