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.     

Influenza vaccination coverage among patients and healthcare workers in a university hospital during the 2006–2007 influenza season

Despite years of public health effort to increase vaccine uptake among populations recommended for influenza vaccination, immunization rates remain low among patients and healthcare workers (HCWs). The objective of this study was to report on influenza vaccination coverage of patients and HCWs for the same time period in 4 wards of a university hospital. A prospective cross-sectional study was conducted among patients and HCWs between December 11, 2006 and April 15, 2007 and individual factors associated with being vaccinated against influenza were assessed. Results indicated that older patients were significantly more vaccinated than younger patients. Physicians and residents were more likely to be vaccinated that the rest of staff, with possible differences between wards. Immunization of HCWs is a major issue in infection control in hospitals and long-term care facilities. However, the impact of influenza vaccination among HCWs in reducing hospital-acquired influenza and patient morbidity needs to be explored further.     

Knowledge of influenza vaccination recommendation and early vaccination uptake during the 2015–16 season among adults aged ≥18 years – United States

BackgroundSince 2010, the Advisory Committee on Immunization Practices (ACIP) has recommended that all persons aged ≥6 months receive annual influenza vaccination.MethodsWe analyzed data from the 2015 National Internet Flu Survey (NIFS), to assess knowledge and awareness of the influenza vaccination recommendation and early influenza vaccination coverage during the 2015–16 season among adults. Predictive marginals from a multivariable logistic regression model were used to identify factors independently associated with adults’ knowledge and awareness of the vaccination recommendation and early vaccine uptake during the 2015–16 influenza season.ResultsAmong the 3301 respondents aged ≥18 years, 19.6% indicated knowing that influenza vaccination is recommended for all persons aged ≥6 months. Of respondents, 62.3% indicated awareness that there was a recommendation for influenza vaccination, but did not indicate correct knowledge of the recommended age group. Overall, 39.9% of adults aged ≥18 years reported having an influenza vaccination. Age 65 years and older, being female, having a college or higher education, not being in work force, having annual household income ≥$75,000, reporting having received an influenza vaccination early in the 2015–16 season, having children aged ≤17 years in the household, and having high-risk conditions were independently associated with a higher correct knowledge of the influenza vaccination recommendation.ConclusionsApproximately 1 in 5 had correct knowledge of the recommendation that all persons aged ≥6 months should receive an influenza vaccination annually, with some socio-economic groups being even less aware. Clinic based education in combination with strategies known to increase uptake of recommended vaccines, such as patient reminder/recall systems and other healthcare system-based interventions are needed to improve vaccination, which could also improve awareness.     

Do recommended high-risk adults benefit from a first influenza vaccination?

It is unknown whether a first influenza vaccination protects high-risk adults from severe morbidity and mortality during influenza epidemics. As part of the PRISMA nested case-control study, we aimed to evaluate the effectiveness of first-time and repeat influenza vaccinations in adult persons recommended for vaccination aged between 18 and 64 years during the 1999-2000 influenza A epidemic. After adjustments, 69% of hospitalizations for acute respiratory or cardiovascular disease or death were prevented in first-time vaccinees (95% percent confidence interval [95% CI]: 8-90%). The corresponding figure in persons who were vaccinated before was 85% (95% CI: 36-96%). Adult persons with high-risk medical conditions can substantially benefit from a first and repeat influenza vaccination prior to an epidemic.     

Sustained high influenza vaccination rates and decreased safety concerns among pregnant women during the 2010–2011 influenza season

Objective

Intense efforts to vaccinate pregnant women against 2009 H1N1 influenza resulted in much higher vaccine uptake than previously reported. We surveyed postpartum women to determine whether high vaccination rates were sustained during the 2010–11 influenza season.

Methods

We performed cross-sectional surveys of postpartum women delivering at our institution during February–April 2010 and February–March 2011. The surveys ascertained maternal characteristics, history of influenza vaccination, and reasons for lack of vaccination.

