Vaccine
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Comparative Study
The development of vaccine viruses against pandemic A(H1N1) influenza.
Wild type human influenza viruses do not usually grow well in embryonated hens' eggs, the substrate of choice for the production of inactivated influenza vaccine, and vaccine viruses need to be developed specifically for this purpose. In the event of a pandemic of influenza, vaccine viruses need to be created with utmost speed. ⋯ Two approaches were followed, the classical reassortment approach and the more recent reverse genetics approach. This report describes the development and the characteristics of current pandemic H1N1 candidate vaccine viruses.
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Due to the advent of the new influenza A (H1N1) strain in 2009, many countries introduced mass immunization programs. Healthcare workers (HCWs) were amongst the key groups targeted for the vaccine in these programs. However, experience with the seasonal influenza vaccine has shown that there are multiple barriers related to the attitudes and perceptions of the population which influence uptake. ⋯ While studies reported high rates of willingness to receive the vaccine, in reality these did not transpire. Aside from promoting seasonal flu vaccination, authorities need to start educational campaigns much earlier in a pandemic. Programs that are simultaneously launched with the introduction of the vaccine will not be as successful, as those which have built momentum alongside the pandemic.
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Randomized Controlled Trial Multicenter Study
Influenza A (H1N1) 2009 two-dose immunization of US children: an observer-blinded, randomized, placebo-controlled trial.
The goal of this pediatric clinical trial was to assess the safety and immunogenicity of two different doses of a monovalent inactivated pandemic (H1N1) 2009 vaccine in US children aged 6 months to 9 years of age. Randomized, observer-blinded, US multicenter phase 2 study assessing 2 doses of vaccine given 21 days apart in 474 children aged 6-35 months or 3-9 years. Children in each age group were randomly assigned to receive either a pandemic (H1N1) 2009 vaccine containing 7.5 or 15 μg of hemagglutinin (HA) or placebo in a 4:4:1 ratio. ⋯ A second dose of A H1N1 vaccine further increased HI antibody responses with seroprotection and seroconversion rates reaching 90-99% in both age groups. Interestingly, the pandemic (H1N1) 2009 vaccine formulations elicited similar rates of solicited and unsolicited injection site and systemic reactions as the placebo. The data therefore demonstrate the high level immunogenicity in infants and children of an (H1N1) 2009 influenza vaccine displaying a safety and reactogenicity profile similar to placebo.
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Parents' attitudes toward MMR vaccine and measles, mumps and rubella infections relate to their child's MMR status, therefore improving these attitudes is central to improving current suboptimal MMR uptake. However, no study has yet combined evidence-based, comprehensive and psychometrically validated assessment of these attitudes with reliable objective MMR status data, in order to identify through multivariate analyses the strongest attitudinal predictors of MMR uptake for interventions to target. The present study fills this lacuna by developing and testing a robust evidence-based MMR attitudes measurement instrument. ⋯ The measurement instrument is robust on multiple validity and reliability dimensions, and is appropriate for use in research and practice as a tool for designing and evaluating interventions. Parents appear to act in line with their attitudes toward MMR vaccine, though attitudes toward measles infection bore little relation to MMR uptake. This study indicates populations and attitudes to be prioritized in MMR uptake improvement interventions.
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Comparative Study
Evaluation of the reliability, validity and practicality of 3 measures of acute pain in infants undergoing immunization injections.
There is a need to identify a primary measure of infant pain that can be used to assess pain in infants undergoing vaccine injections in order to facilitate vaccine outcomes research. The aim of the present study was to determine the reliability, validity and practicality of 3 measures of acute pain in infants; the Modified Behavioural Pain Scale (MBPS), Neonatal Infant Pain Scale (NIPS), and Face Legs Activity Cry Consolability Scale (FLACC). Five raters rated pain from videotapes in 120 infants aged 2-6 months undergoing vaccine injections that participated in a randomized controlled trial designed to compare pain responses between two vaccines, DPTaP-Hib vaccine and PCV vaccine. ⋯ All measures demonstrated a significant difference in pain scores between the more painful (PCV) and less painful (DPTaP-Hib) vaccine for scores obtained after a single viewing. The majority of raters (4 out of 5) preferred the MBPS. Together, these results provide preliminary support for the MBPS as the primary outcome of pain during vaccine injections in infants.