Influenza vaccination coverages among children, adults, health care workers and immigrants in Spain: Related factors and trends, 2003–2006

Vaccination against influenza: Coverage and adherence in children under 15 years with high-risk medical conditions in the Community of Madrid

INTRODUCTION

Vaccination against influenza is indicated in children at risk of complications or severe disease. The objective of this study was to describe the percentage of children aged less than 15 years with risk conditions vaccinated against influenza in the Community of Madrid, and to analyze the factors associated with adherence to vaccination throughout 3 vaccination campaigns.

MATERIALS AND METHODS

Population-based cross-sectional observational study of children aged 6 months to 14 years with conditions that indicated influenza vaccination at the beginning of the 2018-2019 campaign. Electronic population registers were used. We described the percentage of children vaccinated in 3 consecutive campaigns, and assessed the association of adherence to vaccination with demographic and socioeconomic variables and risk conditions using bivariate and multivariate analysis.

RESULTS

The vaccination coverage was 15.6% in the 2018-2019 campaign. The adherence to vaccination was 65.9%. The variables associated with greater adherence were age greater than 2 years, especially in the 6-10 years group (aOR = 1.63; 95% CI, 1.43-1.85) and presenting more than one risk condition, especially 3 or more diseases (aOR = 1.80; 95% CI, 1.00-3.26). Diabetes mellitus was the disease associated most strongly with adherence (aOR = 2.15; 95% CI, 1.74-2.65). Adherence was lower in the immigrant population (aOR = 0.43; 95% CI, 0.36-0.51). We found no association between vaccination adherence and sex or socioeconomic status.

CONCLUSIONS

Vaccination coverage and adherence were suboptimal. Adherence to vaccination against influenza is associated with demographic and clinical conditions. Strategies need to be established to increase vaccination in children, with greater involvement of professionals and education of parents.

Defining the determinants of vaccine uptake and undervaccination in migrant populations in Europe to improve routine and COVID-19 vaccine uptake: a systematic review

Understanding why some migrants in Europe are at risk of underimmunisation and show lower vaccination uptake for routine and COVID-19 vaccines is critical if we are to address vaccination inequities and meet the goals of WHO's new Immunisation Agenda 2030. We did a systematic review (PROSPERO: CRD42020219214) exploring barriers and facilitators of vaccine uptake (categorised using the 5As taxonomy: access, awareness, affordability, acceptance, activation) and sociodemographic determinants of undervaccination among migrants in the EU and European Economic Area, the UK, and Switzerland. We searched MEDLINE, CINAHL, and PsycINFO from 2000 to 2021 for primary research, with no restrictions on language. 5259 data sources were screened, with 67 studies included from 16 countries, representing 366 529 migrants. We identified multiple access barriers-including language, literacy, and communication barriers, practical and legal barriers to accessing and delivering vaccination services, and service barriers such as lack of specific guidelines and knowledge of health-care professionals-for key vaccines including measles-mumps-rubella, diphtheria-pertussis-tetanus, human papillomavirus, influenza, polio, and COVID-19 vaccines. Acceptance barriers were mostly reported in eastern European and Muslim migrants for human papillomavirus, measles, and influenza vaccines. We identified 23 significant determinants of undervaccination in migrants (p<0·05), including African origin, recent migration, and being a refugee or asylum seeker. We did not identify a strong overall association with gender or age. Tailored vaccination messaging, community outreach, and behavioural nudges facilitated uptake. Migrants' barriers to accessing health care are already well documented, and this Review confirms their role in limiting vaccine uptake. These findings hold immediate relevance to strengthening vaccination programmes in high-income countries, including for COVID-19, and suggest that tailored, culturally sensitive, and evidence-informed strategies, unambiguous public health messaging, and health system strengthening are needed to address access and acceptance barriers to vaccination in migrants and create opportunities and pathways for offering catch-up vaccinations to migrants.

Importance of Awareness and Treatment for Diabetes in Influenza Vaccination Coverage of Diabetic Patients under 65 Years: A Population-Based Study

BACKGROUND

Influenza is a global public health problem causing considerable morbidity and mortality. Although vaccination is the most effective way to prevent infection, vaccination coverage is insufficient in people with chronic disease under 65 years, especially diabetes. The purpose of this study was to evaluate influenza vaccination coverage and identify factors associated with influenza vaccination in Korean diabetic adults under 65 years.

METHODS

Data were obtained from 24,821 subjects in the Korea National Health and Nutrition Examination Survey (2014 to 2017). Socioeconomic, health-related, and diabetic factors were investigated for their relations with influenza vaccination in diabetic patients under 65 years using univariate and multivariate analyses.

RESULTS

Among 24,821 subjects, 1,185 were diabetic patients under 65 years and their influenza vaccination rate was 36.5%. Socioeconomic (older age, female gender, non-smoker, light alcohol drinker, lower educational level, and employed status), health-related factors (lower fasting glucose and glycosylated hemoglobin level, good self-perceived health status, more comorbidities, recent health screening, more outpatient visits, and diet therapy), and diabetic factors (more awareness and getting treated) were associated with influenza vaccination. In multivariate analysis, more awareness and getting treated for diabetes were associated with influenza vaccination in diabetic patients under 65 years (odds ratio, 1.496 and 1.413; 95% confidence interval, 1.022 to 2.188 and 1.018 to 2.054, respectively).

CONCLUSION

Influenza vaccination rate was low in diabetic patients under 65 years, especially in those with unawareness and not getting treated for diabetes. Active screening and treatment for diabetes may be helpful to improve the influenza vaccination rate in these patients.

Healthcare Services Utilization Among Migrants in Portugal: Results From the National Health Survey 2014

Migrants' health is attracting substantial global interest. We aimed to identify barriers and differences in healthcare services utilization between migrants and natives in a nationally representative sample using data from the National Health Survey 2014. A total of 18,165 participants providing information on country of birth and nationality were included, and comparison of healthcare services utilization was made by using participants born in Portugal and with Portuguese nationality as the reference group. Migrants reported a lower frequency of medical visits, a higher consumption of medication without a prescription and less use of preventive care services. The main reasons for not attending medical consultations among migrants were the absence of need and financial difficulties. This study illustrates inequalities in healthcare use among migrants in Portugal, and provides useful information for enlightening policymakers and healthcare providers to develop health policies that can address migrants' needs.

