Predictors of Booster Response to Hepatitis B Vaccine at 15 years of age: A Cross-Sectional School-Based Study.

BACKGROUND: The current consensus does not support the use of booster dose because of its anamnestic response in almost all children 15 years after universal infant hepatitis B virus (HBV) vaccination. However, in our clinical setting, numerous concerned parents request a booster administration for their children. We aimed to provide the possible predictors of booster response in adolescents before this booster administration. METHODS: This study comprised a series of cross-sectional serological surveys of HBV markers in 15-year-old individuals between 2008 and 2012. Data on serum hepatitis B surface antigen, hepatitis B surface antibody (anti-HBs), and liver-function biomarkers in a total of 887 senior high-school students were collected. There were two parts to this study: HBV seroepidemiology and booster-response analysis to identify the possible response predictors and decay factors after the HBV booster administration. RESULTS: The overall anti-HBs and hepatitis B surface antigen seropositivity rates were 34.7% and 0.7%, respectively, and the median anti-HBs titer was 3.3 mIU/mL. Six weeks after one dose of recombinant HBV vaccine, the overall booster-response rate in the double-seronegative recipients was 94% (471/501). Among the participants whose initial anti-HBs titers were undetectable or low, 72.4% (247/341) and 95.6% (153/160), respectively, reactivated their anti-HBs titers ≥ 100 mIU/mL about 6 weeks after the booster administration. The likelihood of postbooster anti-HBs titer reaching an adequate protective level increased with the prebooster titer. The female participants had stronger anamnestic responses compared to the male participants. CONCLUSION: We found that the female participants and prebooster anti-HBs titers above the detection limit of the immunoassay were good predictors of HBV booster response.

Therapeutic hypothermia brings favorable neurologic outcomes in children with near drowning.

A 1-year-10-month-old boy was admitted to our pediatric intensive care unit due to near drowning with pulmonary edema. A conventional ventilator with 100% oxygen supplementation was used initially, but was shifted to high frequency oscillatory ventilation as his oxygen saturation was around 84-88%. Therapeutic hypothermia was applied due to hypoxic ischemic encephalopathy with severe acidosis. His respiratory condition improved and he was extubated successfully on the 6th hospital day. The patient had no obvious neurological defects and he was discharged in a stable condition after 17 days of hospitalization. Our case report demonstrates the advantages of therapeutic hypothermia on survival and neurological outcomes in treating pediatric near drowning patients.

Hepatitis B virus vaccination booster does not provide additional protection in adolescents: a cross-sectional school-based study.

BACKGROUND: Current consensus does not support the use of a universal booster of hepatitis B virus (HBV) vaccine because there is an anamnestic response in almost all children 15 years after universal infant HBV vaccination. We aimed to provide a booster strategy among adolescents as a result of their changes in lifestyle and sexual activity. METHODS: This study comprised a series of cross-sectional serological surveys of HBV markers in four age groups between 2004 and 2012. The seropositivity rates of hepatitis B surface antigen (HBsAg) and its reciprocal antibody (anti-HBs) for each age group were collected. There were two parts to this study; age-specific HBV seroepidemiology and subgroup analysis, including effects of different vaccine types, booster response for immunogenicity at 15 years of age, and longitudinal follow-up to identify possible additional protection by HBV booster. RESULTS: Within the study period, data on serum anti-HBs and HBsAg in a total of 6950 students from four age groups were collected. The overall anti-HBs and HBsAg seropositivity rates were 44.3% and 1.2%, respectively. The anti-HBs seropositivity rate in the plasma-derived subgroup was significantly higher in both 15- and 18-year age groups. Overall response rate in the double-seronegative recipients at 15 years of age was 92.5% at 6 weeks following one recombinant HBV booster dose. Among the 24 recipients showing anti-HBs seroconversion at 6 weeks after booster, seven subjects (29.2%) had lost their anti-HBs seropositivity again within 3 years. Increased seropositivity rates and titers of anti-HBs did not provide additional protective effects among subjects comprehensively vaccinated against HBV in infancy. CONCLUSIONS: HBV booster strategy at 15 years of age was the main contributor to the unique age-related phenomenon of anti-HBs seropositivity rate and titer. No increase in HBsAg seropositivity rates within different age groups was observed. Vaccination with plasma-derived HBV vaccines in infancy provided higher anti-HBs seropositivity at 15-18 years of age. Overall booster response rate was 92.5% and indicated that intact immunogenicity persisted at least 15 years after primary HBV vaccination in infancy. Booster vaccination of HBV did not confer additional protection against HBsAg carriage in our study.

Different effects of probiotic species/strains on infections in preschool children: A double-blind, randomized, controlled study.

Treatment and prevention of pediatric infectious diseases of three commercial probiotic products were evaluated by a double-blind, randomized, controlled trial. Test subjects under age 5, 1062 in total, were distributed randomly into four groups. This investigation showed that L. casei rhamnosus can control bacterial, viral and respiratory infections; a multi-species probiotic reduced gastrointestinal disease significantly. Long-term consumption of L. rhamnosus T cell-1 decreased the incidence of bacterial infection.