Doses Of Influenza Vaccine Research Articles

Investigating adverse events following immunisation with pneumococcal polysaccharide vaccine using electronic General Practice data

BackgroundIn early 2011, following an increased number of reports of severe vaccine-related injection site reactions, Australian authorities recommended against administering repeat doses of the 23-valent pneumococcal polysaccharide vaccine (23vPPV) in otherwise healthy adults. The aim of this study was to assess a source of electronic medical record data from primary care providers (General Practitioners, GPs), for validity and ability to retrospectively detect this adverse event signal. MethodsThe General Practice Research Network (GPRN) holds data routinely collected from a representative sample of Australian GPs. Data were extracted on persons 18years or older who had received at least one dose of 23vPPV or influenza vaccine (as comparator) between January 2002 and June 2012. Increases above background levels were assessed using 95% confidence intervals of reaction rates, calculated from the Poisson distribution of counts. ResultsThere was an average of 253 practices and 532 GPs contributing data per year. Over the study period there were 95,760 recorded 23vPPV administrations and 823 reactions, of which 233 were local. For influenza vaccine the numbers were 683,829 doses, 3001 and 387 respectively. Patterns of vaccinations and reactions were consistent with known safety profiles. There were 3 local reactions following 23vPPV in early 2011 (235/100,000 doses, 95% CI 49–717), which was not significantly different to the historical average (260, 225–298). We estimate that this system could have detected a 3-fold increase over background levels. ConclusionsUsing GP consultation data, we were unable to confirm an increase in local reactions detected by passive surveillance, suggesting that this apparent signal was artefactual. GP consultation data captures large numbers of vaccine recipients and medically attended adverse reactions at low cost. If available in a timely manner and expanded, this system has significant potential for use in validation of apparent signals from passive surveillance.

Two-dose seasonal influenza vaccine coverage and timeliness among children aged 6 months through 3 years: An evidence from the 2010–11 to the 2014–15 seasons in Zhejiang province, east China

ABSTRACTObjective: To evaluate the coverage and timeliness of seasonal influenza vaccine vaccination (SIV) among children aged 6 months to 3 years from the 2010–11 through the 2014–15 seasons. Methods: Children registered in Zhejiang Provincial Immunization Information System (ZJIIS) and needed 2 seasonal influenza vaccine doses in a given season from 2010–11 to 2014–15 were enrolled. Socio-economic information and SIV records of target children were extracted from ZJIIS on 1 January 2016. Any (≥1 dose) and full (2 doses) vaccination coverage by December 1 and March 31 as well as interval between 2 doses were calculated. Trends of coverage over time and determinants on fully vaccination coverage and interval between 2 doses were assessed. Results: Full SIV overage by Mar 31 increased from the 2010–11 to the 2014–15 seasons (2.60% vs 2.92%). Less than 1% of children received 2 doses by December 1. The interval between 2 doses among fully vaccinated children decreased over time (2010–11: 68.32 days; 2014–15: 49.51 days; p < 0.05). Age, socio-economic development level of resident areas were inversely associated with full vaccination coverage and resident children had a significantly higher full vaccination coverage. Younger age, resident children, receiving vaccination from higher service frequency clinics and clinics with morning and afternoon sessions were positive determinants of a shorter interval between 2 doses. Conclusion: Majority of children aged 6 months to 3 years remained at risk of incomplete and delayed SIV. The importance of the 2-dose SIV recommendation needs to be emphasized and effective interventions needs to be implemented to improve the completeness and the timeliness of SIV.

