Vaccine
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Randomized Controlled Trial
Safety and immunogenicity of dry powder measles vaccine administered by inhalation: a randomized controlled Phase I clinical trial.
Measles is a highly infectious respiratory disease which causes 122,000 deaths annually. Although measles vaccine is extremely safe and effective, vaccine coverage could be improved by a vaccine that is more easily administered and transported. We developed an inhalable dry powder measles vaccine (MVDP) and two delivery devices, and demonstrated safety, immunogenicity, and efficacy of the vaccine in preclinical studies. Here we report the first clinical trial of MVDP delivered by inhalation. ⋯ MVDP was well tolerated in all subjects. Most subjects had high baseline measles antibody titer which limited ability to measure the serologic responses, and may have limited the adverse events following vaccination. Additional studies in subjects without pre-existing measles antibody are needed to further elucidate the safety and immunogenicity of MVDP.
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The term vaccine hesitancy refers to delay in acceptance or refusal of vaccines despite the availability of vaccination services. Different factors influence vaccine hesitancy and these are context-specific, varying across time and place and with different vaccines. Factors such as complacency, convenience and confidence are involved. ⋯ Vaccine hesitancy was not defined consistently by the IMs and most interpreted the term as meaning vaccine refusal. Although vaccine hesitancy existed in all 13 countries, some IMs considered its impact on immunization programmes to be a minor problem. The causes of vaccine hesitancy varied in the different countries and were context-specific, indicating a need to strengthen the capacity of national programmes to identify the locally relevant causal factors and to develop adapted strategies to address them.
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Neurological adverse events following administration of the 17DD substrain of yellow fever vaccine (YEL-AND) in the Brazilian population are described and analyzed. Based on information obtained from the National Immunization Program through passive surveillance or intensified passive surveillance, from 2007 to 2012, descriptive analysis, national and regional rates of YFV associated neurotropic, neurological autoimmune disease, and reporting rate ratios with their respective 95% confidence intervals were calculated for first time vaccinees stratified on age and year. Sixty-seven neurological cases were found, with the highest rate of neurological adverse events in the age group from 5 to 9 years (2.66 per 100,000 vaccine doses in Rio Grande do Sul state, and 0.83 per 100,000 doses in national analysis). ⋯ This is the largest sample of YEL-AND already analyzed. Rates are similar to other recent studies, but on this study the age group from 5 to 9 years of age had the highest risk. As neurological adverse events have in general a good prognosis, they should not contraindicate the use of yellow fever vaccine in face of risk of infection by yellow fever virus.
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Bordetella pertussis is the etiologic agent of whooping cough and has been the target of vaccination for over fifty years. The latest strategies include the use of acellular pertussis vaccines that induce specific immunity against few virulence factors amongst which pertactin is included in three and five component acellular pertussis vaccines. ⋯ We here demonstrate that isolates not producing pertactin are capable of sustaining longer infection as compared to pertactin producing isolates in an in vivo model of acellular pertussis immunization. Loosing pertactin production might thus provide a selective advantage to these isolates in this background, which could account for the upraise in prevalence of these pertactin deficient isolates in the population.
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Randomized Controlled Trial Multicenter Study
Safety and immunogenicity of a recombinant hepatitis B vaccine manufactured by a modified process in renal pre-dialysis and dialysis patients.
Patients with renal insufficiency are hyporesponsive to vaccination, including to hepatitis B vaccines. A manufacturing process modification for a hepatitis B vaccine (mpHBV) was studied in renal pre-dialysis and dialysis patients. ⋯ Both formulations were immunogenic in this population but required more vaccinations to reach seroprotective levels than comparable regimens in healthy individuals, as expected. The relatively reduced SPRs seen in this population support the need for routine screening and re-dosing in this population.