Safety of the trivalent inactivated influenza vaccine among children: a population-based study.
ABSTRACT To our knowledge, there are no published population-based studies on the safety of the inactivated trivalent influenza vaccine among children.
To screen a large population of children for evidence of increased medical visits in the 2 weeks after influenza vaccination compared with 2 control periods. Secondary analyses included shorter risk periods and restricted age categories.
Self-control screening analysis. Children vaccinated from January 1, 1993, through December 31, 1999, were randomly divided into 2 equal groups. In group 1, risks of outpatient, emergency department, and inpatient visits during the 14 days after vaccination were compared with the risks of visits in 2 control periods. Significant plausible medically attended events identified in group 1 were then analyzed in group 2, using the same 2 control periods. Medically attended events significant in both groups were considered potentially associated with vaccination and were assessed by medical record review.
Five managed care organizations in the United States.
Children younger than 18 years who received an influenza vaccination in one of the managed care settings (N = 251 600).
Among vaccinated children seen for a medically attended event, the odds of the visit occurring in the 2 weeks after vaccination vs during 1 of the 2 control periods.
Study participants incurred 1165, 230, and 489 different diagnoses during the 14 days after vaccination according to the outpatient, emergency department, and inpatient data, respectively. Four diagnoses were positively associated with the vaccine in both groups 1 and 2: impetigo, dermatitis, uncomplicated diabetes mellitus, and ureteral disorder not otherwise specified. After medical record review, impetigo (9 cases) in children 6 to 23 months old remained significantly associated with vaccination.
This large screening safety study did not reveal any evidence of important medically attended events associated with pediatric influenza vaccination.
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ABSTRACT: Introduction: Influenza illness is an important public health problem and annual vaccination is globally recommended for high risk populations. Objective: The aim was to evaluate and compare the effectiveness of influenza vaccines in reducing hospitalizations for influenza or pneumonia during two influenza seasons in the elderly. Methods: A case-control study was performed, using administrative database of the Local Health Unit Roma-A (LHU RM-A). The included subjects were at least 65 years old and residing in one of the four districts of the LHU. The cases were hospitalized for influenza or pneumonia during influenza season in the years 2010-2011 and 2011-2012. The controls were hospitalized in the same period, but not for influenza or pneumonia. The subjects were immunized with the trivalent inactivated influenza vaccine (TIV) in the first influenza season (2010-2011) and with the adjuvanted influenza vaccine MF59 (ATIV) in the second season (2011-2012). Results: A total of 269 cases and 1247 controls were included for the 2010-2011 influenza season, and 365 cases and 1227 controls were selected for the 2011-2012 season. Up to 63.6% cases and 53.5% controls in the 2010-2011 season and 78.6% of cases and 64.1% of controls in the 2011-2012 season have not been vaccinated. Female gender and high educational level were protective factors for hospitalization. Subjects over 75 years were at high risk of hospitalization compared to 65-74 years olds. Influenza vaccination reduced significantly hospitalization in both seasons. In subjects with 65-74 years TIV was more effective than ATIV; vice versa for those over 75 years old. Discussion and conclusion: TIV and ATIV reduce hospitalization for influenza or pneumonia with a variable degree of protection in different age groups. In particular, ATIV is more effective in individuals over 75 years old.Vaccine 07/2014; 32(41). DOI:10.1016/j.vaccine.2014.07.077 · 3.49 Impact Factor
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ABSTRACT: Large healthcare databases maintained by health plans have been widely used to conduct customized protocol-based epidemiological safety studies as well as targeted routine sequential monitoring of suspected adverse events for newly licensed vaccines. These databases also offer a rich data source to discover vaccine-related adverse events not known prior to licensure using data mining methods, but they remain relatively under-utilized for this purpose. Initial safety applications of data mining methods using ‘big healthcare data’ are promising, but stronger integration of database expertize, epidemiological design, and statistical analysis strategies are needed to better leverage the available information, reduce bias, and improve reporting transparency. We enumerate major methodological challenges in mining large healthcare databases for vaccine safety research, describe existing strategies that have been used to address these issues, and identify opportunities for methodological advancements that emphasize the importance of adapting techniques used in customized protocol-based vaccine safety assessments. Investment in such research methods and in the development of deeper collaborations between database safety experts and data mining methodologists has great potential to improve existing safety surveillance programs and further increase public confidence in the safety of newly licensed vaccines.Statistical Analysis and Data Mining 10/2014; 7(5). DOI:10.1002/sam.11232
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ABSTRACT: The Vaccine Safety Datalink (VSD) is a collaborative project between the Centers for Disease Control and Prevention (CDC) and 9 health care organizations. Established in 1990, VSD is a vital resource informing policy makers and the public about the safety of vaccines used in the United States. Large linked databases are used to identify and evaluate adverse events in over 9 million individuals annually. VSD generates rapid, important safety assessments for both routine vaccinations and emergency vaccination campaigns. VSD monitors safety of seasonal influenza vaccines in near-real time, and provided essential information on the safety of monovalent H1N1 vaccine during the 2009 pandemic. VSD investigators have published important studies demonstrating that childhood vaccines are not associated with autism or other developmental disabilities. VSD prioritizes evaluation of new vaccines; searches for possible unusual health events after vaccination; monitors vaccine safety in pregnant women; and has pioneered development of biostatistical research methods.Vaccine 08/2014; 32(42). DOI:10.1016/j.vaccine.2014.07.073 · 3.49 Impact Factor