Immunogenicity and safety of two doses of a paediatric hepatitis A vaccine in thai children: comparison of three vaccination schedules

As fewer children in Thailand are exposed to hepatitis A virus (HAV) and so do not have seroprotective anti-HAV antibodies, they are becoming an important source of HAV transmission. A flexible HAV vaccination schedule would facilitate incorporation of the vaccine into existing immunization programmes, and we compared the immunogenicity and safety of three HAV immunization schedules. An open, randomized, clinical trial was carried out in which healthy children were given a primary dose of the inactivated hepatitis A vaccine, Avaxim 80 paediatric, with a booster dose 6, 12 or 18 months later. Anti-HAV geometric mean concentrations (GMC), seroconversion rates, and GMC ratios (GMCR) of the three schedules were compared and reactogenicity was evaluated. Seroconversion rates were above 98 per cent (per group) up to the booster. The three schedules were equivalent in terms of GMCRs, each eliciting a large booster effect. Local reactions were reported for fewer than 9 per cent of each group after dose one and less frequently after the booster dose. Injection site pain, gastrointestinal tract disorders and fever were the most commonly reported adverse events. No vaccine-related serious adverse events were reported. It was concluded that the hepatitis A vaccine, Avaxim 80 paediatric, is safe and immunogenic when given as a two-dose schedule to healthy seronegative children aged 5-10 years, with the second dose given at either 6, 12 or 18 months after the first.     

Hospital-based epidemiologic survey of malignancies in children infected with human immunodeficiency virus in Thailand

To determine the incidence and spectrum of malignancies in human immunodeficiency virus-infected children, we surveyed 48 hospitals in Thailand between 1996 and 2000. There were 23 children (14 boys and 9 girls; average age at diagnosis of malignancy, 4.2 years), and the incidence rate was 0.6 per 1000 person-years. The most common malignancy was lymphoma (87.0%). The prognosis was poor.     

Epidemiology of invasive meningococcal disease in 13 government hospitals in Thailand, 1994-1999.

This study was conducted to elucidate the magnitude of problem and the clinical course of invasive meningococcal infection from 13 government hospitals in Thailand between 1994 and 1999. Thirty-six strains of Neisseria meningitidis were isolated from 16 blood and 24 cerebrospinal fluid specimens; 4 patients had positive culture in both blood and CSF. Of the 16 strains, 9 (56.3%) were serogroup B. Seventy-one and eighty-four percent of the isolates were susceptible to penicillin and cefotaxime/ceftriaxone respectively. Five out of six penicillin-nonsusceptible strains were found to be relatively resistant to penicillin with the MIC of 0.125 microg/ml. Of 33 patients whose medical records were available, 21 were males and 12 were females, with a mean age of 11.2 years. Fifteen patients (45.5%) presented with meningococcemia and 18 patients (54.5%) presented with meningococcal meningitis. Hypotension and purpura were found in 24.2% and 33.3% of patients respectively. The overall mortality rate was 9.1%. In conclusion, meningococcal disease is not common in Thailand, meningococcemia is a life-threatening condition whereas meningococcal meningitis is much less severe. The prevalence of meningococci relatively resistant to penicillin seems to be increasing.     

Cost-utility analysis of 10- and 13-valent pneumococcal conjugate vaccines: Protection at what price in the Thai context?

Objective

This study aims to evaluate the costs and outcomes of offering the 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) in Thailand compared to the current situation of no PCV vaccination.

Methods

Two vaccination schedules were considered: two-dose primary series plus a booster dose (2 + 1) and three-dose primary series plus a booster dose (3 + 1). A cost-utility analysis was conducted using a societal perspective. A Markov simulation model was used to estimate the relevant costs and health outcomes for a lifetime horizon. Costs were collected and values were calculated for the year 2010. The results were reported as incremental cost-effectiveness ratios (ICERs) in Thai Baht (THB) per quality adjusted life year (QALY) gained, with future costs and outcomes being discounted at 3% per annum. One-way sensitivity analysis and probabilistic sensitivity analysis using a Monte Carlo simulation were performed to assess parameter uncertainty.

Results

Under the base case-scenario of 2 + 1 dose schedule and a five-year protection, without indirect vaccine effects, the ICER for PCV10 and PCV13 were THB 1,368,072 and THB 1,490,305 per QALY gained, respectively. With indirect vaccine effects, the ICER of PCV10 was THB 519,399, and for PCV13 was THB 527,378. The model was sensitive to discount rate, the change in duration of vaccine protection and the incidence of pneumonia for all age groups.

Conclusions

At current prices, PCV10 and PCV13 are not cost-effective in Thailand. Inclusion of indirect vaccine effects substantially reduced the ICERs for both vaccines, but did not result in cost effectiveness.     

Development of a culturally appropriate health-related quality of life measure for human immunodeficiency virus-infected children in Thailand

Aim: Develop a reliable and valid self-report health-related quality of life (HRQOL) instrument for human immunodeficiency virus (HIV)-infected children in Thailand. Methods: The Thai Quality of Life for HIV-infected Children instrument, the ThQLHC (an HRQOL measure that uses the Pediatric Quality of Life Inventory as a generic core and a 17-item HIV-targeted scale), was developed and administered cross-sectionally to 292 HIV-infected children in Thailand. The disease-targeted scale included HIV-related symptoms, ability to adhere with their treatment regimens and self-image. The internal consistency reliability (Cronbach's α) and construct validity of the ThQLHC scales were then evaluated. Results: Internal consistency reliability coefficients ranged from 0.57 to 0.82, with four of five scales reaching the minimal acceptable level (>0.70). Significant associations were found between poor HRQOL and poor self-rated disease severity, care giver's rated overall quality of life, cluster of differentiation (CD) 4 percent and plasma HIV ribonucleic acid level. Conclusion: Reliable and valid disease-targeted HRQOL measures for HIV-infected children are essential in the assessment of therapeutic effectiveness. The findings of this cross-sectional survey provide support for the reliability and validity of the ThQLHC as an HRQOL outcome measure for HIV-infected Thai children.