Influenza Vaccine Effectiveness in the United States During the 2016–2017 Season

BackgroundEach year, the US Influenza Vaccine Effectiveness Network estimates the effectiveness of seasonal influenza vaccine to prevent influenza-associated, medically attended acute respiratory illness.MethodsPatients aged ≥6 months seeking outpatient medical care for an acute respiratory illness within 7 days of illness onset were enrolled in 5 study locations during the 2016–17 influenza season. Specimens were collected and tested for influenza by RT-PCR. Patients were considered vaccinated if they received ≥1 dose of any seasonal influenza vaccine ≥14 days before illness onset, according to medical records, immunization registries and self-report. Interim vaccine effectiveness (VE) estimates were calculated as 100% x (1 – adjusted odds ratio) from multivariable logistic regression models comparing odds of vaccination among influenza-positive vs. influenza test-negative patients.ResultsFrom November 28, 2016—April 14, 2017, 7,410 patients were enrolled; 2,073 (28%) tested influenza-positive, including 1,419 (68%) influenza A (1,364 [96%] A/H3N2) and 649 (31%) influenza B viruses. Interim overall adjusted VE was 43% (95% confidence interval [CI], 37–49) against medically attended illness due to any influenza virus; interim VE estimates were 38% (95% CI, 29–45) against A/H3N2 and 54% (95% CI, 45–62) against any influenza B virus. Antigenic characterization indicated that circulating viruses remained similar to vaccine strains.ConclusionPreliminary results for the 2016–17 season showed significant protection against medically attended influenza due primarily to A/H3N2 and B viruses. Preliminary results for A/H3N2 and B viruses were consistent with previous seasons in which circulating viruses were antigenically similar to vaccine strains. Final results are pending.Disclosures A. S. Monto, sanofi pasteur: Grant Investigator, Research grant; Novartis: Consultant, Consulting fee; Protein Sciences: Consultant, Consulting fee; E. T. Martin, Merck: Grant Investigator, Research grant; Roche: Grant Investigator, Research grant; E. Belongia, MedImmune: Grant Investigator, Research support; H. Q. Mclean, MedImmune: Grant Investigator, Research grant; M. Gaglani, MedImmune: Grant Investigator, Research grant; R. Zimmerman, Merck: Grant Investigator, Research grant; sanofi pasteur: Grant Investigator, Research grant; Pfizer: Grant Investigator, Research grant; M. P. Nowalk, Merck: Grant Investigator, Research grant; L. A. Jackson, Novavax: Grant Investigator, Research grant

Efficacy and Effectiveness of High-Dose Influenza Vaccine for Older Adults: A Systematic Review and Meta-Analysis

BackgroundSeasonal influenza epidemics are responsible for significant disease burden each year, especially in adults over the age of 65. Only recently have there been vaccines that are formulated specifically for individuals 65 years of age or older, one of which, Fluzone®High-Dose (IIV3-HD), has received widespread use in the US. This study aims to review the evidence of efficacy and effectiveness of IIV3-HD compared with standard dose influenza vaccine (IIV3) in individuals aged 65 years or older against clinical outcomes plausibly related to influenza.MethodsA systematic review of four electronic databases and other sources was conducted for randomized and observational studies assessing vaccine efficacy or effectiveness (VE) of IIV3-HD against clinical outcomes such as influenza-like illness, hospital admissions and death in adults 65 years of age or older. A meta-analysis was conducted by separately extracting individual VEs reported in the studies and estimating random-effects pooled efficacy against each of the clinical outcomes.Results7 eligible studies (4 randomized trials and 3 observational studies) were identified following the screening of 1,816 studies. All of these studies reported relative VE (rVE) of IIV3-HD vs. IIV3, and not absolute efficacy/effectiveness of IIV3-HD. Of those, 5 studies reported rVE for IIV3-HD vs. IIV3 against influenza-like illness, 6 studies reported rVE against hospital admissions, and 3 studies reported rVE against death. IIV3-HD demonstrated improved protection against influenza-like illness (rVE=18.3%, 95% CI: 7.0 to 28.3%), and was also more effective at preventing hospital admissions due to influenza illness (rVE=19.4%, 95% CI: 6.7 to 30.4%), pneumonia (rVE=22.4%, 95% CI: 5.0 to 36.5%), cardiorespiratory events (rVE=12.0%, 95% CI: 4.9 to 18.6%), and death following a hospital admission for influenza (rVE=22.2%, 95% CI: -18.2 to 48.8%). IIV3 also had a modest but not statistically significant impact on all-cause hospital admissions (rVE= 7.3%, 95% CI: -1.5 to 15.4%) and all-cause death (rVE=0.8%, 95% CI: -4.2 to 5.5%).ConclusionThere is significant evidence demonstrating IIV3-HD is more effective than standard dose influenza vaccine at reducing the clinical outcomes typically associated with influenza infection in older adults.This study was funded by sanofi pasteur.Disclosures J. Lee, sanofi pasteur: Employee, Salary; G. Lam, sanofi pasteur: Employee, Salary; T. Shin, sanofi pasteur: Employee, Salary; J. Kim, sanofi pasteur: Co-op Student, Educational support; A. Krishnan, sanofi pasteur: Co-op Student, Educational support; B. Seet, sanofi pasteur: Employee and Shareholder, Salary; D. Neame, sanofi pasteur: Employee and Shareholder, Salary; D. P. Greenberg, sanofi pasteur: Employee and Shareholder, Salary; A. Chit, sanofi pasteur: Employee, Salary