Influenza in Children With Special Risk Medical Conditions: A Systematic Review and Meta-analysis

BACKGROUND

Children with special risk medical conditions (SRMC) are over-represented in influenza hospitalizations. A systematic review was undertaken to determine whether children with SRMCs experience greater complications or severity following influenza infection.

METHODS

Bibliographies of pertinent articles were searched in MEDLINE and EMBASE (1990 to March 2018) and contact made with the investigators of unpublished studies containing relevant data. Studies of children (aged ≤18 years) with a SRMC hospitalized with influenza were included. Outcomes were pneumonia, intensive care unit (ICU) admission, mechanical ventilation, neurologic outcomes (seizures, encephalopathy), death and length of stay in hospital or ICU.

RESULTS

Twenty-two studies met inclusion criteria. Compared with healthy peers, children with SRMC had higher odds of ICU admission [pooled odds ratio (OR) 1.66 (95% confidence interval (CI): 1.25-2.21)], for mechanical ventilation [pooled OR 1.53 (95% CI: 0.93-2.52)] and death [pooled OR 1.34 (95% CI: 0.74-2.41)]. Additionally, children with SRMC were more likely to develop bacterial pneumonia (crude OR 1.7; 95% CI: 1.1-2.6) or experience prolonged hospital length of stay [adjusted rate ratio 1.75 (95% CI: 1.44-2.11)]. The level of GRADE evidence was low for all outcomes considered in this review.

CONCLUSIONS

While there was evidence that ICU management and bacterial pneumonia increases in children with SRMC, evidence showing an increase in the probability of death or need for mechanical ventilation was inconsistent. Further research using large datasets should evaluate the impact of complications and associated morbidity from influenza in SRMC children.

Zoster vaccination inequalities: A population based cohort study using linked data from the UK Clinical Practice Research Datalink

OBJECTIVE

To quantify inequalities in zoster vaccine uptake by determining its association with socio-demographic factors: age, gender, ethnicity, immigration status, deprivation (at Lower-layer Super Output Area-level), care home residence and living arrangements.

METHOD

This population-based cohort study utilised anonymised primary care electronic health records from England (Clinical Practice Research Datalink) linked to deprivation and hospitalisation data. Data from 35,333 individuals from 277 general practices in England and eligible for zoster vaccination during the two-year period (2013-2015) after vaccine introduction were analysed. Logistic regression was used to obtain adjusted odds ratios (aOR) for the association of socio-demographic factors with zoster vaccine uptake for adults aged 70 years (main target group) and adults aged 79 years (catch-up group).

RESULTS

Amongst those eligible for vaccination, 52.4% (n = 18,499) received the vaccine. Socio-demographic factors independently associated with lower zoster vaccine uptake in multivariable analyses were: being older (catch-up group: aged 79 years) aOR = 0.89 (95% confidence interval (CI):0.85-0.93), care home residence (aOR = 0.64 (95%CI: 0.57-0.73)) and living alone (aOR = 0.85 (95%CI: 0.81-0.90)). Uptake decreased with increasing levels of deprivation (p-value for trend<0.0001; aOR most deprived versus least deprived areas = 0.69 (95%CI: 0.64-0.75)). Uptake was also lower amongst those of non-White ethnicities (for example, Black versus White ethnicity: aOR = 0.61 (95%CI: 0.49-0.75)) but was not lower among immigrants after adjusting for ethnicity. Lower uptake was also seen amongst females compared to men in the catch-up group.

CONCLUSIONS

Inequalities in zoster vaccine uptake exist in England; with lower uptake among those of non-White ethnicities, and among those living alone, in a care home and in more deprived areas. Tailored interventions to increase uptake in these social groups should assist in realising the aim of mitigating vaccination inequalities. As care home residents are also at higher risk of zoster, improving the uptake of zoster vaccination in this group will also mitigate inequalities in zoster burden.

Determinants of non-vaccination against seasonal influenza in Canadian adults: findings from the 2015-2016 Influenza Immunization Coverage Survey

OBJECTIVES

The study objectives were to (1) identify determinants of non-vaccination against seasonal influenza in Canadian adults and (2) examine self-reported reasons for non-vaccination.

METHODS

The data source was the 2015-2016 Influenza Immunization Coverage Survey, a national telephone survey of Canadian adults. Participants (n = 1950) were divided into three groups: adults aged 18-64 years with (n = 408) and without (n = 1028) chronic medical conditions (CMC) and adults ≥ 65 years (n = 514). Logistic regression was used to measure associations between sociodemographic factors and non-vaccination for the 2015-2016 influenza season. Weighted proportions were calculated to determine the main self-reported reasons for not receiving the influenza vaccine.

RESULTS

Younger age was found to be associated with non-vaccination across all groups. In adults ≥ 65 years, elementary- or secondary- vs. university-level education (aOR 1.87, 95% CI 1.14-3.06) was also significantly associated with non-vaccination. Significant variation in vaccine uptake was found for several sociodemographic factors in adults aged 18-64 without CMC. Low perceived susceptibility or severity of influenza and lack of belief in the vaccine's effectiveness were the most commonly reported reasons for not receiving the vaccine.

CONCLUSION

In general, our results were consistent with findings from other Canadian and American studies on seasonal influenza vaccine uptake. Belief that the influenza vaccine is not needed was common, even among those at increased risk of influenza-related complications. Additional research is needed to better understand how sociodemographic factors such as income and education may influence uptake and to raise awareness of potential complications from influenza infection in high-risk adults.

