The antibody response to influenza vaccination is not impaired in type 2 diabetics

BackgroundDiabetics are considered to be at high risk for complications from influenza infection and type 2 diabetes is a significant comorbidity of obesity. Obesity is an independent risk factor for complications from infection with influenza. Annual vaccination is considered the best strategy for protecting against influenza infection and it's complications. Our previous study reported intact antibody responses 30 days post vaccination in an obese population. This study was designed to determine the antibody response to influenza vaccination in type 2 diabetics.MethodsSubjects enrolled were 18 or older without immunosuppressive diseases or taking immunosuppressive medications. A pre-vaccination blood draw was taken at time of enrollment, the subjects received the influenza vaccine and returned 28–32 days later for a post-vaccination blood draw. Height and weight were also obtained at the first visit and BMI was calculated. Antibody levels to the vaccine were determined by both ELISA and hemagglutination inhibition (HAI) assays.ResultsAs reported in our previous work, obesity positively correlates with the influenza antibody response (p = 0.02), while age was negatively correlated with antibody response (p < 0.001). In both year 1 and year 2 of our study there was no significant difference in the percentage of the type 2 diabetic subjects classified as seroprotected or a responder to the influenza vaccine compared to the non-diabetic subjects.ConclusionsThese data are important because they demonstrate that diabetics, considered a high risk group during influenza season, are able to mount an antibody response to influenza vaccination that may protect them from influenza infection.     

Cross-sectional survey: Risk-averse French general practitioners are more favorable toward influenza vaccination

ObjectivesWe tested the following hypotheses: (i) risk-averse general practitioners (GPs) are more likely to be vaccinated against influenza; (ii) and risk-averse GPs recommend influenza vaccination more often to their patients. In risk-averse GPs, the perceived benefits of the vaccine and/or the perceived risks of the infectious disease might indeed outweigh the perceived risks of the vaccine.Patients/MethodsIn 2010–2012, we conducted a cross-sectional survey of a nationwide French representative sample of 1136 GPs. Multivariate analyses adjusted for four stratification variables (age, gender, urban/suburban/rural practice location and annual patient consultations) and for GPs’ characteristics (group/solo practice, and occasional practice of alternative medicine, e.g., homeopathy) looked for associations between their risk attitudes and self-reported vaccination behavior. Individual risk attitudes were expressed as a continuous variable, from 0 (risk-tolerant) to 10 (risk-averse).ResultsOverall, 69% of GPs reported that they were very favorable toward vaccination in general. Self-reported vaccination coverage was 78% for 2009/2010 seasonal influenza and 62% for A/H1N1 pandemic influenza. Most GPs (72%) reported recommending the pandemic influenza vaccination to at-risk young adults in 2009, but few than half (42%) to young adults not at risk. In multivariate analyses, risk-averse GPs were more often vaccinated against seasonal (marginal effect = 1.3%, P = 0.02) and pandemic influenza (marginal effect = 1.5%, P = 0.02). Risk-averse GPs recommended the pandemic influenza vaccination more often than their more risk-tolerant colleagues to patients without risk factors (marginal effect = 1.7%, P = 0.01), but not to their at-risk patients and were more favorable toward vaccination in general (marginal effect = 1.5%, P = 0.04).ConclusionIndividual risk attitudes may influence GPs’ practices regarding influenza vaccination, both for themselves and their patients. Our results suggest that risk-averse GPs may perceive the risks of influenza to outweigh the potential risks related to the vaccine.     

