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

Clinical symptoms, comorbidities and health outcomes among outpatients infected with the common cold coronaviruses versus influenza virus

BACKGROUND

Common cold coronaviruses (ccCoVs) and influenza virus are common infectious agents causing upper respiratory tract infections (RTIs). However, clinical symptoms, comorbidities, and health effects of ccCoV infection remain understudied.

METHODS

A retrospective study evaluated 3,935 outpatients with acute upper RTI at a tertiary teaching hospital. The presence of ccCoV and influenza virus was determined by multiplex molecular assay. The demographic, clinical symptoms, and health outcomes were compared between patients with ccCoV (n = 205) and influenza (n = 417) infections. Multivariable logistic regression was employed to evaluate predictors and health outcomes over a one-year follow-up.

RESULTS

Sore throat, nasal discharge, headache, and myalgia were more predominant in ccCoV infection; fever was common in influenza. Most patients reported moderate symptoms severity (49.8% ccCoV, 56.1% influenza). Subsequent primary care visits with symptoms of RTI within a year were comparable for both infections (27.3% ccCoV vs. 27.6% influenza). However, patients with influenza reported increased primary care visits for non-RTI episodes and all-cause hospital admission. Baseline comorbidities were associated with increased primary care visits with symptoms of RTI in either ccCoV (adjusted odds ratio [aOR] 2.5; 95% confidence interval [CI] 1.1-5.9; P = 0.034) or influenza (OR 1.9; 95% CI 1.1-3.1; P = 0.017) infections, due probably to the dysregulation of the host immune response following acute infections. In patients infected with influenza infection, dyslipidemia was a predictor for subsequent primary care visits with symptoms of RTI (unadjusted OR 1.8; 95% CI 1.0-3.0; P = 0.040).

CONCLUSIONS

Both influenza and ccCoV infection pose significant disease burden, especially in patients with comorbidities. The management of comorbidities should be prioritized to mitigate poor health outcomes in infected individuals.

Postdischarge functional outcomes in older patients with acute heart failure in Japan: the Longevity Improvement & Fair Evidence study

BACKGROUND

The association between care needs level (CNL) at hospitalisation and postdischarge outcomes in older patients with acute heart failure (aHF) has been insufficiently investigated.

METHODS

This population-based cohort study was conducted using health insurance claims and CNL data of the Longevity Improvement & Fair Evidence study. Patients aged ≥65 years, discharged after hospitalisation for aHF between April 2014 and March 2022, were identified. CNLs at hospitalisation were classified as no care needs (NCN), support level (SL) and CNL1, CNL2-3 and CNL4-5 based on total estimated daily care time as defined by national standard criteria, and varied on an ordinal scale between SL&CNL1 (low level) to CNL4-5 (fully dependent). The primary outcomes were changes in CNL and death 1 year after discharge, assessed by CNL at hospitalisation using Cox proportional hazard models.

RESULTS

Of the 17 724 patients included, 7540 (42.5%), 4818 (27.2%), 3267 (18.4%) and 2099 (11.8%) had NCN, SL&CNL1, CNL2-3 and CNL4-5, respectively, at hospitalisation. One year after discharge, 4808 (27.1%), 3243 (18.3%), 2968 (16.7%), 2505 (14.1%) and 4200 (23.7%) patients had NCN, SL&CNL1, CNL2-3, CNL4-5 and death, respectively. Almost all patients' CNLs worsened after discharge. Compared to patients with NCN at hospitalisation, patients with SL&CNL1, CNL2-3 and CNL4-5 had an increased risk of all-cause death 1 year after discharge (hazard ratio [95% confidence interval]: 1.19 [1.09-1.31], 1.88 [1.71-2.06] and 2.56 [2.31-2.84], respectively).

CONCLUSIONS

Older patients with aHF and high CNL at hospitalisation had a high risk of all-cause mortality in the year following discharge.

Association of Statin Use with Dementia Risk Among Older Adults in Japan: A Nested Case-Control Study Using the LIFE Study

Background

Previous studies have shown a possible association between statin use and a decreased risk of dementia, but the association has not been sufficiently established, especially in the super-aging society of Japan.

Objective

This study aimed to determine the association between statin use and the risk of dementia among Japanese participants aged> =65 years old.

Methods

Data from the Longevity Improvement and Fair Evidence (LIFE) Study were utilized, including medical and long-term care (LTC) claim data from 17 municipalities between April 2014 and December 2020. A nested case-control study was conducted with one case matched to five controls based on age, sex, municipality, and year of cohort entry. We used a conditional logistic regression model to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results

This study included 57,302 cases and 283,525 controls, with 59.7% of the participants being woman. After adjusting for potential confounders, statin use was associated with a lower risk of dementia (OR, 0.70; 95% CI: 0.68-0.73) and Alzheimer's disease (OR: 0.66; 95% CI: 0.63-0.69). Compared with non-users, the ORs of dementia were as follows: 1.42 (1.34-1.50) for 1-30 total standardized daily dose (TSDD), 0.91 (0.85-0.98) for 31-90 TSDD, 0.63 (0.58-0.69) for 91-180 TSDD, and 0.33 (0.31-0.36) for >180 TSDD in dose-analysis.

Conclusions

Statin use is associated with a reduced risk of dementia and Alzheimer's disease among older Japanese adults. A low cumulative statin dose is associated with an increased risk of dementia, whereas a high cumulative statin dose is a protective factor against dementia.