Results

During the 2010–11 season, 165 (55%) of 300 women surveyed reported receiving influenza vaccination, compared to 191 of 307 (62%) during 2009–10 (p = 0.08). Vaccination by an obstetrical provider was common, but decreased compared to 2009–10 (60% vs. 71%, p = 0.04). While most women (76%) in 2010–11 reported that their provider recommended influenza vaccination, significantly more reported lack of discussion about vaccination (24% vs. 11%, p < 0.01) compared to 2009–10. Vaccine safety concerns were cited by most (66%) women declining vaccination during 2009–10 but only 27% of women who declined in 2010–11.

Conclusion

The vaccination rate among pregnant women at our institution was relatively sustained, although fewer providers appear to be discussing influenza vaccination in pregnancy. Concern about vaccine safety, the primary barrier during 2009–10, was much less prominent.     

Disparities in influenza vaccination for U.S. adults with disabilities living in community settings by race/ethnicity, 2016–2021

BackgroundThere is a paucity of data examining disparities in influenza vaccination at the intersection of disability and race.ObjectiveTo compare the prevalence of influenza vaccination between U.S. adults (≥18 years) with and without disabilities living in community settings, and to examine changes in influenza vaccination over time by disability status and race/ethnicity groups.MethodsWe analyzed cross-sectional data from the Behavioral Risk Factor Surveillance System (2016–2021). We calculated the annual age-standardized prevalence of influenza vaccination (last 12 months) in individuals with and without disabilities (2016–2021), and examined percentage changes (2016–2021) by groups of disability status and race/ethnicity.ResultsFrom 2016 to 2021, the annual age-standardized prevalence of influenza vaccination was consistently lower in adults with disabilities as compared to those without disabilities. In 2016, 36.8% (95%CI: 36.1%–37.4%) of adults with disabilities had an influenza vaccine versus 37.3% (95%CI: 36.9%–37.6%) of those without disabilities. In 2021, 40.7% (95%CI: 40.0%–41.4%) and 44.1% (95%CI: 43.7%–44.5%) of adults with and without disabilities had an influenza vaccine.The percentage change in influenza vaccination from 2016 to 2021 was lower among people with disabilities (10.7%, 95%CI: 10.4%–11.0%; vs. no disability: 18.4%, 95%CI: 18.1%–18.7%). Among adults with disabilities, Asian adults reported the largest percentage increase in influenza vaccination (18.0%, 95% CI: 14.2%, 21.8%; p: 0.07), and Black, Non-Hispanics adults reported the lowest (2.1%, 95% CI: 1.9%, 2.2%; p: 0.59).ConclusionsStrategies to increase influenza vaccination in the U.S. should address barriers faced by people with disabilities, particularly the intersectional barriers faced by people with disabilities from racial and ethnic minority groups.     

Influenza vaccine effectiveness among patients with high-risk medical conditions in the United States, 2012–2016

BackgroundAnnual influenza vaccination has been recommended for persons with high-risk conditions since the 1960s. However, few estimates of influenza vaccine effectiveness (VE) for persons with high-risk conditions are available.MethodsData from the U.S. Influenza Vaccine Effectiveness Network from 2012 to 2016 were analyzed to compare VE of standard-dose inactivated vaccines against medically-attended influenza among patients aged ≥6 months with and without high-risk medical conditions. Patients with acute respiratory illness were tested for influenza by RT-PCR. Presence of high-risk conditions and vaccination status were obtained from medical records. VE by influenza virus type/subtype and age group was calculated for patients with and without high-risk conditions using the test-negative design. Interaction terms were used to test for differences in VE by high-risk conditions.ResultsOverall, 9643 (38%) of 25,369 patients enrolled during four influenza seasons had high-risk conditions; 2213 (23%) tested positive for influenza infection. For all ages, VE against any influenza was lower among patients with high-risk conditions (41%, 95% CI: 35–47%) than those without (48%, 95% CI: 43–52%; P-for-interaction = 0.02). For children aged <18 years, VE against any influenza was 51% (95% CI: 39–61%) and 52% (95% CI: 39–61%) among those with and without high-risk conditions, respectively (P-for-interaction = 0.54). For adults aged ≥18 years, VE against any influenza was 38% (95% CI: 30–45%) and 44% (95% CI: 38–50%) among those with and without high-risk conditions, respectively (P-for-interaction = 0.21). For both children aged <18 and adults aged ≥18 years, VEs against illness related to influenza A(H3N2), A(H1N1)pdm09, and influenza B virus infection were similar among those with and without high-risk conditions.ConclusionsInfluenza vaccination provided protection against medically-attended influenza among patients with high-risk conditions, at levels approaching those observed among patients without high-risk conditions. Results from our analysis support recommendations of annual vaccination for patients with high-risk conditions.     