Factors associated with influenza vaccination in middle and older aged Australian adults according to eligibility for the national vaccination program

BackgroundIn Australia, influenza vaccination is recommended and provided free of charge for all adults aged ≥65 years and those aged <65 years with specific risk factors. Other than age, there is limited information on characteristics associated with vaccine uptake.MethodsWe used the 45 and Up Study, a large cohort of adults aged ≥45 years, who completed a questionnaire in 2012 asking about influenza vaccination. We compared characteristics of those reporting influenza vaccination in those aged <65 and ≥65 years using a log binomial model to estimate relative rates (RRs), adjusted for age and other factors.ResultsAmong 27,036 participants, the proportion reporting influenza vaccination in the last year increased steadily with age from 24.6% in those <54 years to 67.2% in those 75–79 years; of those eligible for universal free vaccine, (≥65 years) 57.3% had an influenza vaccination in the previous year. Many characteristics associated with higher vaccination rates in adults aged <65 years (mean 60.7) and those ≥65 years (mean 73.7) were similar. These included sex (women versus men: <65 years, aRR = 1.14[95% CI 1.08–1.20]; ≥65 years, aRR = 1.04[1.02–1.07]), higher BMI (≥30 kg/m² versus >18.5 to <25 kg/m²: <65 years, aRR = 1.16[1.09–1.24]; ≥65 years, aRR = 1.06[1.03–1.09]), requiring assistance with daily tasks versus not (<65 years, aRR = 1.27[1.15–1.40]; ≥65 years, aRR = 1.05[1.02–1.09]) and reporting versus not reporting specific chronic illnesses (<65 years, aRR = 1.55 [1.48–1.63]; ≥65 years, aRR = 1.08[1.06–1.10]). Current smokers had lower vaccination rates (<65 years, aRR = 0.78[0.69–0.90]; ≥65 years, aRR = 0.91[0.84–0.99]). Among those aged <65 years only, being a carer, higher income, and education were associated with influenza vaccination (aRR = 1.32[1.19–1.47], 1.17[1.10–1.24] and 1.12[1.10–1.22] respectively). Non-English speaking country of birth was associated with lower vaccination rates in ≥65 years (aRR 0.86[0.81–0.92]).ConclusionsFactors most strongly associated with vaccination were age and among those aged <65 years, having a medical indication recommended for influenza vaccination, suggesting higher uptake among those who can access free vaccine. Among those eligible for free vaccination, interventions could be targeted towards men, smokers, those from non-English speaking backgrounds and those <65 years with a medical indication.     

Influenza vaccine: Delayed vaccination schedules and missed opportunities in children under 2 years old

IntroductionIn Argentina respiratory disease is the third leading cause of death in children under 5 years. In 2011 influenza vaccination was included in the National Calendar for children between 6 and 24 months (two doses schedule). Influenza vaccine coverage for second dose was 46.1% in 2013. The aim was to determine the proportion of delayed schedules and missed opportunities, to assess the characteristics of missed opportunities for vaccination and to explore the perception of influenza disease and vaccination from the parents of children between 6 and 24 months in different regions of Argentina in 2013.MethodsAnalytical observational multicenter cross-sectional study. Structured surveys were carried out to the children's parents who were between 6 and 24 months of age during the influenza virus vaccination season (April–October 2013). Chi-Square test was used to assess association and differences between proportions and categorical variables. A logistic regression model was built to identify delay predictor variables in the vaccination schedules. Missed opportunities for vaccination were characterized through the estimation of proportions.Results1350 surveys were conducted in the three centers. We detected 65% (884/1340) of delayed influenza vaccination schedules, 97% of them associated with missed opportunities of vaccination. The independent protective factors associated with a decreases risk of delayed schedules were: (a) perception of the importance of influenza vaccination (OR = 0.42(0.18–0.94); p = 0.035), (b) having less than one year of age (OR = 0.75(0.59–0.96); p = 0.022), (c) to have received information in pediatric visits or in any media (OR = 0.71(0.56–0.90); p = 0.004). There was 38% of MOIV in 1st dose and 63.4% in 2nd dose. The main cause of MOIV in 1st dose was not detecting the need for vaccination (39%) and in 2nd dose the unknowledge of the vaccination schedule (35.3%). No cultural reasons were detected.ConclusionsHigh frequency of delayed vaccination schedules and missed opportunities were detected. Parents had little concern about the safety of influenza vaccine.     

