Immunogenicity and reactogenicity of the human rotavirus vaccine, RIX4414 oral suspension, when co-administered with routine childhood vaccines in Chinese infants.

This study evaluated the immunogenicity of the human rotavirus (RV) vaccine (RIX4414) when co-administered with routine childhood vaccines in Chinese infants (NCT01171963). Healthy infants aged 6-16 weeks received 2 doses of either RIX4414 or placebo according to a 0, 1-month schedule. Infants received routine diphtheria-tetanus-acellular pertussis (DTPa) and oral poliovirus (OPV) vaccines either separately from or concomitantly with RIX4414/placebo (separate and co-administration cohorts, respectively). Anti-RV IgA seroconversion rates (one month post-dose-2) and seropositivity rates (at one year of age) were measured using ELISA. Immune responses against the DTPa and OPV antigens were measured one month post-DTPa dose-3 in the co-administration cohort. Solicited local and general symptoms were recorded for 8-days post-vaccination (total cohort). The according-to-protocol immunogenicity population included 511 infants in the separate cohort and 275 in the co-administration cohort. One month post-RIX4414 dose-2, anti-RV IgA seroconversion rates were 74.7% (95% confidence interval [CI]: 68.9-79.9) and 64.2% (95% CI: 55.4-72.3) in the separate and co-administration cohorts; seropositivity rates at one year of age were 71.5% (95% CI: 65.5-77.1) and 50.0% (95% CI: 40.9-59.1), respectively. One month post-DTPa dose-3, all infants in the co-administration cohort were seroprotected against diphtheria and tetanus, and seropositive for pertussis toxoid, pertactin and filamentous haemaglutinin. Two months post-OPV dose-3, seroprotection rates against anti-poliovirus types 1, 2 and 3 were >99% in the co-administration cohort. Reactogenicity profiles were similar in both cohorts. RIX4414 was immunogenic and well-tolerated in Chinese infants and did not appear to interfere with the immunogenicity and reactogenicity of co-administered routine childhood vaccines.

Human rotavirus vaccine (RIX4414) efficacy in the first two years of life: a randomized, placebo-controlled trial in China.

Rotaviruses (RV) are a major cause of severe gastroenteritis (GE) in children aged<5 y. For the first time in China, we assessed the efficacy of two oral doses of the human rotavirus vaccine (RIX4414) in infants during the first two years of life (113808/NCT01171963). Healthy infants aged 6-16 weeks were randomized (1:1) to receive two oral doses of either the RIX4414 vaccine/placebo according to a 0, 1 month schedule. Vaccine efficacy (VE) against severe RVGE was assessed from two weeks post-Dose 2 up until the end of the second RV season and calculated with its 95% confidence intervals (CI). The primary efficacy objective was met if the lower limit of the 95% CI on VE was ≥10%. Unsolicited symptoms reported during the 31-d post-vaccination follow-up period and serious adverse events (SAEs) reported throughout the study were assessed. Of 3333 enrolled infants, 3148 were included in the according-to-protocol efficacy cohort. Over two consecutive RV seasons, fewer severe RVGE episodes were reported in the RIX4414 group (n=21) vs. the placebo group (n=75). VE against severe RVGE was 72% (95% CI: 54.1-83.6); the lower limit of the 95% CI on VE was >10%. The number of unsolicited symptoms and SAEs reported was similar between both groups. Thirteen deaths (RIX4414=6; placebo=7) occurred during the study. All SAEs and deaths in the RIX4414 group were considered unrelated to vaccination. Two oral doses of RIX4414 vaccine provided a substantial level of protection against severe RVGE in Chinese children during the first two years of life.

[Evaluation on the safety of a group A + C meningococcal polysaccharide vaccine].