Factors associated with acceptance of pandemic flu vaccine by healthcare professionals in Spain, 2009-2010

The A(H1N1)pdm09 influenza virus reached pandemic level in Spain in 2009, prompting a national vaccination campaign. To avoid transmission to patients, healthcare professionals' vaccination against pandemic influenza is crucial. The main objective of this study was to analyze factors associated with the failure by healthcare professionals to accept the pandemic vaccination in 2009. A cross-sectional survey was conducted of healthcare professionals in seven of Spain's autonomous regions. A questionnaire was used to collect information about personal and professional details, the respondents' flu vaccination status in the 2008-2009 and 2009-2010 seasons (seasonal and pandemic vaccines), and their knowledge and attitudes. A total of 1,661 professionals completed the survey. In the 2009-2010 season, 38.2% had both the seasonal and the pandemic vaccine, 22.1% had had only the seasonal, and 4.7% only the pandemic vaccine. The strongest predictor of not receiving the pandemic vaccine was not having had seasonal vaccinations in that year or the previous year. Those who had not received the pandemic vaccine were more often female; nurses; under 45; denied contact with at-risk groups; and had negative beliefs about the vaccine effectiveness and little concern for getting the disease, being infected at work, or passing it on to patients. It would be prudent to direct preventive campaigns not only at individuals at risk of catching flu but also at health professionals with a negative view of flu vaccine, with a particular focus on nurses, who have a key role in recommending flu vaccine.

Cost effectiveness of influenza vaccination in patients with acute coronary syndrome in Korea

BACKGROUND

Influenza can cause cardiovascular abnormalities by inappropriately activating the coagulation cascade. Therefore, influenza vaccination is important because it decreases the risk of hospitalization for and mortality associated with heart disease. In particular, it reduces the occurrence of major adverse cardiovascular events (MACEs) in acute coronary syndrome (ACS) patients. Our study aimed to estimate the disease burden of MACEs and its related direct and indirect costs in ACS patients.

METHODS

We estimated the direct and indirect cost of MACEs in ACS patients using a probabilistic model and the Health Insurance Review and Assessment (HIRA)-National Patient Sample (NPS) database. The effect of the influenza vaccination on the rate of MACE in ACS patients was determined using a previous systematic review and meta-analysis.

RESULTS

Our study included 682,258 ACS patients obtained from the 2013 NPS database. According to our model, influenza vaccination would prevent 16,514 MACE-related hospitalizations and 2764 premature deaths in Korea per year. The overall reduction in costs would be $86.2 million per year from a societal perspective. Based on the results of sensitivity analysis, most of the estimated values were in the dominant area.

CONCLUSIONS

Our findings show that influenza vaccination in ACS patients is highly cost effective in terms of lowering the cost of hospitalization and premature death due to MACE. Therefore, influenza vaccination is recommended as a means of relieving the clinical and socioeconomic burdens associated with ACS.

Influenza Vaccination Coverage and Its Associated Factors among North Korean Defectors Living in the Republic of Korea

This study aimed to examine influenza vaccination coverage of North Korean defectors (NKD) in the Republic of Korea (Korea) and explore the factors affected the vaccination coverage. Total 378 NKD were analyzed. Four Korean control subjects were randomly matched by age and gender from the Korea National Health and Nutrition Examination Survey V (n = 1,500). The adjusted vaccination coverage revealed no statistical difference between the defectors group and indigenous group (29.1% vs. 29.5%, P = 0.915). In the aged under 50 group, the vaccination coverage of NKD was higher than that of Korean natives (37.8% vs. 25.8%, P = 0.016). However in the aged 50 yr and over group, the vaccination coverage of North Korean defectors was lower than that of the natives (28.0% vs. 37.6%, P = 0.189). Even the gap was wider in the aged 65 yr and over group (36.4% vs. 77.8%, P = 0.007). Gender and medical check-up experience within 2 yr showed association with the vaccination coverage of NKD. Influenza vaccination coverage of aged defectors' group (aged 50 yr and over) was lower than indigenous people though overall vaccination coverage was similar. Further efforts to increase influenza vaccination coverage of this group are needed.

Immunizations against respiratory infections in children in primary health care in poland: coverage and delays

Pneumococcal infections, pertussis, and influenza are vaccine-preventable diseases. The aim of this study was to determine vaccine coverage and compliance with the dosage regimen among children in Poland. We performed a retrospective chart analysis of 1,356 children in a large primary healthcare establishment. The complete primary pertussis vaccination, 3 doses in the first year of life, was administered to 1,310/1,356 patients (96.6 %). The self-paid combined acellular vaccine was given in 55.2 % of children. The first dose of the pertussis vaccine was administered in a timely manner to 67.1 % of children. The self-paid pneumococcal vaccine was administered in 499/1,356 (36.8 %) children. In 46.1 % of them immunization started within the first 6 months of life; in 12.6 % aged 7-11 months, in 12.6 % aged 12-23 months, and in 28.7 % aged over 24 months. The dosage regimen was compliant in 49.2 % of patients. Only 3.5 % of patients were immunized against both pneumococci and influenza. Compliance with the Polish immunization program should be increased by reducing the number of injections and the cost of vaccines. Education is essential to facilitate simultaneous administration of vaccines during one visit and to prepare the parents for judicious decision-making when it comes to vaccinations.

Design and implementation of a combined influenza immunization and tuberculosis screening campaign with simulation modelling

RATIONALE, AIMS AND OBJECTIVES

Design and implement a concurrent campaign of influenza immunization and tuberculosis (TB) screening for health care workers (HCWs) that can reduce the number of clinic visits for each HCW.

METHOD

A discrete-event simulation model was developed to support issues of resource allocation decisions in planning and operations phases.

RESULTS

The campaign was compressed to100 days in 2010 and further compressed to 75 days in 2012 and 2013. With more than 5000 HCW arrivals in 2011, 2012 and 2013, the 14-day goal of TB results was achieved for each year and reduced to about 4 days in 2012 and 2013.