Parental-Reported Full Influenza Vaccination Coverage of Children in the U.S.

Depending upon influenza vaccination history, children aged 6 months-8 years need one or two doses of influenza vaccine to be considered fully vaccinated. The objectives of this study were to quantify the percentage of children aged 6 months-8 years who were fully vaccinated against influenza based on parental report, overall, by state, and by sociodemographic characteristics, and to examine sociodemographic characteristics associated with being fully vaccinated. Data from the National Immunization Survey-Flu for the 2012-2013 and 2013-2014 influenza seasons were analyzed in 2015 using the Kaplan-Meier method to produce vaccination coverage estimates. Wald chi-square tests were used to test for bivariate associations, and Cox proportional hazards models were used to test for demographic characteristics independently associated with the child being fully vaccinated. The percentages of children aged 6 months-8 years who were fully vaccinated during the 2012-2013 and 2013-2014 influenza seasons were 41.0% and 45.2%, respectively. Full vaccination varied widely by state and was more likely for children requiring only one dose. Based on the statistical models, children likely to be fully vaccinated were older, non-black, had a mother with an education >12 years, or lived in a high-income household. Most children in the U.S. are not fully vaccinated against influenza. Reminder systems and interventions that reduce or remove barriers to children receiving their second doses of influenza vaccine may improve full influenza vaccination coverage among all children.

Greater activation of peripheral T follicular helper cells following high dose influenza vaccine in older adults forecasts seroconversion

BackgroundInfluenza related morbidity and mortality disproportionately impacts older adults. The serologic response to vaccine is diminished in older adults; however, high dose inactivated influenza vaccine (HD IIV) has shown improved rates of seroconversion compared to standard dose (SD IIV). We hypothesize this may be due to the superior ability of high dose vaccine to activate T follicular helper (Tfh) cells and provide B cell dependent T cell help. MethodsWe measured peripheral Tfh (pTfh) activation in 50 community dwelling adults 65years or older who were randomly assigned to receive either the HD IIV or SD IIV. ResultsThe HD vaccination elicited significantly higher levels of ICOS expression on pTfh cells, at day 7 compared to SD vaccination (p=0.02). The magnitude of the increase in ICOS+ pTfh cells from baseline to day 7 was predictive of seroconversion for both influenza A and B vaccination. ConclusionStrong Tfh activation in response to influenza vaccination forecasts successful seroconversion in older adults, and HD IIV elicits greater Tfh activation than SD IIV. Future vaccine studies should focus on ways to further optimize the Tfh response.

Influenza-Like Illness Diagnosis and Management in the Acute Care Setting.

