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Updated: Dec 8, 2025
An Optimized Hemagglutination Inhibition HI Assay to Quantify Influenza-specific Antibody Titers
Published on: December 1, 2017
Variable anti-HBs antibody titers in vaccinated birth cohorts - A cross-sectional population-based study
Alexandru Istrate1, Doina Azoicăi2, Ariana Almaş1
1Clinical Hospital of Infectious Diseases, Cluj-Napoca, Romania, 23, Iuliu Moldovan Street, 400348 Cluj-Napoca, Romania.
Insights
Hepatitis B (HB) vaccination provides long-term protection for two decades, suggesting booster doses may not be necessary for most. Further research is needed for specific populations.
Area of Science:
- Immunology
- Vaccinology
- Public Health
Background:
- Hepatitis B (HB) vaccination was introduced in 1995.
- Catch-up campaigns targeted unvaccinated individuals in 2000-2003 and 2004-2008.
- This resulted in distinct birth cohorts with varying vaccination histories.
Purpose of the Study:
- To assess anti-HBs antibody titers in different birth cohorts.
- To evaluate the long-term effectiveness of the HB vaccine.
- To determine the need for booster doses.
Main Methods:
- Included outpatients and hospitalized patients with measured anti-HBs titers (April 2014 - December 2018).
- Compared anti-HBs titers across birth cohorts using Lexis surfaces.
- Evaluated acute HB infections in vaccinated and unvaccinated groups.
Main Results:
- The 1995-2006 birth cohort (vaccinated post-delivery) showed lower protective titers (41.3%) compared to other cohorts.
- Cohorts vaccinated at birth or via catch-up campaigns had higher protective titers (67.0% - 74.3%).
- Four breakthrough acute HB infections occurred in vaccinated individuals; unvaccinated individuals showed 44.8% protective titers, likely from natural infection.
Conclusions:
- HB vaccination demonstrates long-term protection up to two decades post-primary immunization.
- Booster doses appear unsupported for the general population based on current findings.
- Further studies are recommended to assess booster dose necessity in specific populations.
Background:
After the introduction of hepatitis B (HB) vaccination in 1995 in newborns, two catch-up campaigns targeted unvaccinated 9 year old in 2000-2003 (born 1991-1994) and the 18 year old in 2004-2008 (born 1986-1990), resulting in several birth-cohorts. Our objective was to assess the anti-HBs titers in each birth-cohort.
Methods:
We included all outpatients (78.5%) and hospitalized patients with measured anti-HBs antibody titers in the Teaching Hospital of Infectious Diseases, Cluj-Napoca, Romania, during April 2014 - December 2018 (without HB history). We compared the anti-HBs titers in all birth-cohorts using the Lexis surfaces (titers by age, time period and cohort patterns). We also evaluated the number of acute HB in the corresponding inpatient birth-cohorts and special groups.
Results:
We included 2963 participants, mean age = 31.0 ± 14.2, 64.1% women. The birth-cohort 1995-2006, vaccinated after delivery (n = 424, 3-dose HB vaccine coverage > 90%), had significantly lower protective titers (41.3% >10 mIU/mL) compared to the other birth-cohorts: born after 2007 (also vaccinated at birth, 67.0%, n = 106), 1991-1994 (age 9, 74.3%, n = 847), 1986-1990 (age 18, 71.3%, n = 543). In the unvaccinated cohort (n = 1043, mean age = 45.5 ± 12.4) protective titers were found in 44.8%, probably after self-limited HB infection. Concordant results were found using the proportion of patients with detectable or robust titers, and median or geometric mean titers. Four breakthrough acute HB infections were hospitalized of the corresponding vaccinated cohorts (birth years 1988, 1990, 1995, 1996). Data on a few tested infants (n = 47, not included in the main study) demonstrated good protection, 88.9%.
Conclusions:
Our study demonstrated the long-term evidence of protection of HBV vaccine at two decades following the primary immunization and a booster seems unsupported. Further studies should be done to assess the need of a booster dose within the general population and special groups.
