Factors associated to repeated influenza vaccination in the Portuguese adults with chronic conditions

Predicting future vaccination habits: The link between influenza vaccination patterns and future vaccination decisions among old aged adults in China

BACKGROUND

Annual influenza vaccination is crucially recommended for the elderly to maintain humoral immunity. Insufficient coverage requires us to understand the determinants of their influenza behaviors and how these patterns impact vaccination choices.

METHODS

Data from 540 Beijing residents aged over 65 were collected through interviews, capturing vaccination history and sociodemographic details. Individual influenza vaccination records from 2016 to 2020 were obtained from China's Immunization Information Systems. A latent class model identified three vaccination patterns. Multinomial logistic regression assessed relative risk ratios (RRRs) for vaccination based on sociodemographic factors. Vaccination patterns were used to predict future vaccination likelihood.

RESULTS

The analysis revealed three groups: sporadically vaccinated (63.33%), occasionally vaccinated (18.71%), and frequently vaccinated (17.96%). Factors associated with frequent vaccination included age over 70 (RRR = 2.81), lower income (RRR = 0.39), higher vaccine hesitancy (RRR = 3.10), multiple chronic conditions (RRR = 2.72), and rural residence (RRR = 2.48). The frequently vaccinated group was more likely to sustain regular vaccination habits in subsequent years compared to the occasionally vaccinated group.

CONCLUSIONS

Only 17.96% of Beijing's older population exhibited a consistent influenza vaccination pattern. Older age, rural residency, and chronic diseases correlated with repeated influenza vaccination. Segmenting the population based on past vaccination behavior can aid in designing targeted interventions to improve vaccination rates.

Factors associated to influenza vaccination among hospital's healthcare workers in the Autonomous Community of Madrid, Spain 2021-2022

Influenza vaccination (IV) aims primarily to protect high-risk groups against severe influenza-associated disease and death. It is recommended in Spain for high-risk groups, including Healthcare workers (HCWs). However, vaccination uptake has been consistently below desirable levels. The objective of this study were to evaluate influenza vaccination coverage using data from the regional vaccination registry, during 2021-2022 season, among HCWs in public hospitals in Autonomous Community of Madrid (CAM) and to explore factors associated with influenza vaccination. We conducted a cross-sectional study using administrative data retrieved from the Regional Department of Health data repositories. A multilevel logistic regression model was designed to estimate Level 1 (individual) and Level 2 (contextual) variables that are associated with HCẂs vaccination. The study population was HCWs from 25 public hospitals in CAM who were active during the period of the influenza 2021-2022 vaccination campaign. The global influenza vaccination coverage (IVC) was 52.1 %. All study Level 1 variables were significantly associated with vaccine uptake. Greater IVC is associated with individual characteristics: female (OR1.14; 95 %CI 1.09-1.19), older age 59-69 years old (OR1.72; 95 %CI 1.60-1.84), born in Spain, medical staff, more than one high-risk condition (OR1.24; 95 %CI 1.10-1.40; respectively) and vaccinated in two previous campaigns (OR25.64; 95 %CI 24.27-27.09). IVC was highest among HCWs celiac disease (65.5 %) followed by diabetes mellitus (65.1 %) and chronic inflammatory disease (64.3 %). The hospital where the study subject worked also showed an effect on the vaccination uptake, although Level 2 variable (hospital complexity) was not positively associated. IVC in HCWs remains suboptimal. These findings may prove useful to tailor strategies to reach specific groups. It is recommended to delve into the identification of factors associated with the HCWs workplace that may have a positive impact on IV.

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.

Are younger COPD patients adequately vaccinated for influenza and pneumococcus?