Annual influenza vaccination reduces total hospitalization in patients with chronic hepatitis B virus infection: A population-based analysis

BackgroundThis study evaluated hospitalization and mortality in patients with chronic hepatitis B virus infection (HBV (+)) and matched comparison patients after stratifying the patients according to annual influenza vaccination (Vaccine (+)).MethodsData from Taiwan's National Health Insurance program from 2000 to 2009 were used to identify HBV(+)/vaccine(+) (n = 4434), HBV(+)/Vaccine(−) (n = 3646), HBV(−)/Vaccine(+) (n = 8868), and HBV(−)/Vaccine(−) (n = 8868) cohorts. The risk of pneumonia/influenza, respiratory failure, intensive care, hospitalization, and mortality in the four cohorts was evaluated.ResultsThe total hospitalization rate was significantly lower in patients with chronic HBV infection who received an annual influenza vaccination than in chronic HBV-infected patients who did not receive an influenza vaccination (16.29 vs. 24.02 per 100 person-years), contributing to an adjusted hazard ratio (HR) of 0.56 (95% confidence interval (CI) = 0.50–0.62). The HBV(+)/Vaccine(+) cohort also had lower risks than the HBV(+)/Vaccine(−) cohort for pneumonia and influenza (adjusted HR = 0.79, 95% CI = 0.67–0.92), intensive care unit admission (adjusted HR = 0.33, 95% CI = 0.25–0.43), and mortality (adjusted HR = 0.19, 95% CI = 0.15–0.24).ConclusionsOur results suggest that annual influenza vaccination can reduce the risk of hospitalization and mortality in patients with chronic HBV infection.     

Predictors of reported influenza vaccination in HIV-infected women in the United States, 2006–2007 and 2007–2008 seasons

ObjectiveTo estimate the cumulative incidence of self-reported influenza vaccination (“vaccination coverage”) and investigate predictors in HIV-infected women.MethodsIn an ongoing cohort study of HIV-infected women in five US cities, data from two influenza seasons (2006–2007 n = 1209 and 2007–2008 n = 1161) were used to estimate crude and adjusted prevalence ratios (aPR) and 95% confidence intervals ([,]) from Poisson regression with robust variance models using generalized estimating equations (GEE).ResultsIn our study, 55% and 57% of HIV-infected women reported vaccination during the 2006–2007 and 2007–2008 seasons, respectively. Using data from both seasons, older age, non-smoking status, CD4 T-lymphocyte (CD4) count ≥ 200 cells/mm³, and reporting at least one recent healthcare visit was associated with increased vaccination coverage. In the 2007–2008 season, a belief in the protection of the vaccine (aPR = 1.38 [1.18, 1.61]) and influenza vaccination in the previous season (aPR = 1.66 [1.44, 1.91]) most strongly predicted vaccination status.ConclusionInterventions to reach unvaccinated HIV-infected women should focus on changing beliefs about the effectiveness of influenza vaccination and target younger women, current smokers, those without recent healthcare visits, or a CD4 count < 200 cells/mm³.     

Parental perceptions of childhood seasonal influenza vaccination in Singapore: A cross-sectional survey