CONCLUSION

Implementing a concurrent campaign allows less number of visiting clinics and the compressing of campaign length allows earlier immunization. The support of simulation modelling can provide useful evaluations of different configurations.

[Strategies to improve influenza vaccination coverage in Primary Health Care]

INTRODUCTION

Vaccination coverage reached in adults is insufficient, and there is a real need for new strategies.

OBJECTIVE

To compare strategies for improving influenza vaccination coverage in persons older than 64 years.

PATIENTS AND METHODS

New strategies were introduced in our health care centre during 2013-2014 influenza vaccination campaign, which included vaccinating patients in homes for the aged as well as in the health care centre. A comparison was made on vaccination coverage over the last 4 years in 3 practices of our health care centre: P1, the general physician vaccinated patients older than 64 that came to the practice; P2, the general physician systematically insisted in vaccination in elderly patients, strongly advising to book appointments, and P3, the general physician did not insist.

RESULTS

These practices looked after P1: 278; P2: 320; P3: 294 patients older than 64 years. Overall/P1/P2/P3 coverages in 2010: 51.2/51.4/55/46.9% (P=NS), in 2011: 52.4/52.9/53.8/50.3% (P=NS), in 2012: 51.9/52.5/55.3/47.6% (P=NS), and in 2013: 63.5/79.1/59.7/52.7 (P=.000, P1 versus P2 and P3; P=NS between P2 and P3). Comparing the coverages in 2012-2013 within each practice P1 (P=.000); P2 (P=.045); P3 (P=.018). In P2 and P3 all vaccinations were given by the nurses as previously scheduled. In P3, 55% of the vaccinations were given by the nurses, 24.1% by the GP, 9.7% rejected vaccination, and the remainder did not come to the practice during the vaccination period (October 2013-February 2014).

CONCLUSIONS

The strategy of vaccinating in the homes for the aged improved the vaccination coverage by 5% in each practice. The strategy of "I've got you here, I jab you here" in P1 improved the vaccination coverage by 22%.

Influenza vaccination of primary healthcare physicians may be associated with vaccination in their patients: a vaccination coverage study

Background

To assess the contribution of physician-related factors, especially their influenza vaccine status, in the vaccination coverage of their patients.

Methods

A study of vaccination coverage was carried out in Spain in 2011–12. The dependent variable (vaccination coverage in patients aged ≥65 years) was obtained from regional records. Information was gathered on the vaccination of physicians through an anonymous web survey. We compared the vaccination coverage of patients with the vaccination of their physicians using the Student t test. Associations were determined using a multilevel regression model.

Results

The coverage in patients aged ≥ 65 years was 56.3% and was higher (57.3%) in patients whose physician had been vaccinated than in those whose physician had not (55.2%) (p = 0.008). In the multilevel regression model, vaccination of the physician was associated (p = 0.049) with vaccination of their patients after controlling for the effects of age (p = 0.046), region (p = 0.089), and opinions on the effectiveness of the vaccine (p = 0.013).

Conclusions

Vaccination of physicians together with their opinions on the effectiveness of the vaccine may be a predictor of vaccination coverage in their patients. Further studies are required to confirm this.

Electronic supplementary material

The online version of this article (doi:10.1186/s12875-015-0259-0) contains supplementary material, which is available to authorized users.

[Factors associated with influenza immunization in primary care health workers]

OBJECTIVE

To identify the influenza vaccination coverage in healthcare workers in primary care and to determine the factors associated with vaccination (2013-2014 season).

METHODS

A cross-sectional study was carried out among 287 healthcare workers who completed a questionnaire that included questions about knowledge, beliefs and attitudes to influenza and vaccination. We estimated the vaccine coverage and identified the variables associated with vaccination of healthcare workers by using non-conditional logistic regression models.

RESULTS

The participation rate was 47.2%. Vaccination coverage was 60.3% and was higher in workers older than 55 years, women and pediatricians. The factors associated with healthcare worker vaccination were the perception that vaccination confers protection (aOR: 11.1; 95%CI: 3.41-35.9) and the perception that it is effective (aOR: 7.5; 95%CI: 0.9-59.3). No association was found between receiving the vaccine and knowledge of influenza or vaccination. However, an association was found with prescribing vaccination to pregnant women, to persons older than 65 years, and to immunosuppressed individuals.

CONCLUSIONS

Strategies should be designed to increase coverage, based on changing negative attitudes of healthcare workers to vaccination.

[Influenza vaccination coverage in children with risk conditions in Catalonia]

INTRODUCTION

Influenza vaccination is recommended in Catalonia in children older than 6 months with risk conditions for developing flu-related complications. The aim of this study is to determine influenza vaccine coverage in children with risk conditions and their association with socio-demographic factors and medical variables.

MATERIAL AND METHOD

Descriptive cross-sectional study of children with risk conditions for developing influenza complications (aged between 6months and 15years old) assigned to Primary Health Care centers in Catalonia at the beginning of the 2011-2012 influenza vaccination campaign. The information on vaccination status and study variables were obtained from data registered on electronic health records by primary care teams. The relationship between influenza vaccination and demographic and medical variables was analyzed using bivariate analysis and a multiple logistic regression model.

RESULTS

Influenza vaccination coverage was 23.9%. Variables associated with influenza vaccination were: age 2years or older (aOR: 1.6 [1.4-1.7] in children 3-5years old; 1.8 [1.7-2.0] in those 6-10 years, and 2.2 [2.0 -2.4] in children ≥11years]); male sex (aOR: 1.1 [1.0-1.1]); foreign nationality (aOR: 1.2 [1.2-1.3]); age-appropriate immunization according to the systematic immunization schedule (aOR: 3.3 [2.8-3.8]); more than one visit to the primary care physician (5 or more visits) (aOR: 4.1 [3.8-4.4]), and more than one risk condition (3 or more conditions) (aOR: 2.5 [1.6-3.9]).

DISCUSSION

Compared to other countries, influenza vaccination coverage among children with risk conditions is low in our study. Strategies to improve coverage should be implemented.