During influenza season, acute respiratory illness due to influenza is difficult to distinguish from other influenza-like illnesses, but testing should be reserved for situations when timely results will influence management or infection control measures. Immunization status and timing of disease onset notwithstanding, a neuraminidase inhibitor should be offered immediately for certain high-risk children; neuraminidase inhibitor treatment should be considered if shorter illness is warranted or an at-risk sibling may be protected. Antipyretics and cough control may be useful. Immunization with an age-appropriate dose of an inactivated influenza vaccine is the cornerstone of prevention for health care personnel and our patients.

Immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine: a Phase III, open-label study of adults in Brazil

The World Health Organization influenza forecast now includes an influenza B strain from each of the influenza B lineages (B/Yamagata and B/Victoria) for inclusion in seasonal influenza vaccines. Traditional trivalent influenza vaccines include an influenza B strain from one lineage, but because two influenza B lineages frequently co-circulate, the effectiveness of trivalent vaccines may be reduced in seasons of influenza B vaccine-mismatch. Thus, quadrivalent vaccines may potentially reduce the burden of influenza compared with trivalent vaccines.In this Phase III, open-label study, we assessed the immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine (Fluarix™ Tetra) in Brazilian adults (NCT02369341). The primary objective was to assess hemagglutination-inhibition antibody responses against each vaccine strain 21 days after vaccination in adults (aged ≥18–60 years) and older adults (aged >60 years). Solicited adverse events for four days post-vaccination, and unsolicited adverse events and serious adverse events for 21 days post-vaccination were also assessed.A total of 63 adults and 57 older adults received one dose of inactivated quadrivalent influenza vaccine at the beginning of the 2015 Southern Hemisphere influenza season. After vaccination, in adults and older adults, the hemagglutination-inhibition titers fulfilled the European licensure criteria for immunogenicity. In adults, the seroprotection rates with HI titer ≥1:40 were 100% (A/H1N1), 98.4% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria); in older adults were 94.7% (A/H1N1), 96.5% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria). Pain was the most common solicited local adverse events in adults (27/62) and in older adults (13/57), and the most common solicited general adverse events in adults was myalgia (9/62), and in older adults were myalgia and arthralgia (both 2/57). Unsolicited adverse events were reported by 11/63 adults and 10/57 older adults.The study showed that inactivated quadrivalent influenza vaccine was immunogenic and well-tolerated in Brazilian adults and older adults.

Seasonal influenza vaccination in China: Landscape of diverse regional reimbursement policy, and budget impact analysis

BackgroundTo explore the current landscape of seasonal influenza vaccination across China, and estimate the budget of implementing a national “free-at-the-point-of-care” vaccination program for priority populations recommended by the World Health Organization. MethodsIn 2014 and 2016, we conducted a survey across provincial Centers for Disease Control and Prevention to collect information on regional reimbursement policies for influenza vaccination, estimated the national uptake using distributed doses of influenza vaccines, and evaluated the budget using population size and vaccine cost obtained from official websites and literatures. ResultsRegular reimbursement policies for influenza vaccination are available in 61 mutually exclusive regions, comprising 8 provinces, 45 prefectures, and 8 counties, which were reimbursed by the local Government Financial Department or Basic Social Medical Insurance (BSMI). Finance-reimbursed vaccination was offered mainly for the elderly, and school children for free in Beijing, Dongli district in Tianjin, Karamay, Shenzhen and Xinxiang cities. BSMI-reimbursement policies were limited to specific medical insurance beneficiaries with distinct differences in the reimbursement fractions. The average national vaccination coverage was just 1.5–2.2% between 2004 and 2014. A free national vaccination program for priority populations (n=416million), would cost government US$ 757million (95% CI 726–789) annually (uptake rate=20%). ConclusionsAn increasing number of regional governments have begun to pay, partially or fully, for influenza vaccination for selected groups. However, this small-scale policy approach has failed to increase national uptake. A free, nationwide vaccination program would require a substantial annual investment. A cost-effectiveness analysis is needed to identify the most efficient methods to improve coverage.