PurposeSeasonal influenza vaccination is recommended in children aged 6–59 months, but little is known about child vaccination coverage and determinants in Asian settings. We report the results of a survey of knowledge, attitudes, practices, and determinants of child influenza vaccination in Singapore.MethodsIn December 2015-March 2016, we conducted a survey of 332 parents of children aged 6 months to 5 years attending pre-schools. We assessed child influenza vaccine coverage and parental knowledge, attitudes, and practices of child influenza vaccination. We used multivariable regression and structural equation models to identify factors associated with child influenza vaccination.ResultsKnowledge about influenza, perceived benefit of vaccination, and willingness to vaccinate were high. However, only 32% of children had ever received influenza vaccine, and only 15% in the past year. Factors independently associated with child influenza vaccination included: being recommended influenza vaccine by a child’s doctor (prevalence ratio (PR) = 2.47, 95% CI: 1.75–3.48); receiving influenza vaccine information from a private general practitioner (PR = 1.47, 95% CI: 1.05–2.04); regularly receiving pre-travel influenza vaccine (PR = 1.64, 95% CI: 1.19–2.25); higher willingness to vaccinate (PR = 1.58, 95% CI:1.24–2.04 per unit increase in willingness score); and feeling well-informed about influenza vaccine (PR = 1.44, 95% CI: 1.04–1.99). Parents who obtained influenza vaccine information from television were less likely to have vaccinated their child (PR = 0.44, 95% CI: 0.23–0.85). Path analysis indicated that being recommended vaccination by a child's doctor increased willingness to vaccinate and self-efficacy (feeling well-informed about influenza vaccine). Median willingness-to-pay for a dose of influenza vaccine was SGD30 (interquartile range: SGD20-SGD50), and was higher in parents of vaccinated compared with unvaccinated children (SGD45 vs SGD30, p = 0.0012).ConclusionKnowledge and willingness to vaccinate was high in this parent population, but influenza vaccine uptake in children was low. Encouraging medical professionals to recommend vaccination of eligible children is key to improving uptake.     

Influenza during pregnancy: Incidence,vaccination coverage and attitudes toward vaccination in the French web-based cohort G-GrippeNet

IntroductionPregnancy is a risk factor for severe influenza. However, data on influenza incidence during pregnancy are scarce. Likewise, no data are available on influenza vaccine coverage in France since national recommendation in 2012. We aimed to assess these points using a novel nationwide web-based surveillance system, G-GrippeNet.MethodsDuring the 2014/2015 influenza season, pregnant women living in metropolitan France were enrolled through a web platform (https://www.grippenet.fr/). Throughout the season, participants were asked to report, on a weekly basis, if they had experienced symptoms of influenza-like-illness (ILI). ILI episodes reported were used to calculate incidence density rates based on period of participation from each participant. Vaccination coverage was estimated after weighing on age and education level from national data on pregnant women. Factors associated with higher vaccination coverage were obtained through a logistic regression with Odds Ratio (OR) corrected with the Zhang and Yu method.ResultsA total of 153 women were enrolled. ILI incidence density rate was 1.8 per 100 person-week (95%CI, 1.5–2.1). This rate was higher in women older than 40 years (RR = 3.0, 95%CI [1.1–8.3], p = 0.03) and during first/second trimesters compared to third trimester (RR = 4.0, 95%CI [1.4–12.0], p = 0.01). Crude vaccination coverage was 39% (95%CI, 31–47) and weighted vaccination coverage was estimated at 26% (95%CI, 20–34). Health care provider recommendation for vaccination (corrected OR = 7.8; 95%CI [3.0–17.1]) and non-smoking status (cOR = 2.1; 95%CI [1.2–6.9]) were associated with higher vaccine uptake.ConclusionThis original web based longitudinal surveillance study design proved feasible in pregnant women population. First results are of interest and underline that public health policies should emphasize the vaccination promotion through health care providers.     

Reasons for low influenza vaccination coverage among adults in Puerto Rico,influenza season 2013–2014

