Age-dependent decrease of anti-HBs titers and effect of booster doses using 2 different vaccines in Palestinian children vaccinated in early childhood

Abstract

Immunization against hepatitis B virus (HBV) has proven to be highly effective and led to significant reduction of new infections worldwide. However, protective immunity measured by anti-HBs titers may decrease to critical levels in the years after basal immunization, particularly in case of exposure to HBV variants different from the vaccine strain. We tested 400 Palestinian children between one and 19 years of age for their anti-HBs titer, challenged the immune memory of those with low or absent anti-HBs with 2 types of hepatitis B vaccines and determined thereafter the anti-HBs titer. At the age of one, 92.2% of the children presented with protective anti-HBs titers (≥ 10 mIU/ml) with the majority having ≥ 100 mIU/ml. Protective immunity was still high at ages 2 (87.5%) and 4 (95%), declining by age 5 and 6 (from 69.2% to 66.7%) and down to an average of 39.8% between the ages of 7 and 19. 160 children with a nonprotective or low immune response challenged with either the yeast-derived Engerix-B or the mammalian cell-derived preS1-containing Sci-B-Vac vaccine showed an anamnestic immune response. 92.4% and 85.9% of the children challenged with one dose Sci-B-Vac and Engerix-B presented with anti-HBs titers >100 mIU/ml respectively. Our results reveal that vaccine-induced protective anti-HBs titers against HBV decrease rapidly beyond the age of 6 in Palestinian children, but can be strongly enhanced with a single booster vaccine dose, independent of brand and antigen composition. Our data suggest that a booster vaccine dose against HBV during school years may be useful.

Changes and analysis of anti‐HBs titres after primary immunization in 1‐ to 16‐year‐old Chinese children: A hospital‐based study

“…Figure clearly indicates that the protective levels waned with increasing age between 1 and 8 years old, the percentage of lower concentrations declined more rapidly and that of higher titres kept relatively stable, especially the rate of high‐responders without showing obvious increasing or decreasing trend, suggesting that high antibody levels may be maintained for longer. Some studies also demonstrated that antibody levels showed a significant decline in children after hepatitis B vaccination in infancy . The decline of antibody concentrations may be associated with hepatitis B vaccine type, dosage, different vaccination programmes, physical quality and vaccination age …”

“…Some studies also demonstrated that antibody levels showed a significant decline in children after hepatitis B vaccination in infancy. [14][15][16] The decline of antibody concentrations may be associated with hepatitis B vaccine type, dosage, different vaccination programmes, physical quality and vaccination age. [17][18][19][20] Surprisingly, the proportion of protected anti-HBs titres slowly increased for children older than 8 years old, and the trend in antibody levels for children aged 9-16 declined compared to that in the 1-9 age groups, being >10 mIU/mL and of >100 mIU/mL, respectively.…”

Assessment of seroepidemic conditions of hepatitis B virus among people under 29 years of age and evaluation of the hepatitis B vaccine after 22 years in Jiangsu Province, China

“…There are many factors influencing the effectiveness of the vaccination. Some studies found that antibody levels showed a significant decline in children after HB vaccination in infancy [36][37][38]. One potential reason may be vaccination age [39,40].…”

Booster Dose Vaccine Response among Children Who were Primary Hepatitis B Vaccine Non-Responders and Sensitive Groups Concerning Vaccine Response

“…Additionally, both anti-HBs seroconversion rates and anti-HBs GMCs in T6 after the third booster dose increased rapidly in T7. So, the significant difference about the increased aspect of seroconversion rate and GMCs between T1 and T7 and the rapid decrease in T6 despite two dose vaccination are related with reminding, anti-HBs titer before vaccination and the checking time of anti-HBs rather than the number of reminding doses (17,32,33).…”