Coverage and predictors of vaccination against 2012/13 seasonal influenza in Madrid, Spain: analysis of population-based computerized immunization registries and clinical records

We aim to determine 2012–13 seasonal influenza vaccination coverage. Data were analyzed by age group and by coexistence of concomitant chronic conditions. Factors associated with vaccine uptake were identified. We also analyze a possible trend in vaccine uptake in post pandemic seasons.

We used computerized immunization registries and clinical records of the entire population of the Autonomous Community of Madrid, Spain (6 284 128 persons) as data source.

A total of 871 631 individuals were vaccinated (13.87%). Coverage for people aged ≥ 65 years was 56.57%. Global coverage in people with a chronic condition was 15.7% in children and 18.69% in adults aged 15–59 years.

The variables significantly associated with a higher likelihood of being vaccinated in the 2012–13 campaign for the age groups studied were higher age, being Spanish-born, higher number of doses of seasonal vaccine received in previous campaigns, uptake of pandemic vaccination, and having a chronic condition.

We conclude that vaccination coverage in persons aged &lt;60 years with chronic conditions is less than acceptable. The very low coverage among children with chronic conditions calls for urgent interventions. Among those aged ≥60 years, uptake is higher but still far from optimal and seems to be descending in post-pandemic campaigns. For those aged ≥65 years the mean percentage of decrease from the 2009/10 to the actual campaign has been 12%.

Computerized clinical and immunization registers are useful tools for providing rapid and detailed information about influenza vaccination coverage in the population.

Negative trends from 2008/9 to 2011/12 seasons in influenza vaccination coverages among high risk subjects and health care workers in Spain

OBJECTIVES

We aim to describe influenza vaccination coverage for the Spanish population across four consecutive campaigns (2008/2009 to 2011/2012). The data was analyzed by high risk groups and health care workers (HCWs). Also, coverage trends were analyzed to assess uptake in post-pandemic seasons.

METHODS

We used data from two nation-wide representative health surveys namely the 2009/10 European Health Interview Survey for Spain (N=22,188) and the 2011-12 Spanish National Health Survey (N=21,007) Influenza vaccination status was self-reported. We analyzed influenza vaccine coverage by age, sex, number of chronic conditions, being a heath care worker (HCWs) and nationality. Time trends for campaigns among high risk groups were estimated by a multivariate logistic regression model.

RESULTS

We analyzed data from 43,072 subjects aged ≥ 16 years. As a whole, coverage decreased by 3.31% (22.57-19.26%) between the 2008/2009 and 2011/2012 campaigns with a significant decreasing trend (OR 0.92; 95% CI: 0.90-0.94). Coverage in people under 60 years with a chronic disease decreased significantly (OR 0.92: 95% CI: 0.85-0.99) during the analyzed period from 21.02% in 2008/2009 to 17.40% in 2011/2012. Among HCWs, the highest influenza vaccination coverage was achieved in 2009/2010 (31.08%) in the latest campaign coverage has almost halved (17.88%). For the 2011/2012 season and for all age groups the variables associated with a higher probability of having received the influenza vaccine were older age and presence of associated chronic conditions. Among those aged ≥ 60 years, immigrants had lower uptake (OR 0.60; 95% CI: 0.32-0.99).

CONCLUSIONS

Seasonal influenza vaccine uptake rates in the recommended target groups in Spain are unacceptably low and seem to be decreasing in the post pandemic seasons. Further studies are necessary to precisely identify reasons for non-compliance and barriers to influenza vaccination. Meanwhile urgent strategies to improve seasonal vaccination uptake must be discussed and implemented.

Seasonal influenza vaccination coverage rate of target groups in selected cities and provinces in China by season (2009/10 to 2011/12)

Background

The objectives of the survey were to identify the level of influenza vaccination coverage in China in three influenza seasons 2009/10 to 2011/12, and to find out potential predictors for seasonal influenza vaccination.

Methods

In September and October 2011, representative urban household telephone surveys were conducted in five provinces in China with a response rate of 6%. Four target groups were defined for analysis: 1) children ≤5 years old; 2) elderly persons aged ≥60 years old; 3) health care workers (persons working in the medical field) and 4) chronically ill persons.

Results

The overall mean vaccination rate was 9.0%. Among the four target groups, the rate of vaccination of children aged ≤5 years old (mean = 26%) was highest and the rate of elderly people aged ≥60 years old (mean = 7.4%) was the lowest, while the rates of persons who suffer from a chronic illness (mean = 9.4%) and health care workers (9.5%) were similar. A subsidy for influenza vaccination, age group, health care workers, suffering from a chronic illness and living in Eastern China were independent significant predictors for influenza vaccination.

Conclusions

The seasonal influenza vaccination coverage rates among urban populations in selected cities and provinces in China were far below previously reported rates in developed countries. Influenza vaccination coverage rates differed widely between different target groups and provinces in China. Subsidy policy might have a positive effect on influenza vaccination rate, but further cost-effectiveness studies, as well as the vaccination rate associated factors studies are still needed to inform strategies to increase coverage.

Trends in influenza vaccine coverage among primary healthcare workers in Spain, 2008-2011

OBJECTIVE

To evaluate trends in seasonal influenza vaccination coverage in primary healthcare workers (PHCWs) in Spain between 2008 and 2011.

METHODS

We made an anonymous web survey of PHCWs in 2012. Information on attitudes towards and knowledge of influenza vaccine, and immunization in previous seasons was collected. Self-reported vaccination coverage and factors related to vaccination continuity were analysed.

RESULTS

Of 5433 workers contacted, 2625 (48.3%) responded to the survey: 47.0% were general practitioners, 10.3% paediatricians and 42.7% nurses. Their reported vaccination rates from seasons 2008-2009 to 2011-2012 decreased over time: 58.4%, 57.4%, 53.2% and 49.3% (linear trend, p < 0.001). Among workers vaccinated in any previous season, 70.2% were vaccinated again in 2011-2012, compared with 5.2% among those not previously vaccinated (p < 0.001). Continuity of vaccination increased with age and with the worker or cohabitant having a major chronic condition. Vaccination was higher in workers who recognized vaccination as effective and those worried about being infected or infecting patients.