Influenza and pneumococcal pneumonia are major causes of increased morbidity and mortality among elderly and COPD patients. Vaccines against influenza and pneumococcus are recommended for COPD patients according to GOLD 2020 guidelines to prevent serious illnesses. Despite their high morbidity and mortality burden, the vaccination coverage rates remain far below the WHO's recommended targets. In Greece, there are insufficient data on influenza and pneumococcal immunization rates among younger COPD patients. This study investigated whether COPD patients under the age of 65 are adequately vaccinated against influenza and pneumococcus and the factors that influence vaccination rates. 1100 individuals at 22 Primary Health Centers in Central Greece participated in a two-year spirometry monitoring program. Face-to-face interviews were used to collect information regarding demographics, smoking status, comorbidities, respiratory illnesses in the previous two years, and influenza and pneumococcal vaccination coverage from all COPD patients. 117 patients aged 40-65 years old were diagnosed with COPD and 80.3% were males. Only 40.2% of them had received influenza and 32.5% pneumococcus vaccinations. Age, advanced stage of COPD, years on COPD diagnosis, respiratory infection within the previous two years, comorbidity, and smoking cessation are all positively connected with influenza and pneumococcus vaccine coverage in younger COPD patients. Gender, education level, and marital status did not affect influenza and pneumococcus vaccination rates. These vaccination rates among younger COPD patients demonstrate the need for increased awareness and knowledge about the advantages of immunizations in lowering morbidity and mortality.

Low Levels of Influenza Vaccine Uptake among the Diabetic Population in Spain: A Time Trend Study from 2011 to 2020

(1) Background: In this work, we aim to describe influenza vaccine uptake among the diabetic population in Spain to assess the time trend from 2011 to 2020 and identify predictors of vaccine uptake among diabetes patients. (2) Methods: We conducted a descriptive cross-sectional study using the European Health Interview Survey for Spain (2014 and 2020) and the Spanish National Health Surveys (2011 and 2017). The independent variables analysed included socio-demographic characteristics, health-related variables and lifestyle variables. We matched each participant with diabetes with a non-diabetic participant based on age, sex, place of residence and year of survey. (3) Results: The overall coverage among diabetic adults was 52.1% compared to 40.6% for matched participants without diabetes (p < 0.01). The vaccine uptake among adults with diabetes was 52.6% in 2011, 54.38% in 2014 and 53.4% in 2017. The adjusted OR of having been vaccinated in 2020, with respect to 2011, was not significant at 0.87 (95% CI: 0.72–1.06). Factors such as being male, higher age, being affected by respiratory disease or cancer and being physically active were identified as positive predictors for influenza vaccination uptake, while smoking was a negative predictor. (4) Conclusions: The influenza vaccine uptake is below desirable levels among the adult diabetic population in Spain and has not improved from 2011 to 2020. More efforts should be made to increase influenza vaccine uptake in this high-risk group, especially for women, those aged 18–64 years, without other high-risk conditions and smokers.

No effect modification of influenza virus vaccine effectiveness by age or chronic condition was observed in the 2010/11 to 2017/18 seasons

PURPOSE

Most European influenza vaccine strategies target individuals at higher risk of complications, which include, among others, individuals aged ≥65 years and with chronic conditions. These individuals not only have a high-risk of post-infection complications but also could have lower capacity of acquiring adequate vaccine-induced protection. As such, chronic conditions and age could modify the effect of vaccines. This study aimed at assessing the potential effect modification of influenza vaccine effectiveness (IVE) by age and chronic conditions.

METHODS

We used eight-season data from the Portuguese vaccine effectiveness study. Every season, physicians at primary care units recruited patients with influenza-like illness. Clinical data and swabs were collected for Reverse Transverse Polymerase Chain Reaction (RT-PCR) detection of influenza. Trivalent inactivated IVE was estimated as 1 - odds ratio (OR) of being vaccinated in cases (RT-PCR positive for influenza) versus negative controls. ORs were obtained using a multivariable conditional logistic regression model, paired by week of onset within each season. Confounders were assessed by designing a specific causal diagram. Age (< 65 or ≥65 years) and chronic conditions (diabetes, cardiovascular disease, chronic renal disease, chronic hepatic disease, obesity, chronic respiratory disease, and congenital or acquired immunodeficiency) were studied as effect modifiers by including an interaction term in the regression models. Significance was established at 5%.

RESULTS

Point estimates indicate a higher IVE in the chronic condition strata compared to that in the no chronic condition strata. Regarding age, different results were obtained considering the virus type and (sub)type. When comparing the ≥65 years with the <65 years of age strata, we observed a higher IVE against A(H1N1)pdm09, an equal IVE against A(H3N2) and a lower IVE against B virus. However, all interaction terms were statistically insignificant, and this may be due to a small sample size.

CONCLUSION

The potential effect modification of age or chronic condition was not observed within our study.