Reasons given for not receiving an influenza vaccination, 2011–12 influenza season,United States

BackgroundInfluenza vaccination coverage in the United States remains below national targets and racial/ethnic differences persist.ObjectivesTo gain insights into potential strategies for improving influenza vaccination by examining reasons given for not receiving an influenza vaccination during the 2011–12 influenza season.MethodsData from the National Flu Survey were analyzed for the 2011–12 influenza season.Tests of association between reasons for non-vaccination and demographic variables were conducted using Wald chi-square tests. Multivariable logistic regression analyses were used to determine variables independently associated with each reason for non-vaccination.ResultsFor adults and children, there were no racial/ethnic differences in the overall most frequent reason for non-vaccination: “unlikely to get very sick from the flu”. Regarding adults, there were racial/ethnic differences in seven of the twelve reasons for non-vaccination in bivariate analyses, but only three remained significant in the multivariable models. Most notable of these was that blacks (40.9%) were more likely than Hispanics (27.0%), whites (25.2%), and adults of other/multiple races (21.2%) to report concerns about getting the flu from the vaccination and blacks (39.8%) were more likely than whites (28.4%) and adults of other/multiple races (29.3%) to report concerns about side effects from the vaccine. Regarding children, there were racial/ethnic differences for three of the reasons for non-vaccination, and these remained significant in the multivariable models. The most noteworthy of these was that more black (44.4%) than white (24.0%) and other/multiple race (19.0%) parents had concerns about their child getting the flu from the vaccination. Other demographic variables (age, gender income, MSA for adults and age and income for children) were also associated with reasons for non-vaccination based on the multivariable models.ConclusionsThere are racial/ethnic group differences in reasons for not receiving an influenza vaccination; recognition of these differences should guide the choice of interventions to increase vaccination rates.     

Comparison of alpha-spending plans for near real-time monitoring for Guillain-Barré Syndrome after influenza vaccination during the 2010/11 influenza season

BackgroundNear real-time surveillance of the influenza vaccine, which is administered to a large proportion of the US population every year, is essential to ensure safety of the vaccine. For efficient near real-time surveillance, it is key to select appropriate parameters such as monitoring start date, number of interim tests and a scheme for spending a pre-defined total alpha across the entire influenza season. Guillain-Barré Syndrome, shown to be associated with the 1976 influenza vaccine, is used to evaluate how choices of these parameters can affect whether or not a signal is detected and the time to signal. FDA has been monitoring for the risk of GBS after influenza vaccination for every influenza season since 2008.MethodsUsing Medicare administrative data and the Updating Sequential Probability Ratio Test methodology to account for claims delay, we evaluated a number of different alpha-spending plans by varying several parameters.ResultsFor relative risks of 5 or greater, almost all alpha-spending plans have 100% power; however, for relative risks of 1.5 or lower, the constant and O’Brien-Fleming plans have increasingly more power. For RRs of 1.5 and greater, the Pocock plan signals earliest but would not signal at a RR of 1.25, as observed in prior influenza seasons. There were no remarkable differences across the different plans in regards to monitoring start dates defined by the number of vaccinations; reducing the number of interim tests improves performance only marginally.ConclusionsA constant alpha-spending plan appears to be robust, in terms of power and time to detect a signal, across a range of these parameters, including alternate monitoring start dates based on either cumulative vaccinations or GBS claims observed, frequency of monitoring, hypothetical relative risks, and vaccine uptake patterns.     