OBJECTIVE: To evaluate the safety of a group A + C meningococcal polysaccharide vaccine as part of a phase IV clinical trial. METHODS: The study area was divided into 108 clusters according to the principle of cluster randomization, stratified and paired sampling methods. 54 out of 108 clusters served as observation groups were administered A + C vaccine, while the rest 54 groups were administered Vi polysaccharide vaccine. An adverse event surveillance system was established to monitor the adverse events following the vaccination campaign. Identical form and methods were used for data collection to investigate the adverse events following the vaccination of both A+ C vaccine and Vi vaccine. RESULTS: 34,543 people were vaccinated, including 18,167 of whom received A + C vaccine, while the other 16,376 received Vi vaccine. The rates of immediate injection reaction and unsolicited non-serious adverse events from A + C vaccine group were 0.44% and 0.38% while of Vi vaccine group were 0.79% and 0.73% respectively. At the solicited adverse event survey on 3-day-post-vaccination, 1239 vaccinees were followed-up including 771 received A + C vaccine and 468 received Vi vaccine. The local injection reaction rate of A + C vaccine group on the 1st day was significantly higher (X2 = 13.98, P = 0.0002) than that of Vi vaccine group. Neither the local injection reaction rate nor the system reaction rate between both groups was significantly different on 2nd and 3rd day, post vaccination. It was not statistically different when comparing fever onset rate between those who received vaccine and those who did not, in each vaccine group. There were no serious adverse events observed. CONCLUSION: Results showed that the side effects of A + C vaccine and the Vi vaccine were mild and safe for vaccination campaigns targeting on populations at different age.

[Application of cluster randomization method on typhoid Vi vaccine trails].

OBJECTIVE: To describe the design and application of cluster randomized controlled method on typhoid Vi vaccine trial, and to assess the effect of implementation. METHODS: Simple size calculation of cluster-randomized trial was used to determine the sample size of the two groups and a vaccination campaign was conducted. The study group was given typhoid Vi vaccine and the control group was given meningococcal A vaccine. RESULTS: According to sample size calculation, a total sample of 96,121 participants was required and the study areas were divided into 108 clusters. In practice, 53 study clusters with 44,054 participants and 54 control clusters with 48,422 participants were stratified and matched according to size, location (urban or rural), characteristics (school, department, factory, demography) were randomized respectively. Confounding factors of two groups including age, sex, resident area, income, level of education were compared. It was found that the ratio of all confounding factors between the two groups were comparable and balanced. CONCLUSION: Confounding factors can be better controlled between study group and the control group by applying cluster-randomized method on vaccine trail which enabled the intervention to be more scientifically evaluated; The implementation of cluster randomization trial was simple and easy to be accepted.

A mass vaccination campaign targeting adults and children to prevent typhoid fever in Hechi; expanding the use of Vi polysaccharide vaccine in southeast China: a cluster-randomized trial.

BACKGROUND: One of the goals of this study was to learn the coverage, safety and logistics of a mass vaccination campaign against typhoid fever in children and adults using locally produced typhoid Vi polysaccharide (PS) and group A meningococcal PS vaccines in southern China. METHODS: The vaccination campaign targeted 118,588 persons in Hechi, Guangxi Province, aged between 5 to 60 years, in 2003. The study area was divided into 107 geographic clusters, which were randomly allocated to receive one of the single-dose parenteral vaccines. All aspects regarding vaccination logistics, feasibility and safety were documented and systematically recorded. Results of the logistics, feasibility and safety are reported. RESULTS: The campaign lasted 5 weeks and the overall vaccination coverage was 78%. On average, the 30 vaccine teams gave immunizations on 23 days. Vaccine rates were higher in those aged < or = 15 years (90%) than in adolescents and young adults (70%). Planned mop-up activities increased the coverage by 17%. The overall vaccine wastage was 11%. The cold chain was maintained and documented. 66 individuals reported of adverse events out of all vaccinees, where fever (21%), malaise (19%) and local redness (19%) were the major symptoms; no life-threatening event occurred. Three needle-sharp events were reported. CONCLUSION: The mass immunization proved feasible and safe, and vaccine coverage was high. Emphasis should be placed on: injection safety measures, community involvement and incorporation of mop-up strategies into any vaccination campaign. School-based and all-age Vi mass immunizations programs are potentially important public health strategies for prevention of typhoid fever in high-risk populations in southern China.