Immunogenicity of the pentavalent DTwP-HB-Hib vaccine (Shan-5) used in the Thai Expanded Program on Immunization compared to the hexavalent DTaP-HB-Hib-IPV and DTwP-HB-Hib (Quinvaxem) vaccines administered to infants at 2, 4, 6 months of age.

BACKGROUND: The pentavalent DTwP-HB-Hib (Shan-5) vaccine was first introduced into the Thailand Expanded Program on Immunization (EPI) in 2019. The Shan-5 vaccine is administered to infants at 2, 4, and 6 months of age, after initial vaccination with monovalent hepatitis B (HepB) and Bacillus Calmette-Guérin (BCG) vaccines at birth. This study compared the immunogenicity of the HepB, diphtheria, tetanus, and Bordetella pertussis antigens incorporated in the EPI Shan-5 vaccine versus the optional pentavalent (DTwP-HB-Hib) Quinvaxem and hexavalent (DTaP-HB-Hib-IPV) Infanrix-hexa vaccine. METHODS: Three-dose Shan-5-vaccinated children were prospectively enrolled at the Regional Health Promotion Centre 5, Ratchaburi province, Thailand, between May 2020 and May 2021. Blood sampling was performed at months 7 and 18. The levels of HepB surface antibody (anti-HBs), anti-diphtheria toxoid (DT) IgG, anti-tetanus toxoid (TT) IgG, and anti-pertussis toxin (PT) IgG were evaluated using commercially available enzyme-linked immunoassays. RESULTS: Anti-HBs levels of ≥10 mIU/mL were achieved in 100 %, 99.2 %, and 99.2 % of infants in the Shan-5 EPI group, hexavalent group and Quinvaxem group one month after four dose immunization (at 0, 2, 4, 6 months of age), respectively. The geometric mean concentrations of the EPI Shan-5 and hexavalent groups were comparable but were higher than those of the Quinvaxem group. At one month after primary vaccination (month 7), infants in the Shan-5 EPI group had significantly higher levels of anti-DT IgG, anti-TT IgG, and anti-PT IgG than infants in the hexavalent and Quinvaxem groups. CONCLUSIONS: The immunogenicity of the HepB surface antigen in the EPI Shan-5 vaccine was similar to that achieved by the hexavalent vaccine, but was higher than that achieved by the Quinvaxem vaccine. The Shan-5 vaccine is highly immunogenic and generates robust antibody responses after primary immunization.

Clinical manifestations, treatment outcomes, and prognostic factors of pediatric anti-NMDAR encephalitis in tertiary care hospitals: A multicenter retrospective/prospective cohort study.

OBJECTIVE: Anti-NMDAR encephalitis is an acute autoimmune neurological disorder that is increasingly recognized in pediatric populations. Several studies of the disorder have been conducted worldwide but there are few publications in Thailand. Here, we describe the clinical manifestations, treatment outcomes, and prognostic factors in children with anti-NMDAR encephalitis. METHODS: Between January 2007 and September 2017, we conducted a retrospective/prospective cohort study of children diagnosed with anti-NMDAR encephalitis from three tertiary care hospitals in Thailand: King Chulalongkorn Memorial Hospital, Chonburi Hospital, and Prapokklao Hospital. We assessed the Modified Rankin Score (mRS) score for each participant to measure severity of disease and treatment outcome at baseline, 12, and 24 months. RESULTS: We recruited 14 participants (1-13 years with median age 8.4 years). Participants were followed up for a median of 20.5 months. Clinical manifestations included behavioral dysfunction (100%), movement disorder (93%), speech disorder (79%), sleep disorder (79%), and seizures (79%). All patients received first-line immunotherapy (corticosteroids: 100%, intravenous immunoglobulin: 79%, plasma exchange: 21%). Second-line immunotherapy (cyclophosphamide) was administered to 57% of patients. During the first 12 months, 8 patients (62%) achieved a good outcome (mRS ≤ 2). At 24 months, 9 patients (81%) had achieved a good outcome. Altered consciousness and central hypoventilation were predictors of poor outcome. (p < 0.05). CONCLUSIONS: We observed similar clinical manifestation of anti-NMDAR encephalitis in Thai children to those reported in other countries. Furthermore, the percentage of patients with good outcomes in our study was comparable with previous studies. Further studies are required to investigate other populations in other regions of Thailand.