Assessing Vaccine Protection for Older Adults with Diabetes: A Systematic Review

Immunosenescence and comorbidities increase the susceptibility of older adults with diabetes mellitus (DM) to vaccine-preventable diseases, hospitalization, disability, or death. This systematic review synthesizes research on protecting older adults with DM during pandemics, exploring vaccine safety, tolerance, and vaccination uptake by older adults in anticipation of seasonal influenza outbreaks during the current COVID-19 threat. Addressed were: (a) age-related factors influencing the effectiveness of vaccines against infectious disease in older adults; (b) vaccine safety, tolerance, effectiveness for older persons with DM; and (c) issues affecting older adults accepting immunization recommendations. Medline and CINAHL databases yielded 214 studies with 43 meeting inclusion criteria (32 descriptive and 11 controlled trials). Findings show altered glycemic control stimulates proinflammatory mediators, increasing infection risk, vaccines, and annual revaccinations safely reduce hospitalization rates, mortality outcomes, without affecting glycemic control. However, vaccines fail to evoke optimal antibody responses in older adults. Unawareness, fear of side effects, tend to lower vaccination participation.

Increased influenza vaccination rates in patients with autoimmune rheumatic diseases during the Covid-19 pandemic: a cross-sectional study

To assess non-compliance and potential changes in seasonal flu vaccination coverage before and during the Covid-19 pandemic in patients with autoimmune rheumatic diseases (ARDs). Consecutive patients with ARDs followed-up in 2 tertiary hospitals were telephone-interviewed (December 12–30, 2020) regarding seasonal flu vaccination during the 2019/20 and 2020/21 time periods. Self-reported disease flares that occurred after flu vaccination, as well as reasons for non-vaccination were recorded. One thousand fifteen patients were included. The rate of flu vaccination increased from 76% before to 83% during the COVID-19 pandemic (p = 0.0001). The rate of self-reported disease flares was < 1% among vaccinated patients. Reasons for not vaccination in both periods, respectively, included: ‘was not recommended by their rheumatologists’ (35.0vs.12.2%, p < 0.0001), ‘did not feel that they would have any benefit’ (36.9 vs. 32.6%), felt unsafe to do so (27.5 vs. 30.2%), or other reasons (18.9 vs. 23.8%). By multivariate analysis, age [OR = 1.03 (95% CI 1.02–1.04)] vs. [1.04 (95% CI 1.02–1.05)] and treatment with biologics [OR = 1.66 (95% CI 1.22–2.24) vs. [1.68 (95% CI 1.19–2.38)] were independent factors associated with vaccination in both periods. These findings, although are temporally encouraging, emphasize the need for continuous campaigns aiming at increasing patients’ and physicians’ awareness about the benefits of vaccination.

The coverage of influenza and pneumococcal vaccination among kidney transplant recipients and waiting list patients: A cross-sectional survey in Denmark

BACKGROUND

To characterize level and predictors of influenza and pneumococcal vaccine uptake among Danish kidney transplant recipients (KTR) and kidney transplant waiting list patients (WLP).

METHODS

A cross-sectional survey based on self-reported vaccine uptake including WLP and KTR ≤ 1½ years post transplantation. Descriptive statistics and logistic regression analyses identifying factors associated with influenza vaccine uptake in the latest season were performed.

RESULTS

A total of 220 participants were included in the study, 54% KTR and 46% WLP. Self-reported influenza vaccine uptake in the latest season was overall 41.8%. Uptake of influenza vaccine on any prior season apart from the latest season was 53.2% and significantly higher among WLP than KTR (P = .007). Pneumococcal vaccine uptake was only 4% overall. The only factor positively associated with influenza vaccine uptake in the latest season was any prior influenza vaccine uptake (OR 5.79, CI95 2.44-13.76) (P < .001). Recommendations given by other persons (non-physician) were negatively associated with receiving the influenza vaccination in the latest season (OR 0.34, CI95 0.13-0.92) (P = .03). Reasons for not being vaccinated were primarily lack of information, perception of own good health, and fear of adverse reactions.

CONCLUSIONS

Influenza and pneumococcal vaccine uptakes were suboptimal among Danish WLP and KTR. Increased awareness about guidelines and physicians´ education are warranted.