CONCLUSION

Influenza vaccination coverage in PHCWs has declined, especially after the pandemic. Intensive interventions are needed to change this trend. Knowledge of vaccination should be reinforced by stressing the effectiveness of the vaccine and the risks of influenza for workers and patients.

Sex differences in prophylaxis and therapeutic treatments for viral diseases

The intensity and prevalence of viral infections are typically higher in males than in females. In contrast, disease outcome can be worse for females. Males and females also differ in their responses to prophylaxis and therapeutic treatments for viral diseases. In response to vaccines against herpes viruses, hepatitis viruses, influenza viruses, and others, females consistently mount higher humoral immune responses and experience more frequent and severe adverse reactions than males. Males and females also differ in the absorption, metabolism, and clearance of antiviral drugs. The pharmacological effects, including toxicity and adverse reactions, of antiviral drugs are typically greater in females than males. The efficacy of antiviral drugs at reducing viral load also differs between the sexes, with antiviral treatments being better at clearing HIV and hepatitis C virus in females, but showing greater reduction of herpes simplex virus and influenza A virus loads in males. Biological variables, including hormone and genes, as well as gender-specific factors related to access and compliance to drug regimens must be considered when evaluating male-female differences in responses to treatments for viral diseases. Clinicians, epidemiologists, and basic biomedical scientists should design experiments that include both males and females, develop a priori hypotheses that the sexes will differ in their responses to and the outcome of vaccines and antiviral treatments, and statistically analyze outcome data by sex. Knowledge that the sexes differ in response to prophylaxis and therapeutic treatments for viral diseases should influence the recommended course of treatment differently for males and females.

Influenza vaccination coverage rate in children: reasons for a failure and how to go forward

Based on an increasingly extensive literature expressing the large interest in the field, this paper gives an overview of different aspects of influenza prevention in children. It relies on paradoxes. First, the heaviest part of the burden is well demonstrated in the youngest infants by numerous epidemiological data elsewhere. On the contrary, with older children, the prevention by influenza vaccines is more efficacious-without notable side effects. Second, the available TIV vaccines are 60 years old and the requests of registration and regulation of vaccines have evolved. There is a specific need in children: it is time to re-discuss the pragmatic utilization of influenza vaccines (full dose in the youngest patient? More flexibility regarding the interval between the two required doses in vaccine-naïve children), and to change from a compassionate use to a targeted research and adapted vaccines considering the limits of TIV in the youngest children. Third, influenza virus transmission is the highest in children in semi-close communities (day-care centers, schools), diffusing to households and more largely to the population. A restricted policy on high risk groups (roughly 10% in a pediatric population, all medical conditions including asthma, for whom influenza vaccine coverage is a 15-75% range) is far below the estimated threshold of 45% coverage rate to limit the virus circulation by an indirect impact during seasonal epidemics. Fourth, public health decisions in the vaccination field are usually taken from top to bottom. The pandemic A/H1N1 has toughly demonstrated that "forgetting" about the perception and expectations of the public and the parents nearly created conflicts and at least a strong resistance impeding the quality of a program worked on for a long time ahead. Fifth, and not the least, HCPs are pivotal in influenza vaccination mostly trusted by the parents. Too often, they are not backed by a national and clear support and they need to reinforce their knowledge on the disease and the vaccines.

Mechanisms of sex disparities in influenza pathogenesis

Epidemiological evidence from influenza outbreaks and pandemics reveals that morbidity and mortality are often higher for women than men. Sex differences in the outcome of influenza are age-dependent, often being most pronounced among adults of reproductive ages (18-49 years of age) and sometimes reflecting the unique state of pregnancy in females, which is a risk factor for severe disease. Small animal models of influenza virus infection illustrate that inflammatory immune responses also differ between the sexes and impact the outcome of infection, with females generating higher proinflammatory cytokine and chemokine responses and experiencing greater morbidity and mortality than males. Males and females also respond differently to influenza vaccines, with women initiating higher humoral immune responses but experiencing more adverse reactions to seasonal influenza vaccines than men. Small animal models further show that elevated immunity following vaccination in females leads to greater cross-protection against novel influenza viruses in females compared with males. Sex steroid hormones, including estradiol and testosterone, as well as genetic differences between the sexes may play roles in modulating sex differences in immune responses to influenza virus infection and vaccination. Future studies must elucidate the pathways and cellular responses that differ between the sexes and determine how best to use this knowledge to inform public health policy-makers about prophylaxis and therapeutic treatments of influenza virus infections to ensure adequate protection in both males and females.

Antibody responses and cross protection against lethal influenza A viruses differ between the sexes in C57BL/6 mice

A mouse model was used to determine if protective immunity to influenza A virus infection differs between the sexes. The median lethal dose of H1N1 or H3N2 was lower for naïve females than males. After a sublethal, primary infection with H1N1 or H3N2, females and males showed a similar transient morbidity, but females generated more neutralizing and total anti-influenza A virus antibodies. Immunized males and females showed similar protection against secondary challenge with a homologous virus, but males experienced greater morbidity and had higher lung viral titers after infection with a lethal dose of heterologous virus. Females develop stronger humoral immune responses and greater cross protection against heterosubtypic virus challenge.

