Influenza Vaccination Coverage Rate according to the Pulmonary Function of Korean Adults Aged 40 Years and Over: Analysis of the Fifth Korean National Health and Nutrition Examination Survey

All-Cause and Cause-Specific Mortality Attributable to Seasonal Influenza: A Nationwide Matched Cohort Study

BACKGROUND

Although influenza poses substantial mortality burden, most studies have estimated excess mortality using time-aggregated data. Here, we estimated mortality risk and population attributable fraction (PAF) attributed to seasonal influenza using individual-level data from a nationwide matched cohort.

METHODS

Individuals with influenza during four consecutive influenza seasons (2013-2017) (n = 5,497,812) and 1:4 age- and sex-matched individuals without influenza (n = 20,990,683) were identified from a national health insurance database. The endpoint was mortality within 30 days after influenza diagnosis. All-cause and cause-specific mortality risk ratios (RRs) attributed to influenza were estimated. Excess mortality, mortality RR, and PAF of mortality were determined, including for underlying disease subgroups.

RESULTS

Excess mortality rate, mortality RR, and PAF of all-cause mortality were 49.5 per 100,000, 4.03 (95% confidence interval [CI], 3.63-4.48), and 5.6% (95% CI, 4.5-6.7%). Cause-specific mortality RR (12.85; 95% CI, 9.40-17.55) and PAF (20.7%; 95% CI, 13.2-27.0%) were highest for respiratory diseases. In subgroup analysis according to underlying disorders, PAF of all-cause mortality was 5.9% (95% CI, 0.6-10.7%) for liver disease, 5.8% (95% CI, 2.9-8.5%) for respiratory disease, and 3.8% (95% CI, 1.4-6.1%) for cancer.

CONCLUSION

Individuals with influenza had a 4-fold higher mortality risk than individuals without influenza. Preventing seasonal influenza may lead to 5.6% and 20.7% reductions in all-cause and respiratory mortality, respectively. Individuals with respiratory disease, liver disease, and cancer may benefit from prioritization when establishing influenza prevention strategies.

Trends and factors associated with influenza vaccination in subjects with asthma: analysis of the Korea National Health and Nutrition Examination Survey between 2010 and 2019

BACKGROUND

Despite the importance of influenza vaccination, its rates in subjects with asthma are suboptimal, especially in the young population.

METHODS

Among 72,843 adults aged ⩾18 years from the Korea National Health and Nutrition Examination Survey conducted between 2010 and 2019, 1643 with asthma were included. The yearly trends and factors associated with influenza vaccination were analyzed in subjects with asthma. In addition, stratified analyses were performed by age group (<65 versus ⩾65 years).

RESULTS

During the study period, the overall influenza vaccination rate among subjects with asthma fluctuated from 51.0% to 64.3%, with a consistently higher vaccination rate in elderly subjects than in young subjects. Among young subjects with asthma, factors positively associated with influenza vaccination were female sex [adjusted odds ratio (aOR) = 1.66, 95% confidence interval (CI) = 1.11-2.49], current asthma being treated (aOR = 1.69, 95% CI = 1.14-2.50), history of pulmonary tuberculosis (aOR = 2.01, 95% CI = 1.04-3.87), and dyslipidemia (aOR = 1.86, 95% CI = 1.05-3.30). However, unmarried subjects showed an inverse relationship (aOR = 0.50, 95% CI = 0.34-0.75). In elderly subjects, unmarried status (aOR = 0.52, 95% CI = 0.29-0.94), being underweight (aOR = 0.29, 95% CI = 0.09-0.97), and having a low income (aOR = 0.42, 95% CI = 0.18-0.97) were factors negatively associated with influenza vaccination.

CONCLUSION

In the last 10 years, influenza vaccination rates have still been insufficient in subjects with asthma, particularly in young subjects. Considering the factors that are influencing the vaccination rates of young subjects, public policies to increase influenza vaccination rates in subjects with asthma need to be established urgently.

Secular trends and determinants of influenza vaccination uptake among patients with cardiovascular disease in Korea: Analysis using a nationwide database

Background

Influenza vaccination reduces cardiovascular events in patients with cardiovascular disease (CVD). Identifying the factors that affect influenza vaccination uptake can help improve the prognosis in patients with CVD. This study aimed to evaluate the secular trends of influenza vaccination uptake and factors associated with lack of vaccination in individuals with CVD.

Materials and methods

We analyzed the annual trends and factors associated with influenza vaccination among 3,264 patients with CVD, included from the Korea National Health and Nutrition Examination Survey which reflect the health and nutritional status of the nationwide population of Korea conducted between 2007/2008 and 2018/2019. We used a stratified, multistage sampling method.