Trends in compliance with two-dose influenza vaccine recommendations in children aged 6 months through 8 years, 2010–2015

BackgroundChildren aged 6 months through 8 years may require two doses of influenza vaccine for adequate immune response against the disease. However, poor two-dose compliance has been reported in the literature. MethodsWe analyzed data for >2.6million children from six immunization information system (IIS) sentinel sites, and assessed full vaccination coverage and two-dose compliance in the 2010–2015 influenza vaccination seasons. Full vaccination was defined as having received at least the recommended number of influenza vaccine doses (one or two), based on recommendations from the Advisory Committee on Immunization Practices. Two-dose compliance was defined as the percentage of children during each season who received at least two doses of influenza vaccine among those who required two doses and initiated the series. ResultsAcross seasons, ⩾1-dose influenza vaccination coverage was mainly unchanged among 6–23montholds (range: 60.9–66.6%), 2–4yearolds (range: 44.8–47.4%), and 5–8yearolds (range: 34.5–38.9%). However, full vaccination coverage showed increasing trends from 2010–11 season to 2014–15 season (6–23months: 43.0–46.5%; 2–4yearolds: 26.3–39.7%; 5–8yearolds, 18.5–33.9%). Across seasons, two-dose compliance remained modest in children 6–23months (range: 63.3–67.6%) and very low in older children (range: 11.6–18.7% in children 2–4yearsand6.8–13.3% in children 5–8years). In the 2014–15 season, among children who required and received 2 doses, only half completed the two-dose series before influenza activity peaked. ConclusionsImproved messaging of the two-dose influenza vaccine recommendations is needed for providers and parents. Providers are encouraged to determine a child’s eligibility for two doses of influenza vaccine using the child’s vaccination history, and to vaccinate children early in the season so that two-dose series are completed before influenza peaks.

A phase 1, open-label, randomized study to compare the immunogenicity and safety of different administration routes and doses of virosomal influenza vaccine in elderly

BackgroundInfluenza remains a significant problem in elderly despite widespread vaccination coverage. This randomized, phase-I study in elderly compared different strategies of improving vaccine immunogenicity. MethodsA total of 370 healthy participants (⩾65years) were randomized equally 1:1:1:1:1:1 to six influenza vaccine treatments (approximately 60–63 participants per treatment arm) at day 1 that consisted of three investigational virosomal vaccine formulations at doses of 7.5, 15, and 45μg HA antigen/strain administered intradermally (ID) by MicronJet600™ microneedle device (NanoPass Technologies) or intramuscularly (IM), and three comparator registered seasonal vaccines; Inflexal V™ (Janssen) and MF59 adjuvanted Fluad™ (Novartis) administered IM and Intanza™ (Sanofi Pasteur) administered ID via Soluvia™ prefilled microinjection system (BD). Serological evaluations were performed at days 22 and 90 and safety followed-up for 6months. ResultsIntradermal delivery of virosomal vaccine using MicronJet600™ resulted in significantly higher immunogenicity than the equivalent dose of virosomal Inflexal V™ administered intramuscularly across most of the parameters and strains, as well as in some of the readouts and strains as compared with the 45μg dose of virosomal vaccine formulation. Of 370 participants, 300 (81.1%) reported ⩾1 adverse event (AE); more participants reported solicited local AEs (72.2%) than solicited systemic AEs (12.2%). ConclusionsIntradermal delivery significantly improved influenza vaccine immunogenicity compared with intramuscular delivery. Triple dose (45μg) virosomal vaccine did not demonstrate any benefit on vaccine’s immunogenicity over 15μg commercial presentation. All treatments were generally safe and well-tolerated.