Vaccination coverage with seasonal and pandemic influenza vaccines in children in France, 2009-2010 season

For a number of years now, GEIG, the Groupement d'Expertise et d'Information sur la Grippe (Influenza Expertise and Information Group) has conducted surveys to monitor seasonal trivalent vaccine uptake in France in adults. During the H1N1 pandemic in 2009, this survey was conducted to determine vaccination uptake for both pandemic and seasonal vaccines. An additional specific questionnaire was used to collect data on vaccination in children under 15 years of age. This additional study was carried out because pandemic vaccination (PV) was offered to the French population and children were listed as a priority target group by the national health authorities, whereas seasonal trivalent inactivated vaccines (TIV) are not recommended in children in France. Overall, we collected 2443 questionnaires on children, including children with underlying conditions (9.2%) for whom TIV vaccination was recommended. Overall, 17.9% of children (438/2443) received at least one shot of PV, compared to 3.4% (83/2443) who received at least one shot of TIV. PV uptake was statistically different between non at-risk and at-risk children (366/2218 [16.5%] vs. 71/225 [31.8%], p<0.0001). This difference was even more significant in the subgroup of children with severe underlying diseases (42.7%, p<0.0001). This confirms that despite the low overall PV uptake in the French population (9%), the specific recommendation for PV for children increased vaccine uptake in this specific population, suggesting that the disease burden of influenza in children is recognised by both practitioners and parents. The next few years will tell us whether TIV uptake in children increases as a consequence of the specific recommendations made for children during the 2009 pandemic wave, or whether it will return to the very low level of 3.4% observed before the pandemic.

Seasonal influenza vaccine uptake in Germany 2007/2008 and 2008/2009: results from a national health update survey

In 2008/2009 a nationwide cross-sectional telephone survey was conducted to assess, among other health-relevant parameters, seasonal influenza vaccination coverage. Data from 21,262 household-interviews representative of the adult population in Germany were collected and analyzed. In seasons 2007/2008 and 2008/2009, vaccine uptake in individuals aged ≥60 years was 57% and 55% and in individuals with underlying chronic diseases 44% and 42%. Living in the eastern part of Germany, higher age, and medium household income level were independently associated with higher vaccine uptake in both target groups. Healthcare workers were significantly less frequently (21.9% in 2007/2008; 20.4% in 2008/2009) vaccinated than the general population (30.8% and 28.1%). Special effort must be undertaken to develop immunization strategies for improved vaccine uptake in target groups, especially in healthcare workers.

[Flu vaccination in the elderly]

Seasonal flu is a very serious public health problem in the elderly due to its morbidity and mortality and financial and social costs arising from this. The aim of this review is to describe the magnitude and importance of seasonal flu in this population group, and its prevention by means of vaccination. For this reason, an updated account of the composition of the vaccine, its dosage and administration route, vaccine safety and the evaluation of the immunogenicity and effectiveness of vaccination. There is variation between different countries and official organisations on the age at which flu vaccination must be established in the elderly. New flu vaccination strategies need to be introduced, to further improve flu vaccination cover in Spain.

Influenza vaccine coverage among children under the age of 5 years in Poland during 2004-2008

Introduction

Influenza is a considerable health problem all over the world. The most important group for influenza vaccination are children: the highest attack rate during community out-breaks of influenza can be found among school-aged children or their family members; children bear a considerable risk for complications due to influenza, leading to an increased need for healthcare resources (including hospitalization). The high level of vaccine coverage among school children could provide protection against influenza among households and could reduce mortality rates among older individuals.

Objective

The aim of this study was to estimate the influenza vaccine coverage among children younger than 5 years and to find any trends in influenza vaccine coverage in 2004-2008 in Poland.

Material and methods

Official data (number of administrated vaccines and the age of vaccinated individuals) collected by the National Institute of Hygiene, the National Institute of Public Health, and the Central Statistical Office in Poland were analyzed. This data are reported by physicians and collected from reports prepared annually by the Sanitary-Epidemiological Stations at a local level. The vaccine coverage rate was calculated as a percentage of vaccinated individuals among all children under the age of 5 years.

Results

The influenza vaccine coverage among children younger than 5 years varied from 1% (2007 and 2008) to 1.9% (2005). The proportion of vaccinated children aged less than 5 compared with the total number of flu shots administrated irrespective of age also varied from 1.4% (2007) to 2% (2005).

Conclusions

The influenza vaccination coverage among Polish children aged less than 5 years is low and has persisted at the same level. More educational activities directed both to patients (parents) and healthcare workers would be needed to improve a general knowledge about influenza vaccination benefits among young children.

Trends in hospital admissions due to asthma in north-west Spain from 1995 to 2007

PURPOSE

Asthma is the most common chronic disease in childhood. Hospital admissions in the child population appear to be reducing in different populations.

METHODS

We have retrospectively analysed admissions into hospitals in our region due to asthma in a 0 to 14 years population, between the years 1995 and 2007. The age, sex, date of admission, and length of hospital stay of each patient was recorded and analysed.

RESULTS

A total of 9106 admissions (64% males) have been included. A gradual trend towards a reduction in admissions is observed during the period analysed. There were more admissions in 1996, with 2.91 per thousand inhabitants, gradually reducing to 1.33 per thousand in 2007. There were more admissions in May and between September and December, being less frequent in July and August. The mean stay in this period was 4.18 days, which was stable during the whole period of the study. Older children tended to have a longer hospital stay.

CONCLUSIONS

Our study shows that admissions due to childhood asthma tend to be decreasing, particularly due to younger males, with no change in the length of hospital stay. Asthma exacerbations seemed to be associated with infections and exposure to allergens.

Gender influence in influenza vaccine uptake in Spain: time trends analysis (1995-2006)

This study aims to analyze gender differences in influenza vaccine coverage and predictors of vaccine uptake in Spain from year 1995 to 2006. We used data obtained from the Spanish National Health Surveys (NHSS) conducted in 1995, 1997, 2001, 2003 and 2006. Only subjects for whom the vaccine was recommended in Spain (age >or=65 years and <65 years with an associated chronic condition) during the entire study period were analyzed. Influenza vaccination status was self-reported. Independent variables included: year of survey, age, marital status, educational level, size of town, physician visits and chronic conditions. The study population included 26,653 (15,973 women and 10,680 men) individuals and 54.9% (CI 95% 54.3-55.5) were vaccinated. Vaccination coverage was higher among men than women in each and all of the NHSS analyzed. Positive predictors of vaccine uptake were the same among women and men including: higher age, being married, lower educational level, "Physician visits in last four weeks"; and the presence of associated chronic condition. Time trends 1995/1997-2006 showed that the coverage has improved for women (OR 1.12 CI 95% 1.09-1.16) and men (OR 1.11 CI 95% 1.06-1.15). Over the whole study period men had 12% greater probability of having received the vaccine. We conclude that in Spain there are significant gender differences in influenza vaccine uptake with lower coverage among women. These differences have remained throughout all years studied. We suggest that possible explanations for the lower uptake among women could include less social support, differences in the health status and provider bias.