Results

The influenza vaccination rate was greater in patients with CVD (53–74%) than in those without CVD (28–40%). Multivariable logistic regression analysis showed that age <50 years [odds ratio (OR), 16.22; 95% confidence interval (CI), 7.72–34.07], 50–64 years (OR, 6.71; 95% CI, 4.37–10.28), male sex (OR, 1.45; 95% CI, 1.14–1.65), and asthma (OR, 0.45; 95% CI, 0.22–0.92) were independently associated with a lack of influenza vaccination. Among patients aged <65 years, smoking (OR, 2.30; 95% CI, 1.31–4.04), college graduation status (OR, 1.81; 95% CI, 1.16–2.82), and hypertension (OR, 0.70; 95% CI, 0.51–0.95) were independently associated with influenza vaccination. For individuals aged 65years, there was no significant determinant of lack of vaccination.

Conclusion

In patients with CVD, a continuous increase in the secular trend of influenza vaccination was demonstrated in Korea. Young age, male sex, and non-asthma status were independently associated with lack of influenza vaccination uptake.

Evaluation of influenza vaccination coverage in Shanghai city during the 2016/17 to 2020/21 influenza seasons

Influenza is a common infectious disease resulting in substantial morbidity and mortality globally. The most effective strategy for preventing influenza is annual vaccination; however, the coverage rate of the influenza vaccine in Shanghai has not been well explored or reported. Therefore, this study aimed to determine coverage with the influenza vaccine and access trends in Shanghai city; data from Shanghai immunization information system was analyzed to estimate vaccination coverage during 2016–2017 through 2020–2021 influenza seasons. Vaccination coverage by age groups, immigration status, and districts was accessed. The influenza vaccination coverage (at least one dose) for 2016/2017 to 2020/2021 influenza seasons was 10.8‰ (95‰ CI: 10.7–10.8), 12.3‰ (95‰ CI: 12.3–12.4), 10.1‰ (95‰ CI: 10.0–10.1), 20.1‰ (95‰ CI: 20.0–20.2) and 50.8‰ (95‰ CI: 50.7–50.8) respectively. Although we found significantly higher vaccination coverage in females, children from 6 months to 17 years, and residents, it is still low in all subgroups of the population in Shanghai. Therefore, taking effective steps to promote influenza vaccination in Shanghai is recommended.

The role of health determinants in the influenza vaccination uptake among older adults (65+): a scope review

Background

Although the burden of influenza infection is the highest in older adults, vaccination coverage remains low, despite this age group being more vulnerable than others.

Aims

Given the current pandemic of SARS-CoV-2, it was the aim of this scope review to update knowledge on factors affecting seasonal influenza vaccine uptake among older adults to strengthen prevention approaches in the context of an overall burden of infectious diseases.

Methods

We searched bibliographic databases from 2012 to 2019. All studies reviewed one or more social determinant of health listed by WHO, or factors affecting the decision-making process whether to accept influenza vaccine or not.

Results

Overall, 44 studies were included, 41 determinants were extracted and summarized into six categories. Older age and constitutional factors including multiple chronic diseases as well as preventive lifestyle and frequent routine healthcare utilization positively affected vaccination uptake (VU). Living and working conditions are also researched determinants of influenza vaccine uptake. A small number of studies explored the role of social inclusion and system-based interventions.

Discussion and conclusions

This scope review provides a comprehensive overview on factors affecting seasonal influenza vaccination uptake among older citizens. The review also clearly shows gaps for evidence on system-based level or political strategies to improve vaccination uptake.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01793-3.

Barriers to influenza vaccination among different populations in Shanghai

BACKGROUND

Seasonal influenza vaccination coverage remains low in most areas of China. Its influencing factors and barriers in various populations receiving influenza vaccinations need to be well understood to promote vaccination.

METHODS

A cross-sectional survey was conducted with residents in 48 communities. Vaccination status in the 2018-2019 influenza season and reasons for or against vaccination were surveyed. The potential factors influencing vaccination uptake were determined using bivariate logistic regression.

RESULTS

In total, 1301 of the 11053 respondents received an influenza vaccine during the 2018-2019 season with a coverage rate of 11.8% (95% CI, 11.2-12.4). The vaccine coverage was highest among children (26.6%, 95%CI: 24.8-28.5), followed by adults (8.2%, 95%CI: 7.4-9.0) and elderly people (7.3%, 95%CI: 6.5-8.1) (p < .001). Those with chronic underlying conditions all had higher vaccine coverage than did those without for different groups (p < .001). Among the three groups, the most common reason for being unvaccinated was worrying about the side effects (45.0%), believing they were healthy and did not need to get vaccinated (42.2%), and lack of influenza vaccine awareness (48.3%). Low education level and lack of awareness were identified as predictors of low coverage rate.

CONCLUSION

Influenza vaccination coverage is low among different populations in Shanghai. Our study highlights the need for appropriate influenza vaccination strategies and programmes targeting different populations.