Assessing vaccine safety within Ontario's Universal Influenza Immunization Program, 2012-2013 to 2014-2015.

Influenza vaccine is recommended to prevent influenza-related morbidity and mortality. Post-marketing surveillance of adverse events following influenza vaccine is essential to monitor vaccine safety, inform immunization program planning and evaluation, and build confidence in immunization. To summarize adverse events following immunization (AEFIs) reported after receipt of influenza vaccines administered within the Universal Influenza Immunization Program in Ontario. AEFIs following administration of influenza vaccines between September 1, 2012 and August 31, 2015 were extracted from the Integrated Public Health Information System (iPHIS) on September 1, 2015. Events were grouped by provincial surveillance definitions. Reporting rates were calculated using provincial population estimates or net doses distributed as the denominator. The standard World Health Organization definition of serious AEFIs was used. There were 12.1 million doses of influenza vaccine distributed in Ontario and 528 AEFIs reported following influenza vaccines administered over three seasons. The annualized reporting rate was 4.4 per 100,000 doses distributed with a significant decreasing trend over time (p<0.05). The median age was 39.6 years (range six months-96 years); children under four years of age had the highest reporting rate (3.5 per 100,000 population). Disproportionate reporting among females was observed (76.5 percent), most notably in those 18 years and older. The most frequently reported events were injection site reactions (36.2 percent of reports). Others included allergic skin reactions (21.1 percent) and rashes (17.3 percent). Serious AEFIs were rare with a reporting rate of 1.6 per million doses distributed. This assessment found a low rate of reported adverse events following influenza vaccines administered in Ontario. Most reported events were mild and resolved completely. The findings were consistent with the very good safety profile of influenza vaccines.

Comparison of hemagglutination inhibition and microbead array assays for the measurement of influenza antibody levels in HIV-infected adults

IntroductionDetermining vaccine responsiveness is challenging in immune compromised individuals. The microbead array (MBA) assay is a rapid, inexpensive test for evaluating influenza vaccine immunogenicity. MBA performance was compared to hemagglutination inhibition assay (HAI) utilizing HIV seropositive vaccine recipient specimens. MethodsCTN 253 evaluated standard dose, single antigen, inactivated split adjuvanted (AS03(A)) H1N1 influenza vaccine (Arepanrix) vs standard dose plus booster. CTN237 evaluated three doses of a seasonal, trivalent killed split non-adjuvanted influenza vaccine (Fluviral). Samples of convenience from 75 CTN 253 and 58 CTN 237 participants were evaluated by MBA and HAI. MBA seroreactivity cut-offs of 500 and 1000 mean fluorescent intensity were used to compare those derived by HAI [titer ≥40 (seroprotection) and 4-fold titer increase from baseline (seroconversion)]. ResultsCTN253: Using a MBA cut-off of 500, 75% and 59% had seroreactive titers at visit 2 and 78% and 61% at visit 3 for the single versus double dose study arms. Many participants were categorized differently by the HAI and MBA tests, with raw agreement of 59% at visit 2 and 57% at visit 3. CTN 237: Baseline MBA medians (IQR) were 803 (12-2626) for the A/Brisbane strain and 460 (14-1758) for the B/Florida strain. Using a cut-off of 500 yielded for the A/Brisbane strain seroreactivity rates of 44%, 58%, and 63% were observed for the three doses of vaccine tested. The raw agreement was 47%. B/Florida strain analyses yielded similar results. For all strains assessed in both studies, no relationship between MBA values and baseline variables was identified. ConclusionThe concordance of results between the MBA assay and the HAI assay is very low. MBA assay may be more sensitive than the HAI assay suggesting that it was either detecting more false-positive results and/or that the HAI assay had more false negative.