BackgroundInfluenza vaccination is recommended annually for all persons 6 months and older. Reports of increased influenza-related morbidity and mortality during the 2013–2014 influenza season raised concerns about low adult influenza immunization rates in Puerto Rico. In order to inform public health actions to increase vaccination rates, we surveyed adults in Puerto Rico regarding influenza vaccination-related attitudes and barriers.MethodsA random-digit-dialing telephone survey (50% landline: 50% cellphone) regarding influenza vaccination, attitudes, practices and barriers was conducted November 19–25, 2013 among adults in Puerto Rico. Survey results were weighted to reflect sampling design and adjustments for non-response.ResultsAmong 439 surveyed, 229 completed the survey with a 52% response rate. Respondents’ median age was 55 years; 18% reported receiving 2013–2014 influenza vaccination. Among 180 unvaccinated respondents, 38% reported barriers associated with limited access to vaccination, 24% reported they did not want or need influenza vaccination, and 20% reported safety concerns. Vaccinated respondents were more likely to know if they were recommended for influenza vaccination, to report greater perceived risk of influenza illness, and to report being less concerned about influenza vaccine safety (p-value < 0.05). Of the 175 respondents who saw a healthcare provider (HCP) since July 1, 2013, 38% reported their HCP recommended influenza vaccination and 17% were offered vaccination. Vaccination rates were higher among adults who received a recommendation and/or offer of influenza vaccination (43% vs. 14%; p-value < 0.01).ConclusionsFailure of HCP to recommend and/or offer influenza vaccination and patient attitudes (low perceived risk of influenza virus infection) may have contributed to low vaccination rates during the 2013–2014 season. HCP and public health practitioners should strongly recommend influenza vaccination and provide vaccinations during clinical encounters or refer patients for vaccination.     

Effects of prior influenza virus vaccination on maternal antibody responses: Implications for achieving protection in the newborns

BackgroundIn the US, influenza vaccination is recommended annually to everyone ≥6 months. Prior receipt of influenza vaccine can dampen antibody responses to subsequent vaccination. This may have implications for pregnant women and their newborns, groups at high risk for complications from influenza infection.ObjectiveThis study examined effects of prior vaccination on maternal and cord blood antibody levels in a cohort of pregnant women in the US.Study designInfluenza antibody titers were measured in 141 pregnant women via the hemagglutination inhibition (HAI) assay prior to receipt of quadrivalent influenza vaccine, 30 days post-vaccination, and at delivery (maternal and cord blood). Logistic regression analyses adjusting for age, BMI, parity, gestational age at vaccination, and year of vaccination compared HAI titers, seroprotection, and seroconversion in women with versus without vaccination in the prior year.ResultsCompared to those without vaccination in the previous year (n = 50), women with prior vaccination (n = 91) exhibited higher baseline antibody titers and/or seroprotection rates against all four strains after controlling for covariates. Prior vaccination also predicted lower antibody responses and seroconversion rates at one month post-vaccination. However, at delivery, there were no significant differences in antibody titers or seroprotection rates in women or newborns, and no meaningful differences in the efficiency of antibody transfer, as indicated by the ratio of cord blood to maternal antibody titers at the time of delivery.ConclusionIn this cohort of pregnant women, receipt of influenza vaccine the previous year predicted higher baseline antibody titers and decreased antibody responses at one month post-vaccination against all influenza strains. However, prior maternal vaccination did not significantly affect either maternal antibody levels at delivery or antibody levels transferred to the neonate. This study is registered with the NIH as a clinical trial (NCT02148874).     

Rubella specific cell-mediated and humoral immunity following vaccination in college students with low antibody titers

ObjectiveThis study measured cell-mediated immunity (CMI) and antibodies to clarify the basis of rubella reinfection after vaccination.MethodsIn a pool of 65 college students, 39 who exhibited hemagglutination–inhibition (HI) antibody titers against rubella of ≤1:16 were vaccinated with a rubella vaccine. The CMI was assessed with interferon-gamma release assay.ResultsThere was low correlation (r = 0.24) between the antibody titers and interferon-gamma levels at pre-vaccination status. Preexisting interferon-gamma levels were low in some subjects with low HI antibody titers of 1:8 and 1:16. Fifty-seven percent (4/7) of the subjects who were antibody-negative with past history of rubella vaccination at entry onto the study exhibited CMI. And 57% (4/7) of the subjects remained antibody-negative following a second vaccination, despite exhibiting CMI. HI antibody titers increased significantly after vaccination, whereas post-vaccination interferon-gamma levels did not exhibit significant increases. When subjects were divided (based on their past history of vaccination and antibody values) into natural infection and vaccination groups, HI antibody titers (mean ± SD) increased to 1:2^4.4 ± 1.4 from 1: 2^3.2 ± 0.4 (p = 0.065) in the natural infection group and to 1:2^4.4 ± 1.0 from 1:2^3.0 ± 0.8 (p < 0.00001) in the vaccination group following vaccination. The same classification revealed that interferon-gamma values did not increase significantly in either group following vaccination, but the interferon-gamma values at pre- and post-vaccination in the natural infection group were significantly higher than those at pre- and post-vaccination in the vaccination group (p < 0.05 and p < 0.05, respectively).ConclusionPre-vaccination interferon-gamma levels in each HI antibody titer group were similar. And there were some subjects with antibody-positive exhibited CMI-negative. These data may explain why rubella reinfection can occur in vaccinated seropositive individuals.     