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.

Vaccination coverage with the pneumococcal and influenza vaccine among persons with chronic diseases in Shanghai, China, 2017

BACKGROUND

Adults with chronic conditions such as heart disease, diabetes, or lung disease are more likely to develop complications from a number of vaccine-preventable diseases, including influenza and pneumonia. In this study, we use the data from a chronic disease management information system in Shanghai to estimate vaccination coverage and characterize predictors of seasonal influenza and 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccination among people with chronic disease in Shanghai.

METHODS

The Shanghai Centers for Disease Control and Prevention have information systems related to chronic disease management, hospital records, and immunizations. Data from individuals with hypertension, diabetes and chronic obstructive pulmonary disease (COPD) were abstracted during July 2017. The main outcome was coverage of pneumococcal and influenza vaccination. Vaccination coverage was calculated across demographic groups. Significance in bivariate associations was assessed through Pearson's chi-square tests, and in multivariable models through logistic regression models with a forward stepwise method to select variables.

RESULTS

In the sample of 2,531,227 individuals ≥15 years, 22.8% were vaccinated for pneumonia from January 2013 to July 2017, and the vaccination coverage of influenza in the 2016/17 influenza season was 0.4%. Vaccination coverage was highest in those 70-79 and lowest in those younger than 60. Compared to urban areas, uptake in rural areas was higher for pneumonia vaccination (OR: 2.43, 95% CI: 2.41, 2.45), but lower for influenza vaccination (OR: 0.55, 95% CI: 0.51, 0.59). Having a greater number of chronic diseases was associated with higher likelihood of pneumonia vaccination (3 vs 1: OR: 1.68, 95% CI: 1.64, 1.71), but this relationship was not statistically significant for influenza vaccination.

CONCLUSIONS

We found low levels with of pneumococcal vaccination, and extremely low uptake of influenza vaccination among individuals with high risk conditions in Shanghai who should be priority groups targeted for vaccination. Interventions could be designed to target groups with low uptake - like younger adults, and individuals who have not yet retired.

Low coverage rate and awareness of influenza vaccine among older people in Shanghai, China: A cross-sectional study

Background: Older individuals are at high risk for morbidity and mortality due to influenza, and the most effective way to prevent influenza is yearly vaccination. In China, the influenza vaccine is not covered by the national Expanded Program on Immunization, and more evidence is needed about influenza vaccine usage among older individuals.

Objective: To determine the influenza vaccination coverage and its influencing factors, and understand barriers to older adults receiving influenza vaccinations in Shanghai, China.

Methods: A cross-sectional survey was conducted with residents aged 60 and older. Vaccination status in the 2016–17 influenza season and reasons for or against vaccination were surveyed. The vaccination coverage rates were adjusted by gender, age and community distribution, and potential factors influencing vaccination uptake were determined by bivariate logistic regression.

Results: In total, 253 of the 4417 respondents received an influenza vaccine during the 2016–17 season, yielding an adjusted coverage rate of 5.2% (95% CI, 4.5-5.8). The frequency of receiving the vaccine was higher for older individuals living with family/friends than that for those living alone (p < 0.05), and lower among individuals with chronic respiratory diseases (p < 0.05). Among unvaccinated respondents, lack of influenza vaccine awareness was the most common reason for being unvaccinated (48.3%, 2012/4164).

Conclusion: Influenza vaccination coverage is extremely low among older people in Shanghai, and lack of awareness of the influenza vaccine might be a potential barrier to vaccination. Our study highlights the need for an appropriate influenza vaccination strategy and program targeting the older population.

Influenza Vaccination Coverage Among Polish Patients with Chronic Diseases

Patients at a high-risk of severe influenza, because of their underlying health disorders, are recommended to receive a seasonal influenza vaccination. In Poland, influenza coverage rate in the general population is very low (3.4 %). However, there is little known about the coverage rate among high-risk patients. The aim of this study was to describe a general knowledge, perception, and influenza vaccination coverage rate among Polish patients with enhanced risk for influenza. We conducted a self-reported survey among 500 patients with chronic disorders: 120 pulmonary, 80 hemodialyzed, 100 thyroid cancer, and 200 cardiovascular patients. We found the following influenza vaccination coverage in the respective groups of patients: 58 % in pulmonary, 34 % in hemodialyzed, 32 % in cardiovascular, and 9 % in thyroid cancer patients. The difference between the coverage rate in pulmonary patients compared with the other risk groups was significant (p < 0.05). In pulmonary patients, the most important barrier for influenza vaccination was a lack of recommendations from healthcare workers, while a high awareness of influenza was the most powerful driver for vaccination (p < 0.05). We conclude that although the influenza vaccination coverage in Polish patients with chronic diseases is higher than that reported in the general population, this rate remains much below the recommended level and should be improved.