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Pertussis continues to circulate in Chinese communities and older children, adolescents and adults are sources of infection for unprotected infants. Two studies conducted in Jiangsu Province in the People's Republic of China assessed the immunogenicity, reactogenicity and safety of Boostrix(), a combined reduced antigen content diphtheria-tetanus-acellular pertussis vaccine (dTpa) when administered as a booster dose to children 6 to 8 years of age. Immunogenicity was assessed before and one month after vaccination in a subset. Reactogenicity was assessed over a 4-day follow-up using diary cards. A total of 690 Chinese subjects were enrolled. Boostrix() was well tolerated. One month after the booster dose, 100% of dTpa recipients had seroprotective antibody concentrations against diphtheria and tetanus. The percentage of subjects with a response against pertussis antigens (using locally defined cut-offs) was 91.9% for pertussis toxoid, 98.8% for filamentous hemagglutinin, and 100% for pertactin. The exploratory analysis showed no statistically significant differences between dTpa or diphtheria-tetanus vaccine in terms of the percentage of subjects with seroprotective antibodies against diphtheria or tetanus. These studies demonstrate that Boostrix() is well tolerated and immunogenic when administered as a booster dose to 6 to 8 year old Chinese children previously immunized with a combined diphtheria-tetanus-pertussis vaccine. Introduction of dTpa into the routine Chinese immunization schedule would provide booster vaccination against pertussis without the addition of further injections into the Chinese vaccination schedule and is likely to promote improved pertussis control in older children.

This study was undertaken to assess the immunogenicity, reactogenicity and safety of two doses of an oral live-attenuated human rotavirus vaccine, strain RIX4414 (Rotarix()) in an Indian setting.The seroconversion rate observed one month post-dose 2 in the RIX4414 group 58.3% [95% CI: 48.7; 67.4] was significantly higher when compared to the placebo group 6.3%; [95% CI: 2.5; 12.5]. The reactogenicity and safety profile was similar for both groups.Healthy infants (N = 363), approximately eight weeks of age were enrolled to receive two doses of RIX4414 vaccine (n = 182) or placebo (n = 181) separated by one month. To assess the immune response, blood samples were taken before vaccination and one month post-dose 2 of RIX4414/placebo. Solicited symptoms were collected for eight-days post each dose and safety data was collected throughout the study.Two doses of RIX4414 (Rotarix()) were immunogenic, had a good safety profile and were well-tolerated when administered to healthy Indian infants.ClinicalTrials.gov; NCT00289172; eTrack 103792.

The response to booster vaccination at 15-18 months of age and the presence of immune memory in 10-month old children, primed with a new combined diphtheria-tetanus-hepatitis B-whole cell pertussis vaccine extemporaneously mixed with Haemophilus influenzae type b-tetanus toxoid conjugate (DTPw-HBV/Hib) from new antigen sources and containing 2.5 microg polyribosyl-ribitol-phosphate (PRP) was assessed. Primary vaccination with the new DTPw-HBV/Hib vaccine was immunogenic and of comparable tolerability to commercially available Tritanrix HepB/Hiberix. Children were boosted with DTPw-HBV, DTPw-HBV/Hib or separate DTPw-HBV+Hiberix. Immune memory was assessed through administration of 10 microg PRP polysaccharide. Anti-PRP antibody GMCs increased substantially after the challenge in DTPw-HBV/Hib-primed subjects indicating the presence of immune memory. One month after the booster dose, 100% of subjects had seroprotective antibody concentrations against PRP, diphtheria and tetanus, >95% were seroprotected against hepatitis B, > or =94.0% had a pertussis booster response. Substantial increases in antibody GMCs against all antigens were observed. Swelling >20 mm was the most common Grade 3 solicited symptom reported (up to 26.0% of subjects). Fever >39.5 degrees C was uncommon (>2.5%). Eleven large swelling reactions were reported; none involved an adjacent joint. One serious adverse event occurred that was considered unrelated to vaccination. This new DTPw-HBV/Hib vaccine with new vaccine components and 2.5 microg PRP induced effective priming against Hib evidenced by a vigorous anamnestic response on exposure to PRP polysaccharide. The booster dose was immunogenic and the safety profile was acceptable. Combined DTPw-HBV and DTPw-HBV/Hib vaccines using new vaccine antigen sources will promote continued supply of combined DTPw-based vaccines to global mass vaccination campaigns.

Acute hepatic failure (AHF) can be caused by a variety of viruses, drugs, toxins and metabolic disorders.A prospective study was conducted to determine the aetiology and outcome of AHF in Thai children aged 1-15 years.All serum samples were tested for anti-HAV IgM, HBsAg, anti-HBc IgM, anti-HCV, anti-HEV IgM and anti-dengue IgG and IgM. Further individual investigations were done according to the clinical impression.Forty subjects were enrolled from 14 centres during February 2000 to December 2001. Five cases were excluded owing to a lack of evidence of encephalopathy. The causes of AHF were dengue infection in 12 (34.3%), Wilson disease in 2 (5.7%), T-cell lymphoma in 2 (5.7%), ischaemic hepatitis in two (5.7%), haemophagocytic syndrome in one (2.8%), CMV in 2 (5.7%), Reye syndrome in one (2.8%) and unknown in 13 (37.1%) patients. The fatality rate was 68.6%. Eight of 24 (33.3%) deaths were caused by dengue infection.Improvements in sanitation and socio-economic status as well as the implementation of hepatitis B vaccine in the Extended Programme on Immunization (EPI) are likely to be the reasons for the observed absence of AHF caused by hepatitis A and B. The study showed that dengue infection, on the other hand, was a major cause of AHF in Thailand.