Oseltamivir for treatment of influenza in infants less than one year: a retrospective analysis

BACKGROUND

Influenza causes proportionately more hospitalizations and deaths in infants in their first year of life than in older children. Oseltamivir is an effective treatment for childhood influenza, but few data are available in infants <1 year.

METHODS

Medical records of infants <1 year admitted to hospital during the influenza seasons 2003-2007 were retrospectively analyzed to evaluate clinical presentation, and safety and outcome with oseltamivir therapy. Eligible infants were those with fever (>38 degrees C), influenza-like symptoms of sudden onset, positive rapid influenza test and parental consent, who received oseltamivir within 48 hours of the start of symptoms. Infants vaccinated against influenza or receiving immunosuppressants were excluded.

RESULTS

In 157 evaluable infants (mean age 6.3 [SD 3.2] months; 86 boys), the most common presenting symptoms other than fever were rhinitis, pharyngitis, cough, feeding difficulties, and otitis media. During treatment, additional symptoms were observed in 78 (50%) infants; most of these were gastrointestinal (vomiting and diarrhea) and of mild intensity. Fever resolved in 128 (82%) infants within 36 hours of starting oseltamivir (136 [87%] within 48 hours). Complications were recorded in 84 patients (54%), the most serious of which were meningitis in 1 infant (1%), pneumonia in 9 (6%), and otitis media in 2 (1%). Twenty infants received antibiotics for secondary infections (10 [6%] before admission).

CONCLUSIONS

The clinical presentation of influenza and outcome of oseltamivir treatment in infants <1 year was similar to that previously reported in older children, but mild gastrointestinal symptoms were common.

The Xs and Y of immune responses to viral vaccines

The biological differences associated with the sex of an individual are a major source of variation, affecting immune responses to vaccination. Compelling clinical data illustrate that men and women differ in their innate, humoral, and cell-mediated responses to viral vaccines. Sex affects the frequency and severity of adverse effects of vaccination, including fever, pain, and inflammation. Pregnancy can also substantially alter immune responses to vaccines. Data from clinical trials and animal models of vaccine efficacy lay the groundwork for future studies aimed at identifying the biological mechanisms that underlie sex-specific responses to vaccines, including genetic and hormonal factors. An understanding and appreciation of the effect of sex and pregnancy on immune responses might change the strategies used by public health officials to start efficient vaccination programmes (optimising the timing and dose of the vaccine so that the maximum number of people are immunised), ensure sufficient levels of immune responses, minimise adverse effects, and allow for more efficient protection of populations that are high priority (eg, pregnant women and individuals with comorbid conditions).

Determinants of influenza immunization uptake in Canadian youths

OBJECTIVE

To describe rate and determinants of influenza vaccination among Canadian youths.

METHODS

We conducted an analysis of cross-sectional data from the Canadian Community Health Survey (CCHS) cycle 3.1 collected by Statistics Canada in 2005. This is a population-based survey collecting information pertaining to the Canadian population health status, health care utilization and health determinants. The CCHS 3.1 included 12,170 respondents age 12-17 years old who answered questions pertaining to influenza vaccination. We used multivariate logistic regression to estimate the odds of having received the influenza vaccination in the last 12 months, adjusting for potential confounders.

RESULTS

Less than a quarter of Canadian youth reported receiving the influenza vaccination in the previous year. The most common reason for not getting the vaccination was "did not think it was necessary" (40.82%). Having chronic illness, and being an immigrant was significantly associated with a higher odds of receiving the influenza vaccination, while having an allergy and increasing frequency of alcohol drinking was associated with lower odds of receiving influenza vaccination. Smoking status acted as an effect modifier for many variables except for immigration status.

CONCLUSIONS

Influenza vaccination rate in Canadian youths is low. Judgement values on its necessity are a major factor in the decision to receive influenza vaccination. Strategies to involve youths in influenza vaccination programs and campaigns will be essential to achieve better national coverage.

Influenza vaccination coverage among Spanish children, 2006

OBJECTIVES

Traditionally, influenza is not considered to be a serious disease in healthy children. However, for vulnerable populations, such as young children and those with chronic medical conditions, influenza can lead to serious complications and even death. This study aimed to assess vaccination coverage among Spanish children under 16 years of age in 2006, and to describe the factors associated with vaccination.

STUDY DESIGN

Cross-sectional survey.

METHODS

In total, 8851 records of children included in the Spanish National Health Survey for 2006 were analysed. The reply ('yes' or 'no') to the question: 'Did you have a flu shot in the latest campaign?' was used as a dependent variable. Influenza vaccine coverage was calculated as the percentage of individuals aged 6 months to 16 years whose parents reported that they had been vaccinated against influenza in the most recent campaign. The influence of sociodemographic variables on vaccination and the presence of associated chronic diseases (asthma and/or diabetes) were also analysed.

RESULTS

Vaccination coverage among Spanish children in 2006 was 6.82%: 19.43% in children with associated conditions (asthma and/or diabetes), and 5.81% in healthy children. The only factor significantly associated with influenza vaccination in children with associated conditions was household income; children with a lower household monthly income were more likely to have been vaccinated against influenza than children with a higher household monthly income (odds ratio 1.96). In children for whom vaccination is not indicated, the probability of being vaccinated against influenza was greater in those whose parents were not university graduates.

CONCLUSION

Influenza vaccination coverage in Spanish children is low. Socio-economic inequalities continue to be a factor at the time of vaccination.