Vitamin D levels and influenza vaccine immunogenicity among HIV-infected and HIV-uninfected adults

BackgroundVaccination is the most important preventive strategy against influenza, however post-vaccination antibody responses are often inadequate especially among HIV-infected persons. Vitamin D deficiency has been suggested to adversely influence immune responses and is highly prevalent among HIV-infected adults. Therefore, we evaluated the association between 25-hydroxyvitamin D [25(OH)D] levels and post-influenza vaccination responses.MethodsWe conducted a prospective cohort study evaluating the immunogenicity of monovalent influenza A (H1N1) vaccination among both HIV-infected and HIV-uninfected adults (18–50 years of age) during the 2009–2010 influenza season. Antibody titers were evaluated at baseline, day 28, and 6 months post-vaccination using hemagluttination inhibition assays. Serum 25(OH)D levels were measured at day 28. Univariate and multivariate regression analyses examined the association between 25(OH)D levels [categorized as <20 ng/ml (deficiency) vs. ⩾20 ng/ml] with the primary outcome of seroconversion. Secondary outcomes included seroprotection; a ⩾4-fold increase in titers; and geometric mean titers post-vaccination. Analyses were repeated using 25(OH)D levels as a continuous variable.ResultsA total of 128 adults [64 HIV-infected (median CD4 count 580 cells/mm³) and 64 HIV-uninfected] were included. Seroconversion at day 28 post-vaccination was achieved in fewer HIV-infected participants compared with HIV-uninfected participants (56% vs. 74%, p = 0.03). Vitamin D deficiency was more prevalent among HIV-infected persons vs. HIV-uninfected persons (25% vs. 17%), although not significantly different (p = 0.39). There were no associations found between lower 25(OH)D levels and poorer antibody responses at day 28 or 6 months for any of the study outcomes among either HIV-infected or HIV-uninfected adults.ConclusionVitamin D deficiency was common among both HIV-infected and HIV-uninfected adults, but lower levels did not predict antibody responses after H1N1 (2009) influenza vaccination. Low 25(OH)D levels do not explain poorer post-vaccination responses among HIV-infected persons.     

Factors associated with vaccination status among Korean submariners who are eligible for free non-mandatory influenza vaccination

IntroductionSubmarine crews live in a confined setting and are vulnerable to influenza. Thus, it would be useful to identify factors that are associated with influenza vaccination. In this study, we investigated the influenza vaccination rate and the influence of health beliefs on the vaccination rate among submariners who were eligible for a free but non-mandatory vaccination program.MethodsA total of 487 Korean submariners participated in this study after the closing of a free influenza vaccination program in 2015. Data regarding the participants’ general characteristics and health beliefs (based on the health belief model [HBM]) were collected using a self-administered questionnaire, and their vaccination status was determined using their medical records. Multiple logistic regression analysis were performed to evaluate the associations of the HBM components with influenza vaccination.ResultsThe overall vaccination rate was 78% (921/1183). The unvaccinated and vaccinated respondents exhibited similar characteristics, although the vaccinated group was significantly more likely to have high-risk family members (chronic disease, age of <2 years, or age of ⩾65 years; p = 0.025). Among the HBM components, perceived severity (odds ratio: 1.38, p = 0.019) and cue to action (odds ratio: 1.74, p = 0.002) were significantly associated with a higher likelihood of influenza vaccination.ConclusionVaccination policies that emphasize the severity of influenza and prompt individuals to undergo vaccination are needed to increase the vaccination rate among people who live in confined environments or institutions with non-mandatory vaccination programs.     

