Timing of primary three-dose hepatitis B vaccination and postvaccination serologic testing among a large cohort of healthy adults.

This study evaluated the optimal timing of a primary three-dose hepatitis B vaccination and postvaccination serologic testing (PVST) among a large group of healthy naïve adults in the Netherlands. Data were collected from the Ease Travel Clinic hepatitis B vaccination database. The study population consisted of 22,997 adults who received three hepatitis B vaccinations. Seroprotection was attained in 97.3% individuals. When compared with PVST performed at 1-2 months (98.2%) after the final dose, lower seroprotection rates were observed with <1 (97.3%, p = 0.128), 3-6 (90.6%, p < 0.001), and ≥7 (88.4%, p < 0.001) months after vaccination. Among the subpopulation with a PVST 1-2 months, no statistically significant difference was observed for the various intervals between the first and second vaccination (<1, 1-2, 3-4, or ≥5 months). When compared with 4-5 months between the second and third vaccine dose, lower seroprotection rates were observed with <4 (odds ratio [OR]: 0.29, p = 0.020) and ≥12 (OR: 0.22, p < 0.001) months, although comparable rates were observed with 6-11 months interval (OR: 0.85, p = 0.262). Our data indicate that PVST should be obtained 1-2 months after the last vaccination and a delayed PVST was the major determinant of a lower seroprotection rate after primary three-dose hepatitis B vaccination schedule. Based on our data, the hepatitis B vaccination also leaves room for flexibility for the second dose and the third dose without the necessity of restarting the vaccination series or confirmation of the immune response to the vaccine.