Recommendations and offers for adult influenza vaccination, 2011–2012 season,United States

BackgroundProvider recommendations and offers for influenza vaccination improve adult influenza vaccination coverage. Analysis was performed to describe receipt of influenza vaccination recommendations and offers among adults who visited a healthcare provider (HCP) during the 2011–2012 influenza season and describe differences between those receiving and not receiving recommendations and offers for influenza vaccination. Associations between influenza vaccination and receipt of recommendations and offers were examined.MethodsRespondents to a random digit dial telephone survey who had visited a HCP since July 1, 2011 were asked if they had received a recommendation for influenza vaccination. Those receiving a recommendation were asked if they received an offer for vaccination. Participants were characterized by demographic and access to health care variables. Logistic regression was used to examine the relationships between participant characteristics and recommendation alone, between participant characteristics and recommendation and offer, and between influenza vaccination and recommendation and offer.ResultsOf those who reported visiting a HCP, 43.8% reported receiving a recommendation for influenza vaccination. Of those who reported receiving a recommendation, 76.6% reported receiving an offer for influenza vaccination. Persons with high-risk conditions and persons over 65 years were more likely to receive recommendations for influenza vaccination when compared to those without high-risk conditions and 18–49 year olds, respectively. Those reporting receipt of a recommendation and offer for influenza vaccination were 1.76 times more likely and those reporting receipt of a recommendation but no offer were 1.72 times more likely to report being vaccinated for influenza controlling for all patient characteristics.ConclusionsLess than half of respondents reported receipt of recommendations and offers of influenza vaccination during the 2011–2012 influenza season and disparities exist between groups. All healthcare providers seeing adults should recommend or offer influenza vaccination for all patients at every visit during the influenza season.     

Influenza vaccine effectiveness against medically-attended influenza illness during the 2012–2013 season in Beijing,China

Background

Influenza vaccine coverage remains low in China, and there is limited information on the preventive value of local vaccination programs.

Methods

As part of influenza virological surveillance in Beijing, China during the 2012–2013 influenza season, we assessed the vaccine effectiveness (VE) of one or more doses of trivalent inactivated influenza vaccine (IIV3) in preventing medically-attended influenza-like-illness (ILI) associated with laboratory-confirmed influenza virus infection using a test-negative case–control design. Influenza vaccination was determined based on self-report by adult patients or the parents of child patients.

Results

Of 1998 patients with ILI, 695 (35%) tested positive for influenza viruses, including 292 (42%) A(H3N2), 398 (57%) A(H1N1)pdm09, and 5 (1%) not (sub)typed influenza viruses. The rate of influenza vaccination among all patients was 4% (71/1998). Among influenza positive patients, 2% (57/1303) were vaccinated compared to 4% (14/695) among influenza negative patients, resulting in VE for one or more doses of vaccine (adjusted for age, sex, week, and days since illness onset) against all circulating influenza viruses of 52% (95% CI = 12–74%). A significant adjusted VE for one or more doses of vaccine for all ages against A(H1N1)pdm09 of 59% (95% CI, 8–82%) was observed; however, the VE against A(H3N2) was 43% (95% CI, −30% to 75%). The point estimate of VE was 59% (95% CI, 19–79%) for those aged <60 years, but a negative VE point estimate without statistical significance was observed among those aged ≥60 years.

Conclusions

IIV3 conferred moderate protection against medically-attended influenza in Beijing, China during the 2012–2013 season, especially against the A(H1N1)pdm09 strain and among those aged <60 years old.     

National and state-specific estimates of place of influenza vaccination among adult populations – United States, 2011–12 influenza season

Background

Annual influenza vaccination has been recommended for all persons ≥6 months since the 2010–11 season. New partnerships between public health agencies and medical and nonmedical vaccination providers have increased the number of vaccination providers and locations where vaccination services are delivered.