Trends in reasons for non-receipt of influenza vaccination during pregnancy in Georgia, 2004–2011

BackgroundConsiderable research has identified barriers to antenatal influenza vaccination, yet no research has explored temporal trends in reasons for non-receipt.PurposeTo examine trends in reasons for non-receipt of influenza vaccination during pregnancy.MethodsSerial cross-sectional analyses using 8 years of Georgia Pregnancy Risk Assessment Monitoring Survey (PRAMS) data were conducted. Weighted logistic regression was used to examine trends in the prevalence of citing reasons for non-receipt over time.ResultsBetween 2004 and 2011, 8300 women reported no influenza vaccination during or immediately before pregnancy. Proportions of women citing “doctor didn’t mention vaccination,” “in first trimester during influenza season,” and “not pregnant during influenza season” decreased significantly over time (Doctor didn’t mention: 48.0% vs. 27.1%, test for trend p < 0.001; in first trimester: 26.8% vs. 16.3%, test for trend p < 0.001; not influenza season: 24.2% vs. 12.7%, test for trend p = 0.001). Safety concerns increased over 2004 proportions in 2010 (concern about side effects for me: 40.2% vs. 28.5%, prevalence ratio (PR): 1.41, 95% confidence interval (CI): 1.16, 1.71; concern about harming my baby: 38.9% vs. 31.0%, PR = 1.26, 95% CI: 1.04, 1.53) and 2011 (concern about side effects for me: 39.0% vs. 28.5%, PR = 1.37, 95% CI: 1.13, 1.65; concern about harming my baby: 38.8% vs. 31.0%, PR = 1.25, 95% CI: 1.04, 1.50). Following the 2009/2010 H1N1 pandemic, more Hispanic women cited concern about vaccination harming their baby than other women; in 2011, their concern remained elevated relative to non-Hispanic white women (63% vs. 35%; adjusted PR = 1.79, 95% CI: 1.23, 2.61).ConclusionExamining trends in reasons for non-receipt of antenatal influenza vaccination can reflect successes related to vaccine promotion and areas for improvement. By highlighting differential impacts of the 2009/2010 H1N1 pandemic, we reveal opportunities for additional research on tailoring vaccine promotion efforts to specific types of women.     

The impacts of email reminder/recall on adolescent influenza vaccination

BackgroundWe sought to: (1) explore the feasibility of using email for seasonal influenza vaccination reminders to parents of adolescents and (2) assess influenza vaccination rates among adolescents whose parents were randomized to either receive or not receive email reminders.MethodsEmail addresses were obtained for parents of patients 10–18 years from 4 practices in Michigan. Addresses were randomized to either receive email reminders, or not. Reminder messages were sent during October 2012-March 2013 (Season 1) and October 2013-March 2014 (Season 2). Vaccination status was determined 60 days following the last email reminder for each season using the statewide Michigan Care Improvement Registry (MCIR); per protocol bivariate and multivariate logistic regression analyses were conducted to evaluate reminder notification.ResultsAfter email cleaning, testing, and matching with MCIR, approximately half of email addresses (2348 of 5312 in Season 1; 3457 of 6549 in Season 2) were randomized. Bivariate analyses found that influenza vaccination within 60 days after notification date was similar among those notified (34%) versus not notified (29%) in both Season 1 (p = 0.06) and Season 2 (39% vs. 37%, p = 0.20). However, multivariate models adjusted for season, site, and receipt of notification in two seasons found a higher likelihood of influenza vaccination among children that received notification (aOR = 1.28, 95% CI = 1.09, 1.51); in addition, differences in influenza vaccination were also observed between practice sites (range: p = 0.15 to p < 0.001).ConclusionsWe found that practice-based email influenza vaccine reminders to parents of adolescents are feasible, but not without complications. Our study demonstrates that email reminders from practices can yield increases in influenza vaccination rates among adolescents. Practices should consider email as an option for influenza reminders and establish business practices for collecting and maintaining patient email addresses.This study is registered at www.ClinicalTrials.gov id #NCT01732315.     