Influenza coverage rates in subjects with chronic heart diseases: results obtained in four consecutive immunisation seasons in the Local Health Unit of Ferrara (North Italy)"

Background

Seasonal influenza epidemics yearly affects 5–15% of the world’s population, resulting in 3–5 million serious cases and up to 650,000 deaths. According to the 2017–2019 Italian National Immunisation Plan, free immunisation is offered to the categories at increased risk of experience the complications of the infection (over 65 years old subjects, pregnant women and individuals with underlying conditions, including chronic heart diseases). Rising evidence suggests that influenza can trigger adverse cardiovascular events therefore the vaccination is recommended for secondary prevention of cardiovascular diseases. Despite this, the influenza coverage rate in subjects with chronic heart disease is underestimated.

Methods

The study investigated the coverage rate in four consecutive influenza seasons (from 2011/2012 to 2014/2015) in subjects that benefit from exemption from paying healthcare costs for chronic heart disease living in Local Health Unit (LHU) of Ferrara (Italy), comparing the databases of exemptions and immunisations.

Results

The levels of influenza vaccine uptake were unstable, reaching the 50.3% in 2011/2012 immunisation season and falling to 42.2% in the following year. Coverage rates increased with increasing age, without achieving the 75% target, neither in over 65 years old subjects. The logistic regression analysis showed that influenza coverage rates were statistically significant different (p < 0.0001, 0.003 only for category of disease in 2011/2012 immunisation season) according to age, district of residence, category of chronic heart disease and length of exemption, but not influenced by gender.

Conclusions

The recommendation of influenza immunisation was weakly followed in individuals with chronic heart diseases. A collaboration between cardiologists, GPs, scientific societies and patient associations could successfully support influenza vaccine uptake.

Understanding influenza vaccination among Portuguese elderly: the social ecological framework

This study intended to identify and quantify the social ecological model (SEM) levels associated to seasonal IV uptake in the Portuguese elderly population. Data from the 2014 National Health Survey was restricted to individuals aged 65+ years (n = 5669). Twenty-three independent variables were allocated to the SEM levels: individual, interpersonal, organizational, community and policy. Sex stratified and age adjusted analysis using Poisson regression were performed for each level and for a fitted full model. Relative reduction in pseudo R magnitude measured marginal contribution of each level. For men and women, older groups (85+ vs. 65–69; men, PR = 1.59 and women, PR = 1.56); having 3+ chronic conditions (men, PR = 1.39 and women, PR = 1.35); previous 4 weeks GP and outpatient visits were associated to higher IV uptake. For men, only 2 SEM levels were associated (individual and organizational) while for women the community level was also relevant. Main marginal contribution came from individual (17.9% and 16.3%) and organizational (30.7% and 22.7%) levels. This study highlights the importance of individual characteristics, access and use of health care services for the IV uptake and the sex differential behaviour.

Impact of national influenza vaccination strategy in severe influenza outcomes among the high-risk Portuguese population

Background

All aged individuals with a chronic condition and those with 65 and more years are at increased risk of severe influenza post-infection complications. There is limited research on cases averted by the yearly vaccination programs in high-risk individuals. The objective was to estimate the impact of trivalent seasonal influenza vaccination on averted hospitalizations and death among the high-risk population in Portugal.

Methods

The impact of trivalent seasonal influenza vaccination was estimated using vaccine coverage, vaccine effectiveness and the number of influenza-related hospitalizations and deaths. The number of averted events (NAE), prevented fraction (PF) and number needed to vaccinate (NVN) were estimated for seasons 2014/15 to 2016/17.

Results

The vaccination strategy averted on average approximately 1833 hospitalizations and 383 deaths per season. Highest NAE was observed in the ≥65 years population (85% of hospitalizations and 95% deaths) and in the 2016/17 season (1957 hospitalizations and 439 deaths). On average, seasonal vaccination prevented 21% of hospitalizations in the population aged 65 and more, and 18.5% in the population with chronic conditions. The vaccination also prevented 29% and 19.5% of deaths in each group of the high-risk population. It would be needed to vaccinate 3360 high-risk individuals, to prevent one hospitalization and 60,471 high-risk individuals to prevent one death.

Conclusion

The yearly influenza vaccination campaigns had a sustained positive benefit for the high-risk population, reducing hospitalizations and deaths. These results can support public health plans toward increased vaccine coverage in high-risk groups.