Cellular and humoral influenza-specific immune response upon vaccination in patients with common variable immunodeficiency and unclassified antibody deficiency

BackgroundImmunization against seasonal influenza with inactivated vaccine is recommended for patients with common variable immunodeficiency (CVID). However, humoral vaccine response in CVID patients is frequently impaired and current knowledge on T cell vaccine response in CVID and other patients with antibody deficiency is poor. ObjectiveIn the present study, we comparatively analyzed the antibody and T cellular immune response of patients with CVID and unclassified antibody deficiency to influenza vaccination in the season 2013–2014. MethodsEight patients with CVID, 8 patients with unclassified antibody deficiency and 9 healthy controls were vaccinated with a single dose of non-adjuvanted seasonal influenza vaccine. Before and 3 weeks after the vaccination antibody titers against the strains A/California/7/2009, A/Texas/50/2012, and B/Massachusetts/02/2012 included in the vaccine were measured by hemagglutination inhibition testing. Additionally, vaccine-specific T cell cytokine response was determined by stimulation with the complete vaccine in vitro. ResultsWhereas all healthy controls responded to vaccination with serum antibody titers, only 1/8 CVID patients and 4/8 patients with unclassified antibody deficiency showed a response against at least 1 of the 3 vaccine strains. However, 7/8 of the CVID and 6/8 of the patients with unclassified antibody deficiency had similar frequencies of vaccine-induced IFN-γ, TNF-α and IL-2 producing CD40L+ T cells as the control group. ConclusionOur data suggest that most CVID and unclassified antibody deficiency patients benefit from seasonal influenza vaccination by mounting a cellular response.

Complete Influenza Vaccination Trends for Children Six to Twenty-Three Months.

Prevention of influenza among infants and young children is a public health priority because of their high risk for influenza-related complications. Depending on a child's age and previous influenza vaccination history, they are recommended to receive either 1 dose or 2 doses of influenza vaccine to be considered fully vaccinated against influenza for the season. We compared estimates of full (complete) influenza vaccination coverage of children 6 to 23 months across 10 consecutive influenza seasons (2002-2012), by race/ethnicity, age group, and by number of doses required to be fully vaccinated given child's vaccination history. National Immunization Survey data were used to estimate full influenza vaccination status among children 6 to 23 months on the basis of provider report. Estimates were computed by using Kaplan-Meier survival analysis methods. Full influenza vaccination coverage among children 6 to 23 months increased from 4.8% in the 2002-2003 influenza season to 44.7% in the 2011-2012 season. In all 10 influenza seasons studied, non-Hispanic black children and Hispanic children had lower full influenza vaccination coverage than non-Hispanic white children. For all 10 influenza seasons, full influenza vaccination coverage was higher among children requiring only 1 dose compared with those requiring 2 doses. Less than half of children 6 to 23 months in the United States, and an even a smaller percentage of Hispanic and non-Hispanic black children, are fully vaccinated against influenza. More implementation of evidence-based strategies that increase the percentage of children who are fully vaccinated is needed.

Comparing High Dose vs. Standard Dose Influenza Vaccine Efficacy in Flu Prevention within the Elderly Population in Acute Care and Long-Term Care

Comparing High Dose vs. Standard Dose Influenza Vaccine Efficacy in Flu Prevention within the Elderly Population in Acute Care and Long-Term Care

Tolerability of 2 doses of pandemic influenza vaccine (Focetria®) and of a prior dose of seasonal 2009-2010 influenza vaccination in the Netherlands