Efficacy and safety of high-dose influenza vaccine in elderly adults: A systematic review and meta-analysis

IntroductionOlder adults are prioritized for influenza vaccination but also have lowered antibody responses to the vaccine. Higher-doses of influenza antigen may increase immune response and thus be more effective. Our objectives were to compare the efficacy and safety of the high-dose influenza vaccine to the standard-dose influenza vaccine in the elderly (age > 65).MethodsData sources: Randomized trials (RCTs) from Medline (Ovid), EMBASE (Ovid), Cochrane Library (Wiley), ClinicalTrials.gov, reference lists of relevant articles, and gray literature.Study selection: Two reviewers independently identified RCTs comparing high-dose influenza vaccine (60 μg of hemagglutinin per strain) to standard-dose influenza vaccine (15 μg of hemagglutinin per strain) in adults over the age of 65 years.Data extraction: Two reviewers independently extracted trial-level data including population characteristics, interventions, outcomes, and funding sources. Risk of bias was assessed using the Cochrane Risk of Bias tool.ResultsWe included seven eligible trials; all were categorized as having a low (n = 3) or unclear (n = 4) risk of bias. Patients receiving the high-dose vaccine had significantly less risk of developing laboratory-confirmed influenza infections (Relative Risk 0.76, 95%CI 0.65 to 0.90; I² 0%, 2 trials, 41,141 patients). Post-vaccination geometric mean titres and seroprotection rates were also higher in high-dose vaccine recipients. There were no protocol-defined serious adverse events in the included trials in either group.ConclusionsIn elderly adults, the high-dose influenza vaccine was well-tolerated, more immunogenic, and more efficacious in preventing influenza infections than the standard-dose vaccine. Further pragmatic trials are needed to determine if the higher efficacy translates into higher vaccine effectiveness in adults over the age of 65.     

Immunogenicity and safety of concomitant MF59-adjuvanted influenza vaccine and 23-valent pneumococcal polysaccharide vaccine administration in older adults

BackgroundConcomitant administration of influenza and pneumococcal vaccines facilitates their uptake by older adults; however, data on immunogenicity and safety of concomitant administration of adjuvanted trivalent inactivated influenza vaccine (aIIV3) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) have not been reported.MethodsSubjects aged ≥65 years (N = 224) were randomized 1:1:1:1 to receive MF59-aIIV3 alone, MF59-aIIV3 + PPSV23 in contralateral arms, MF59-aIIV3 + PPSV23 in the same arm or PPSV23 alone (Clinical Trial Number – NCT02225327). Hemagglutination inhibition assay and multiplex opsonophagocytic killing assay were used to compare immunogenicity after single or concomitant vaccination.ResultsAll groups met immunogenicity criteria for the influenza vaccine in older adults with similar seroconversion rates and geometric mean fold-increases, irrespective of concomitant vaccinations and injection site. For each pneumococcal serotype, opsonic index (OI) increased markedly after the PPSV23 vaccination, irrespective of the concomitant influenza vaccine. All subjects showed an OI ≥ 8 for serotypes 6B, 18C and 19A post-vaccination, with a suggestion that the ipsilateral concomitant vaccination might be associated with higher OIs for some antigens. Local and systemic adverse events were more common in subjects receiving PPSV23 compared to those receiving aIIV3 alone.ConclusionsNo interference was observed with antibody responses to influenza or pneumococcal antigens when aIIV3 and PPSV23 were administered concomitantly.