Methods

Data from the 2011–12 Behavioral Risk Factor Surveillance System (BRFSS) were analyzed. Point estimates of place of vaccination and 95% confidence intervals were calculated. Multivariable logistic regression and predictive marginal modeling were conducted to identify factors associated with vaccination settings.

Results

Among adults vaccinated during the 2011–12 influenza season, a doctor's office was the most common place (38.4%) for receipt of influenza vaccination, with stores (e.g., supermarkets or drug stores) (20.1%) the next common, and workplaces (17.6%) the third common. Overall, reported vaccination in nonmedical settings by state ranged from 32.2% in California to 60.4% in Nevada, with a median of 45.8%. Characteristics significantly associated with an increased likelihood of receipt of vaccination in nonmedical settings were higher education, not having certain identified high-risk conditions, not having had a routine checkup in the previous 12 months, and not having a primary doctor for health care. Being a member of a racial/ethnic minority group, unemployed or not in the work force were significantly associated with a decreased likelihood of receipt of vaccination in nonmedical settings.

Conclusion

Doctor's offices were the most common medical setting for adult influenza vaccination; workplaces and stores were important nonmedical settings. Increasing access to vaccination services in medical and nonmedical settings should be considered as important strategies for improving vaccination coverage. These results also can help guide development of strategies for achieving Healthy People 2020 objectives for influenza vaccination of adult populations.     

Surveillance for Guillain-Barré syndrome after 2015–2016 and 2016–2017 influenza vaccination of Medicare beneficiaries

BackgroundGuillain-Barré syndrome (GBS) is a serious acute demyelinating disease, an increased risk of which was found after the 1976 swine flu vaccinations. The U.S. Food and Drug Administration, in collaboration with the Centers for Medicare & Medicaid Services, has been conducting active surveillance for GBS after influenza vaccinations of Medicare Fee-For-Service beneficiaries since 2009.MethodsWe conducted active surveillance for GBS claims in the 2015–2016 and 2016–2017 influenza seasons using the Updating Sequential Probability Ratio Test (USPRT) to monitor for signals of GBS risk. We performed self-controlled risk interval (SCRI) analyses at the end of both seasons, including chart confirmation in the 2015–2016 season, to estimate the odds ratio of GBS risk. We used 1–42 and 8–21 days post-vaccination as primary and secondary risk windows, respectively, and 43–84 days post-vaccination as the control window.ResultsOver 13 million beneficiaries were vaccinated in each season. USPRT found a low magnitude signal for GBS in both seasons. SCRI analyses did not find excess GBS risk following any influenza vaccine for days 1–42 post-vaccination in either season. In the 2015–2016 season, for the 8–21 day window, our chart-confirmation showed an attributable GBS risk of 0.87 (95% CI: 0.16, 1.49) and 1.68 (95% CI: 0.69, 2.41) cases per million vaccinees after all seasonal and high dose (HD) vaccines, respectively, an elevated GBS risk for beneficiaries aged ≥75 years following all seasonal vaccines (OR: 2.25; 95% CI: 1.15, 4.39) and HD vaccine (OR: 3.67, 95% CI: 1.52, 8.85), and an elevated GBS risk for males who received seasonal vaccines (OR: 2.18; 95% CI: 1.15, 4.15) and HD vaccine (OR: 3.33; 95% CI: 1.35, 8.20). The finding of elevated GBS risk with advancing age and in males is consistent with literature; however, a distinction between HD and SD was a new finding. In the 2016–17 season, for the 8–21 day window, attributed cases showed an attributable GBS risk of 0.87 (95% CI: 0.03, 1.61) and 1.11 (95% CI: 0.00, 2.01) cases per million vaccinees after all seasonal and HD vaccines, respectively. We found no excess GBS risk for standard dose vaccines in the 8–21 day window in either season.ConclusionsOur primary analysis finding of no excess GBS risk during both seasons was reassuring. The slightly elevated GBS risk, although in the expected range, in the 8–21 day window after all seasonal and high dose vaccines, but not after standard dose vaccines is hypothesis-generating because the difference may be due to vaccine factors such as antigen amount or strains in various seasons or due to host factors.     