ABSTRACTIn the Netherlands, people indicated for seasonal influenza vaccination are divided in 3 risk groups, i.e. those less than 60 y (y) with comorbidity and those 60 y and over with and without comorbidity. Those risk groups were also eligible for pandemic vaccination during the 2009 influenza A(H1N1) pandemic.We assessed tolerability of seasonal influenza vaccination and 2 doses of pandemic influenza A(H1N1) vaccine, adjuvanted with MF-59, administered 2 and 5 weeks after seasonal 2009–2010 vaccination among adults.Vaccinees were asked to return questionnaires on local and systemic adverse events (AEs) after each of 3 consecutive vaccinations given at the office of their General Practitioner. Sex- and risk group-specific AE-frequencies were calculated. Generalized Linear Mixed Model with seasonal vaccination as reference was used to calculate odds ratios (ORs) for AEs of the 2 pandemic doses.5553 questionnaires (3251 vaccinees) were returned. Vaccinees reported any local AE after seasonal vaccination and both pandemic doses in 34%, 23%, and 18%, respectively. These percentages were 29%, 25%, and 16% for any systemic AE. Men reported fewer local and systemic AEs then women (p<0.0001). The risk of local (OR range 0.34-0.63) and systemic (OR range 0.39–0.99) AEs (overall, stratified by risk group and by sex) was lower after both pandemic doses compared to seasonal vaccination. This decreased risk was more pronounced after the second pandemic dose than after the first.Therefore, we conclude that MF59-adjuvanted pandemic vaccine given after seasonal vaccination was well tolerated.

Effect of influenza vaccination on the prognosis of hospitalized influenza patients

ABSTRACTObjectives: This study aimed to assess whether influenza vaccination reduces the risk of severe and fatal outcomes in influenza inpatients aged ≥65 years.Methods: During the 2013–2014 influenza season persons aged ≥65 years hospitalized with laboratory-confirmed influenza were selected in 19 Spanish hospitals. A severe influenza case was defined as admission to the intensive care unit, death in hospital or within 30 days after admission. Logistic regression was used to compare the influenza vaccination status between severe and non-severe influenza inpatients.Results: Of 433 influenza confirmed patients, 81 (19%) were severe cases. Vaccination reduced the risk of severe illness (odds ratio: 0.57; 95%CI: 0.33–0.98). The cumulative number of influenza vaccine doses received since the 2010–2011 season was associated with a lower risk of severe influenza (odds ratio: 0.78; 95% CI 0.66–0.91).Conclusion: Adherence to seasonal influenza vaccination in the elderly may reduce the risk of severe influenza outcomes.

The Modification Effect of Influenza Vaccine on Prognostic Indicators for Cardiovascular Events after Acute Coronary Syndrome: Observations from an Influenza Vaccination Trial.

Introduction. The prognosis of acute coronary syndrome (ACS) patients has been improved with several treatments such as antithrombotics, beta-blockers, and angiotensin-converting enzyme inhibitors (ACEI) as well as coronary revascularization. Influenza vaccination has been shown to reduce adverse outcomes in ACS, but no information exists regarding the interaction of other treatments. Methods. This study included 439 ACS patients from Phrommintikul et al. A single dose of inactivated influenza vaccine was given by intramuscular injection in the vaccination group. The cardiovascular outcomes were described as major cardiovascular events (MACEs) which included mortality, hospitalization due to ACS, and hospitalization due to heart failure (HF). The stratified and multivariable Cox's regression analysis was performed. Results. The stratified Cox's analysis by influenza vaccination for each cardiovascular outcome and discrimination of hazard ratios showed that beta-blockers had an interaction with influenza vaccination. Moreover, the multivariable hazard ratios disclosed that influenza vaccine is associated with a significant reduction of hospitalization due to HF in patients who received beta-blockers (HR = 0.05, 95% CI = 0.004–0.71, P = 0.027), after being adjusted for prognostic indicators (sex, dyslipidemia, serum creatinine, and left ventricular ejection fraction). Conclusions. The influenza vaccine was shown to significantly modify the effect of beta-blockers in ACS patients and to reduce the hospitalization due to HF. However, further study of a larger population and benefits to HF patients should be investigated.

Commentary on: “Seasonal influenza vaccine dose distribution in 195 countries (2004–2013): Little progress in estimated global vaccination coverage”

Commentary on: “Seasonal influenza vaccine dose distribution in 195 countries (2004–2013): Little progress in estimated global vaccination coverage”