Levels of hepatitis B antibody titers are affected by age and doses gap time in children from a high endemic area of the western Amazon

Abstract

Background Despite completion of the vaccine schedule for hepatitis B virus (HBV), children may display levels of HBV surface antibodies (anti-HBs) that are considered inadequate for sufficient protection (<10 IU/L). Aims Our aim was to investigate if age and gap time between HBV vaccine doses may negatively affect the levels of anti-HBs in children, and if these relationships are modified by sex. Methods In a high-endemic HBV region of the western Brazilian Amazon we enrolled children who had completed the HBV vaccine schedule. All children underwent analysis of anti-HBs and a clinical examination. Results We included 522 children (mean age 4.3 ± 0.8 years; 50% male). Median anti-HBs was 28.4 [interquartile range (IQR) 5.4 to 128.6] IU/L and 32% had anti-HBs <10 IU/L. The median gap time from last to preceding dose was 2.4 [IQR 2.1 to 3.3] months. Levels of anti-HBs decreased with higher age (-42% per year increase [95%CI -56% to -24%], p<0.001), but not with longer gap time (+23% per month increase [95%CI -16% to +62%], p = 0.249). After adjusting for relevant confounders, gap time became significant (p = 0.032) and age remained a significant predictor of anti-HBs (p<0.001). Conclusion One third of assessed children displayed anti-HBs <10 IU/L. Levels of anti-HBs decreased with higher age and increased with longer gap time between the last two doses.

Seroprotection of Hepatitis B Vaccine in Dental Students Two Decades after Infant Immunization and the Possible Need for Revaccination

“…This confirms the findings of previous studies that the immunity effect of hepatitis B vaccine diminishes with time. 8,17,18 In comparison with previous studies conducted on the same age group, the percentage of participants showing low anti-HBs antibody titers after 21 years from infant vaccination is lower than previously detected in Asir region, Saudi Arabia, during the period from 2012 to 2013 (88.9%) 4 and in Canada (81.5%) during the period from 2013 to 2014. 19 On the other hand, it was higher than those detected in studies performed on medical students, Taibah University, Saudi Arabia (51%), 20 medical and dental students in Malaysia (66.14%), 21 and on Chinese subjects vaccinated with plasma-derived hepatitis B vaccine (35.6%).…”

Lack of relationship between 25-hydoxyvitamin D concentration and a titer of antibodies to hepatitis B surface antigen in children under 12 years of age

“…In children with 25(OH)D concentration < 20 ng/mL (subgroup 1), the average anti-HBs titer was significantly lower in comparison to subgroups 2 and 3, with a suboptimal and optimal concentration of 25(OH)D. The highest average anti-HBs titer was found in children with 25(OH)D concentration � 30 ng/mL (subgroup 3) and it was comparable with the average anti-HBs titer in children with 25(OH)D concentration of [20][21][22][23][24][25][26][27][28][29][30] ng/mL (subgroup 2).…”

“…The subgroup comprised 17 (4.8%) children aged 0.7-2 years, 27 (7.7%) children aged 3-5 years and 7 (2%) children aged 6-11 years. The concentration of vitamin 25(OH)D in the range [20][21][22][23][24][25][26][27][28][29][30] ng/mL was found in 22 (6.3%) children aged 0.7-2 years, in 80 (22.7%) children aged 3-5 years and in 58 (16.5%) aged 6-11 years. The concentrations of vitamin 25(OH)D < 20 ng/mL were found in 12 (3.4%) children from the 0.7-2 years of age subgroup, in 58 (16.5%) children from the 3-5 years of age subgroup and in 71 (20.1%) children from the 6-11 years of age subgroup (p = 0.000).…”

“…12.1% were seronegative one to six months after the receipt of the last dose, 21.7% three years after, and 58.3% five years post vaccination [ 26 ]. Similarly, among western Brazilian Amazon children aged 2 to 5 years (four doses, the first a monovalent given at birth and the remaining three pentavalent vaccines given at 2, 4 and 6 months, 10μg), 32% subjects had anti-HBs titer < 10 IU/L [ 27 ]. By contrast, 44% of Senegalese children vaccinated in infancy with a monovalent recombinant vaccine were seronegative, including 20.9% under the age of five, 66.3% of 5- to 10-year-olds and 59% of children above the age of 10 years [ 28 ].…”

Assessment of COVID-19 vaccination effectiveness

“…osoby starsze [63]. Ogólne doświadczenie wakcynologiczne sugeruje, że taka dawka poprawia znacznie ochronę przed chorobą na dłuższy czas, szczególnie że nie jest podawana w odstępie 2 tygodni, ale tym razem więcej niż kilku miesięcy [64]. Skuteczność takiego podejścia potwierdzają pośrednio badania zaszczepionych ozdrowieńców.…”