Asthma and influenza vaccination in elderly hospitalized patients: Matched case-control study in Spain

The Cost of Seasonal Influenza: A Systematic Literature Review on the Humanistic and Economic Burden of Influenza in Older (≥ 65 Years Old) Adults

INTRODUCTION

Adults aged ≥ 65 years contribute a large proportion of influenza-related hospitalizations and deaths due to increased risk of complications, which result in high medical costs and reduced health-related quality of life (HRQoL). Although seasonal influenza vaccines are recommended for older adults, the effectiveness of current vaccines is dependent on several factors including strain matching and recipient demographic factors. This systemic literature review aimed to explore the economic and humanistic burden of influenza in adults aged ≥ 65 years.

METHODS

An electronic database search was conducted to identify studies assessing the economic and humanistic burden of influenza, including influenza symptoms that impact the HRQoL and patient-related outcomes in adults aged ≥ 65 years. Studies were to be published in English and conducted in Germany, France, Spain, and Italy, the UK, USA, Canada, China, Japan, Brazil, Saudi Arabia, and South Africa.

RESULTS

Thirty-eight studies reported on the economic and humanistic burden of influenza in adults aged ≥ 65 years. Higher direct costs were reported for people at increased risk of influenza-related complications compared to those at low risk. Lower influenza-related total costs were found in those vaccinated with adjuvanted inactivated trivalent influenza vaccine (aTIV) compared to high-dose trivalent influenza vaccine (TIV-HD). Older age was associated with an increased occurrence and longer duration of certain influenza symptoms.

CONCLUSION

Despite the limited data identified, results show that influenza exerts a high humanistic and economic burden in older adults. Further research is required to confirm findings and to identify the unmet needs of current vaccines.

Review of Vaccination Recommendations in Guidelines for Non-Communicable Diseases with Highest Global Disease Burden among Adults 75 Years Old and Above

This scientific review paper explores international and country-specific healthcare guidelines for non-communicable diseases with the highest burden among individuals aged 75 years and above. The study aims to identify the best vaccination practices and standardize healthcare practices to improve vaccination adherence in this vulnerable population. Given that older people are more prone to infectious illnesses and have higher rates of morbidity and mortality, vaccinations are essential for disease prevention. Despite the proven efficacy of vaccinations, adherence has plateaued in recent years, partly due to a lack of accessibility, public education, and variability in disease-specific guidelines. This paper highlights the need for a more robust and standardized international vaccination model to improve quality of life and reduce disability-adjusted life years among the elderly. The findings of this study call for further research to review the guidelines as more implementations are put in place, including non-English guidelines.

Seasonal Influenza Vaccine Effectiveness in People With Asthma: A National Test-Negative Design Case-Control Study

BACKGROUND

Influenza infection is a trigger of asthma attacks. Influenza vaccination can potentially reduce the incidence of influenza in people with asthma, but uptake remains persistently low, partially reflecting concerns about vaccine effectiveness (VE).

METHODS

We conducted a test-negative designed case-control study to estimate the effectiveness of influenza vaccine in people with asthma in Scotland over 6 seasons (2010/2011 to 2015/2016). We used individual patient-level data from 223 practices, which yielded 1 830 772 patient-years of data that were linked with virological (n = 5910 swabs) data.

RESULTS

Vaccination was associated with an overall 55.0% (95% confidence interval [CI], 45.8-62.7) risk reduction of laboratory-confirmed influenza infections in people with asthma over 6 seasons. There were substantial variations in VE between seasons, influenza strains, and age groups. The highest VE (76.1%; 95% CI, 55.6-87.1) was found in the 2010/2011 season, when the A(H1N1) strain dominated and there was a good antigenic vaccine match. High protection was observed against the A(H1N1) (eg, 2010/2011; 70.7%; 95% CI, 32.5-87.3) and B strains (eg, 2010/2011; 83.2%; 95% CI, 44.3-94.9), but there was lower protection for the A(H3N2) strain (eg, 2014/2015; 26.4%; 95% CI, -12.0 to 51.6). The highest VE against all viral strains was observed in adults aged 18-54 years (57.0%; 95% CI, 42.3-68.0).

CONCLUSIONS

Influenza vaccination gave meaningful protection against laboratory-confirmed influenza in people with asthma across all seasons. Strategies to boost influenza vaccine uptake have the potential to substantially reduce influenza-triggered asthma attacks.

Benefits of influenza vaccination on the associations between ambient air pollution and allergic respiratory diseases in children and adolescents: New insights from the Seven Northeastern Cities study in China

BACKGROUND

Little information exists on interaction effects between air pollution and influenza vaccination on allergic respiratory diseases. We conducted a large population-based study to evaluate the interaction effects between influenza vaccination and long-term exposure to ambient air pollution on allergic respiratory diseases in children and adolescents.