Influenza vaccine effectiveness against laboratory confirmed influenza in Greece during the 2013–2014 season: A test-negative study

BackgroundIn 2013–2014 Greece experienced a resurgence of severe influenza cases, coincidental with a shift to H1N1pdm09 predominance. We sought to estimate Vaccine Effectiveness (VE) for this season using available surveillance data from hospitals (including both inpatients and outpatients).MethodsSwab samples were sent by hospital physicians to one of three laboratories, covering the entire country, to be tested for influenza using RT-PCR. The test-negative design was employed, with patients testing positive serving as cases and those testing negative serving as controls. VE was estimated using logistic regression, adjusted for age group, sex, region and calendar time, with further adjustment for unknown vaccination status using inverse response propensity weights. Additional age group stratified estimates and subgroup estimates of VE against H1N1pdm09 and H3N2 were calculated.ResultsOut of 1310 patients with known vaccination status, 124 (9.5%) were vaccinated, and 543 patients (41.5%) tested positive for influenza. Adjusted VE was 34.5% (95% CI: 4.1–55.3%) against any influenza, and 56.7% (95% CI: 22.8–75.7%) against H1N1pdm09. VE estimates appeared to be higher for people aged 60 and older, while in those under 60 there was limited evidence of effectiveness. Isolated circulating strains were genetically close to the vaccine strain, with limited evidence of antigenic drift.ConclusionsThese results suggest a moderate protective effect of the 2013–2014 influenza vaccine, mainly against H1N1pdm09 and in people aged 60 and over. Vaccine coverage was very low in Greece, even among groups targeted for vaccination, and substantial efforts should be made to improve it. VE can and should be routinely monitored, and the results taken into account when deciding on influenza vaccine composition for next season.     

Influenza vaccination coverage among adult solid organ transplant recipients at three health maintenance organizations, 1995–2005

Annual immunization against influenza is recommended for solid organ transplant (SOT) recipients. We used Vaccine Safety Datalink data from 1995 to 2005 to assess influenza vaccination during the first full vaccination season (September–February) following transplant among 1800 kidney, liver, and heart transplant recipients at three health maintenance organizations. Overall, 52% of recipients were vaccinated. Older age at transplant (age 50–64 years, OR 1.81, 95% CI 1.43–2.30; age ≥65 years, OR 1.94, 95% CI 1.39–2.69), receiving vaccination in the full season pre-transplant (OR 4.54, 95% CI 3.67–5.60), and year of transplantation were significant predictors of post-transplant vaccination. Although vaccine coverage increased during study years, SOT recipients are under-immunized against influenza. Efforts to understand barriers to vaccination and increase education of physicians managing patients while awaiting and after receipt of transplant are needed.     

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.     

Seasonal influenza vaccination trends from 2007–2011 in privately insured children and adults in the United States

Background

To ensure adequate protection from seasonal influenza in the US, the Advisory Committee on Immunization Practices recommends vaccination of all persons aged 6 months or older, with rare exceptions. It also advises starting vaccination as soon as available and continuing throughout the influenza season. This study examined US seasonal vaccination trends during five consecutive influenza seasons in privately-insured children and adults.

Methods

This retrospective, observational cohort study examined trends in influenza vaccination during the 2007–2008 through 2011–2012 influenza seasons using administrative claims data from a large national insurer.

Results

The size of analysis population ranged from 1144,098 to 1245,487 (children, ≥6 months-17 years of age) and from 3931,622 to 4158,223 (adults, 18–64 years of age). Vaccination frequency increased through 2010–2011, was most frequent in young children, and decreased with age. Vaccination rates were highest in the Northeast and lowest in the West and were higher in individuals with frequent outpatient office visits than in those with no or rare visits, with larger differences seen in children. Between 2007 and 2011, the use of preservative-free inactivated vaccine increased, the use of multidose vaccines containing preservatives decreased, and the use of live attenuated influenza vaccines increased among children 2–17 years of age. From 2007–2008 through 2009–2010, the timing of vaccination each year began earlier than the previous one; it remained stable from 2009–2010 through 2011–2012.

