Immunogenicity and safety of an AS03(A)-adjuvanted H5N1 influenza vaccine in a Taiwanese population.

BACKGROUND/PURPOSE: A multicenter study (NCT00449670) conducted across Taiwan, Singapore, Hong Kong and Thailand evaluated the safety and manufacturing consistency of four formulations of an AS03(A)-adjuvanted H5N1 vaccine in terms of immune response against the vaccine-homologous strain (A/Vietnam/1194/2004). This manuscript presents data from the Taiwanese population. METHODS: A total of 400 individuals, aged 18-60 years, were randomized into six groups (2:2:2:2:1:1 ratio) to receive two doses (21 days apart) of one of the four adjuvanted formulations (H5N1-AS03(A)-groups) or one of the two nonadjuvanted formulations (H5N1-DIL-groups). Blood samples collected before vaccination (Day 0) and 21 days after each vaccine dose were analyzed using hemagglutination inhibition (HI) assay. Adverse events were recorded. RESULTS: All four AS03(A)-adjuvanted formulations induced comparable immune responses against the A/Vietnam/1194/2004 strain; following the second dose, immune response in terms of HI antibodies was higher in the H5N1-AS03(A)-groups {seroprotection rate=91.6% [95% confidence interval (CI): 87.9-94.4]; geometric mean titer (GMT)=177.6 (95% CI: 153.2-206.0)} compared with the H5N1-DIL-groups [seroprotection rates=5.0% (95% CI: 1.4-12.3); GMT=6.3 (95% CI: 5.4-7.4)]. Immune response against the heterologous A/Indonesia/05/2005 strain was also stronger in the H5N1-AS03(A)-groups [seroprotection rate=45.6% (95% CI: 40.0-51.4); GMT=20.5 (95% CI: 17.8-23.7)] compared with the H5N1-DIL groups [seroprotection rate=0.0% (95% CI: 0.0-4.5); GMT=5.0 (95% CI: 5.0-5.0)]. The overall reactogenicity profile of the adjuvanted formulations was clinically acceptable. CONCLUSION: The AS03(A)-adjuvanted H5N1 influenza vaccine formulations induced stronger immune response against the vaccine-homologous and heterologous strains than the nonadjuvanted formulations. The AS03(A)-adjuvanted H5N1 vaccine demonstrated a good immunogenicity and an acceptable safety profile in the Taiwanese population.

Population-based incidence and burden of childhood intussusception in Jeonbuk Province, South Korea.

OBJECTIVES: The aim of this study was to describe the clinical characteristics of childhood intussusception and to estimate the incidence rate of intussusception before the introduction of rotavirus vaccines in Korea. METHODS: Demographic, clinical, diagnostic, treatment, and outcome data for patients aged <5 years who were diagnosed with intussusception in Jeonbuk Province, South Korea from January 2000 through December 2002, were retrospectively collected using a standardized data collection instrument. RESULTS: During the 3-year period, 408 patients were diagnosed with intussusception; 82.8% of children were aged <24 months. Predominant signs and symptoms were vomiting (64.5%), bloody stool (43.9%), and abdominal pain/irritability (41.9%). The combination of ultrasound and barium or air enema was the most frequently used diagnostic approach (38.7%). Three hundred and thirteen patients (76.7%) were treated by radiologic reduction, 88 (21.6%) patients were treated by surgical intervention, and the remaining seven patients had no treatment. The mean annual incidence rate of intussusception in Jeonbuk Province was 236/100,000 among children aged <2 years and 106/100,000 among children aged <5 years. CONCLUSIONS: This retrospective study provides a background incidence rate of childhood intussusception in Korean children before the introduction of the rotavirus vaccine.