METHODS

A cross-sectional study was investigated during 2012-2013 in 94 schools from Seven Northeastern Cities (SNEC) in China. Questionnaires surveys were obtained from 56 137 children and adolescents aged 2-17 years. Influenza vaccination was defined as receipt of the influenza vaccine. We estimated air pollutants exposure [nitrogen dioxide (NO₂) and particulate matter with aerodynamic diameters ≤1 μm (PM₁), ≤2.5 μm (PM_2.5) and ≤10 μm (PM₁₀)] using machine learning methods. We employed two-level generalized linear mix effects model to examine interactive effects between influenza vaccination and air pollution exposure on allergic respiratory diseases (asthma, asthma-related symptoms and allergic rhinitis), after controlling for important covariates.

RESULTS

We found statistically significant interactions between influenza vaccination and air pollutants on allergic respiratory diseases and related symptoms (doctor-diagnosed asthma, current wheeze, wheeze, persistent phlegm and allergic rhinitis). The adjusted ORs for doctor-diagnosed asthma, current wheeze and allergic rhinitis among the unvaccinated group per interquartile range (IQR) increase in PM₁ and PM_2.5 were significantly higher than the corresponding ORs among the vaccinated group [For PM₁, doctor-diagnosed asthma: OR: 1.89 (95%CI: 1.57-2.27) vs 1.65 (95%CI: 1.36-2.00); current wheeze: OR: 1.50 (95%CI: 1.22-1.85) vs 1.10 (95%CI: 0.89-1.37); allergic rhinitis: OR: 1.38 (95%CI: 1.15-1.66) vs 1.21 (95%CI: 1.00-1.46). For PM_2.5, doctor-diagnosed asthma: OR: 1.81 (95%CI: 1.52-2.14) vs 1.57 (95%CI: 1.32-1.88); current wheeze: OR: 1.46 (95%CI: 1.21-1.76) vs 1.11 (95%CI: 0.91-1.35); allergic rhinitis: OR: 1.35 (95%CI: 1.14-1.60) vs 1.19 (95%CI: 1.00-1.42)]. The similar patterns were observed for wheeze and persistent phlegm. The corresponding p values for interactions were less than 0.05, respectively. We assessed the risks of PM₁-related and PM_2.5-related current wheeze were decreased by 26.67% (95%CI: 1.04%-45.66%) and 23.97% (95%CI: 0.21%-42.08%) respectively, which was attributable to influenza vaccination (both p for efficiency <0.05).

CONCLUSIONS

Influenza vaccination may play an important role in mitigating the detrimental effects of long-term exposure to ambient air pollution on childhood allergic respiratory diseases. Policy targeted at increasing influenza vaccination may yield co-benefits in terms of reduced allergic respiratory diseases.

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

BACKGROUND

Annual influenza vaccination has been recommended for persons with high-risk conditions since the 1960s. However, few estimates of influenza vaccine effectiveness (VE) for persons with high-risk conditions are available.

METHODS

Data from the U.S. Influenza Vaccine Effectiveness Network from 2012 to 2016 were analyzed to compare VE of standard-dose inactivated vaccines against medically-attended influenza among patients aged ≥6 months with and without high-risk medical conditions. Patients with acute respiratory illness were tested for influenza by RT-PCR. Presence of high-risk conditions and vaccination status were obtained from medical records. VE by influenza virus type/subtype and age group was calculated for patients with and without high-risk conditions using the test-negative design. Interaction terms were used to test for differences in VE by high-risk conditions.

RESULTS

Overall, 9643 (38%) of 25,369 patients enrolled during four influenza seasons had high-risk conditions; 2213 (23%) tested positive for influenza infection. For all ages, VE against any influenza was lower among patients with high-risk conditions (41%, 95% CI: 35-47%) than those without (48%, 95% CI: 43-52%; P-for-interaction = 0.02). For children aged <18 years, VE against any influenza was 51% (95% CI: 39-61%) and 52% (95% CI: 39-61%) among those with and without high-risk conditions, respectively (P-for-interaction = 0.54). For adults aged ≥18 years, VE against any influenza was 38% (95% CI: 30-45%) and 44% (95% CI: 38-50%) among those with and without high-risk conditions, respectively (P-for-interaction = 0.21). For both children aged <18 and adults aged ≥18 years, VEs against illness related to influenza A(H3N2), A(H1N1)pdm09, and influenza B virus infection were similar among those with and without high-risk conditions.

CONCLUSIONS

Influenza vaccination provided protection against medically-attended influenza among patients with high-risk conditions, at levels approaching those observed among patients without high-risk conditions. Results from our analysis support recommendations of annual vaccination for patients with high-risk conditions.