Conclusion

Annual influenza vaccination claims for privately-insured children and adults increased and shifted earlier from 2007 through 2009–2011. During the 2011–2012 influenza season, 25.4% of children aged 6 months-17 years and 12.3% of adults aged 18–64 years were vaccinated. Increasing influenza vaccination should remain a priority, and alternative venues for seasonal influenza vaccination should be considered in order to meet the Healthy People 2020 goal of 80% to 90% coverage among children.     

Influenza vaccine effectiveness against hospitalization during the 2018/2019 season among older persons aged ≥ 75 years in Japan: The LIFE-VENUS Study

BackgroundOlder persons are recommended to receive annual influenza vaccinations due to their increased susceptibility to influenza infections and related complications. Routine assessments of influenza vaccine effectiveness (IVE) in older persons may help to improve vaccine development and vaccination strategies, but there is a lack of consistent epidemiological data from Japan. This study aimed to evaluate IVE against hospitalization during the 2018/2019 season among older persons aged ≥ 75 years in Japan.MethodsThis cohort study was conducted using insurance claims data and vaccination records provided by the Longevity Improvement & Fair Evidence - Vaccine Effectiveness, Networking, and Universal Safety (LIFE-VENUS) Study. The study cohort comprised older persons aged ≥ 75 years residing in an urban municipality in Japan. Vaccinated participants were identified through vaccination records from October 2018 to January 2019, and were matched with unvaccinated participants using a 1:1 ratio. The IVE against hospitalization was calculated as (1?hazard ratio) × 100% while adjusting for covariates such as age, sex, comorbidities, previous vaccinations, and care needs levels.ResultsWe analyzed 30,881 vaccinated participants matched with 30,881 unvaccinated participants. Among these, 587 (1.9%) vaccinated participants and 644 (2.1%) unvaccinated participants were hospitalized during the 2018/2019 season. The adjusted IVE against hospitalization was estimated to be 28.9% (16.6–39.4%).ConclusionsThe influenza vaccine for the 2018/2019 season showed moderate effectiveness among older persons in Japan. The LIFE-VENUS Study represents a potential platform for the continued monitoring of IVE among the older Japanese population.     

Impact of live attenuated influenza vaccination programme for healthy children in Northern Ireland: A comparison of seven influenza seasons, 2010/11–2016/17

Seasonal influenza vaccination for healthy children was introduced in Northern Ireland in the 2013/14 flu season, with an initial pilot year involving two specific cohorts, followed by rollout to all children aged 4–11 years in subsequent seasons. This study aimed to examine the impact of that programme on the burden of flu in primary care over the study period 2010/11–2016/17.Two routine indicators were used to measure impact – GP in-hour consultations and out-of-hour calls for influenza and influenza-like-illness (ILI). Analysis was conducted overall and stratified by age; rates in children under 14 years of age to measure direct impact and rates in individuals 14 years and over to measure indirect impact. Seven influenza seasons were included, three pre-programme seasons (2010/11–2012/13: phase 0), one pilot season (2013/14: phase 1), and three post-programme seasons (2014/15–2016/17: phase 2).High uptake of vaccination was observed from the programme introduction, with consistent uptake of over 50% in pre-school age groups and over 75% in primary school age groups. Statistically significant reductions were found in GP in-hours consultations and in out-of-hour calls in phase 2 compared to phase 0, both overall (GP in-hours RR 0.61, 95% CI 0.38–0.98, p = .040; out-of-hours RR 0.51, 95% CI 0.27–0.97, p = .041) and in the under 14 years group (GP in-hours RR 0.38, 95% CI 0.19–0.75, p = .006; out-of-hours RR 0.39, 95% CI 0.19–0.83, p = .014).Our results suggest that there have been reductions in the burden of flu in primary care settings overall and in children aged under 14 years in the seasons since the introduction of healthy children influenza vaccination. Further seasons should be added to subsequent analyses to strengthen this evidence.