ABSTRACT
Group B Streptococcus (GBS) is a leading cause of meningitis and sepsis in infancy, but burden of disease data are scarce for Asia. We performed two hospital-based, prospective, descriptive, observational studies using similar protocols in the Philippines and Thailand to evaluate neonatal GBS disease epidemiology. Infants aged <90 days with a GBS-positive culture from normally sterile sites using routine microbiological standards were eligible for inclusion. Awareness of GBS symptoms was raised by informing all women at delivery and follow-up for 90 days post-delivery. Infections were classified as early onset disease (EOD) if they occurred within 6 days of birth and late Onset disease (LOD) if they occurred 7-89 days after birth. Due to ethical requirements in Thailand, consent for study participation, including periodic post-discharge telephone calls, was obtained at delivery. Parents in the Philippines gave consent for study participation at case identification. The clinical outcomes of GBS infections were recorded. During the 6-month study period, two cases (one fatal) of EOD were identified among 8,409 live births at the study hospitals in Thailand and three cases (two fatal) of EOD were identified among 11,768 live births reported at the study hospitals in the Philippines. Incidence rates per 1,000 live births were 0.2 (95% CI: 0.0-0.8) and 0.3 (95% CI: 0.1-0.8) in Thailand and the Philippines, respectively. There were no cases of reported LOD. The low number of cases precluded analysis of serotype distribution and case fatality rates. Large epidemiological studies are needed to better understand the factors influencing GBS infection incidence in Asia.
Subject(s)
Infant, Newborn, Diseases/epidemiology , Sepsis/epidemiology , Streptococcal Infections/epidemiology , Streptococcus agalactiae , Female , Humans , Incidence , Infant , Infant, Newborn , Infant, Newborn, Diseases/microbiology , Male , Philippines/epidemiology , Prospective Studies , Risk Factors , Sepsis/microbiology , Serogroup , Streptococcal Infections/microbiology , Thailand/epidemiologyABSTRACT
BACKGROUND: Non-adjuvanted seasonal influenza vaccines show only modest efficacy in young children. This study compared the immunogenicity, reactogenicity and safety of the MF59-adjuvanted trivalent subunit vaccine (aTIV) with two non-adjuvanted trivalent vaccines, TIV-1, the non-adjuvanted version of aTIV, and TIV-2, a split virion vaccine. METHODS: 6078 children received two doses of aTIV (n=3125), TIV-1 (n=1479), or TIV-2 (n=1474) four weeks apart (Days 1 and 29). Children aged 6 to <36 months and 36 to <72 months received 0.25 mL and 0.50 mL doses, respectively. Immunogenicity was assessed by hemagglutination inhibition (HI) assay (n=2435) on Days 1, 29, 50 and 209. Safety was assessed up to Day 394. RESULTS: After the second vaccination (Day 50), the aTIV group showed significantly higher geometric mean HI titers and seroconversion rates than the TIV-1 or TIV-2 groups against all homologous and heterologous strains. The difference was enhanced at HI titers ≥110. aTIV elicited a faster, more persistent antibody response, with significantly higher titers in the aTIV group after one vaccination (Day 29) and after six months (Day 209) than in either TIV group. aTIV was more reactogenic than were TIV-1 and TIV-2 but rates of severe adverse events were very low for all three vaccines. CONCLUSION: In infants and young children, the MF59-adjuvanted vaccine induced substantially faster (after one dose), higher, persistent HI titers than the non-adjuvanted vaccines, with consistently higher seroprotection rates at increased threshold HI titers. This trial is registered at clinicaltrials.gov: NCT01346592.