Immune thrombocytopenic purpura and Guillain-Barré syndrome after 23-valent pneumococcal polysaccharide vaccination in Japan: The vaccine effectiveness, networking, and universal safety (VENUS) study

BACKGROUND

To address the lack of an active vaccine safety surveillance system in Japan, the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study was initiated in 2021 as a pilot system using existing health insurance claims data and vaccination records.

METHODS

This study evaluated the value of the VENUS study by assessing the incidence of immune thrombocytopenic purpura (ITP) and Guillain-Barré syndrome (GBS) following vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPSV23) using a self-controlled case series (SCCS) design.

RESULTS

Incidence rate ratios for ITP during 28-day and 42-day risk periods were 0.89 (95% confidence interval [CI], 0.12-6.4), and 0.58 (95% CI, 0.081-4.2), respectively. Neither was statistically significant. Incidence rate ratios could not be estimated for GBS due to the limited sample size.

CONCLUSION

The VENUS study can provide valuable insights to facilitate the establishment of an advanced vaccine monitoring system in Japan.

Development of a COVID-19 vaccine effectiveness and safety assessment system in Japan: The VENUS Study

Background

There are currently no COVID-19 vaccine assessment systems in Japan that allow for the active surveillance of both vaccinated and unvaccinated persons. Herein, we describe the development of Japan’s first COVID-19 vaccine effectiveness and safety assessment system with active surveillance capabilities.

Methods

The Vaccine Effectiveness, Networking, and Universal Safety (VENUS) Study was developed as a multi-source database that links four data types at the individual resident level: Basic Resident Register (base population information), Vaccination Record System (vaccination-related information), Health Center Real-time Information-sharing System on COVID-19 (HER-SYS; information on COVID-19 occurrence), and health care claims data (information on diagnoses, hospitalizations, diagnostic tests, and treatments). These data were obtained from four municipalities. Individual residents were linked across the data types using five matching algorithms based on names, birth dates, and sex; the data were anonymized after linkage. To ascertain the viability of the VENUS Study’s database for COVID-19 vaccine assessments, we examined the trends in COVID-19 vaccinations, COVID-19 cases, and polymerase chain reaction (PCR) test numbers. We also evaluated the linkage rates across the data types.

Results

Our multi-source database was able to monitor COVID-19 vaccinations, COVID-19 cases, and PCR test numbers throughout the pandemic. Using the five algorithms, the data linkage rates between the COVID-19 occurrence information in the HER-SYS and the Basic Resident Register ranged from 85·4% to 91·7%.

Conclusion

If used judiciously with an understanding of each data source’s characteristics, the VENUS Study can provide a viable data platform that facilitates active surveillance and comparative analyses for population-based research on COVID-19 vaccine effectiveness and safety in Japan.

Association of pneumococcal vaccination with cardiovascular diseases in older adults: The vaccine effectiveness, networking, and universal safety (VENUS) study

The protective effect of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) against cardiovascular disease has been investigated in the United States and Europe; however, its effect has not been fully established. This study aimed to investigate the protective effect of PPSV23 on cardiovascular events in adults aged ≥ 65 years. This population-based nested case-control study was conducted using the claims data and vaccine records between April 2015 and March 2020 from the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) Study. PPSV23 vaccination was identified using vaccination records in each municipality. The primary outcome was acute myocardial infarction (AMI) or stroke. The adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for PPSV23 vaccination were calculated using conditional logistic regression. Among 383,781 individuals aged ≥ 65 years, 5,356 and 25,730 individuals with AMI or stroke were matched with 26,753 and 128,397 event-free controls, respectively. Individuals who were PPSV23 vaccinated, compared with the unvaccinated individuals, had significantly lower odds of AMI or stroke events (aOR, 0.70 [95% CI, 0.62-0.80] and aOR, 0.81 [95% CI, 0.77-0.86], respectively). More recent PPSV23 vaccination was associated with lower odds ratios (AMI, aOR 0.55 [95% CI, 0.42-0.72] for 1-180 days and aOR 1.11 [95% CI, 0.84-1.47] for 720 days or longer; stroke, aOR 0.83 [95% CI, 0.74-0.93] for 1-180 days and aOR 0.90 [95% CI, 0.78-1.03] for 720 days or longer). Among Japanese older adults, individuals who were PPSV23 vaccinated, compared with unvaccinated individuals, had significantly lower odds of AMI or stroke events.

Enhancing the protection of influenza virus vaccines with BECC TLR4 adjuvant in aged mice

Influenza A virus (IAV) is a leading cause of respiratory disease worldwide often resulting in severe morbidity and mortality. We have previously shown that the Bacterial Enzymatic Combinatorial Chemistry (BECC) adjuvants, BECC438 and BECC470, formulated with an influenza virus hemagglutinin (HA) protein vaccine, offer greater protection from influenza virus challenge in mouse respiratory models using adult mice than standard HA:adjuvant combinations. In this study, we determined that immunization with HA + BECC adjuvants also significantly broadened the epitopes targeted on HA as compared with other adjuvants, resulting in increased titers of antibodies directed against the highly conserved HA stalk domain. Importantly, we demonstrate that BECC470 combined with an influenza virus HA protein antigen in a prime-only immunization regimen was able to achieve complete protection from challenge in a ~ 12-month-old mouse aged model. Together, this demonstrates the heightened protection provided by the BECC470 adjuvant in an influenza virus vaccine model and shows the enhanced immune response, as compared to other adjuvants elicited by the formulation of HA with BECC470.