Differential uptake of herpes zoster vaccination associated with socioeconomic status: A population-based study in Stockholm County, Sweden

Comparison of rates of dementia among older adult recipients of two, one, or no vaccinations

Background

Multiple types of vaccinations are associated with lower risk for dementia, but it is not known if receiving more than one vaccination type is associated with a greater decrease in incident dementia as compared with receiving only one type. We determined if dementia risk is lowest in patients who receive both herpes zoster (HZ) and tetanus, diphtheria, pertussis (Tdap) vaccinations as compared with receipt of only one or the other type of vaccination.

Methods

Primary analysis in a Veterans Health Administration (VA) cohort was replicated in private sector medical claims data. Eligible patients were ≥65 years of age and free of dementia for 2 years prior to baseline (VHA n = 80,070; MarketScan n = 129,200). At index, patients either had both HZ and Tdap, only HZ, only Tdap, or neither vaccination. Confounding was controlled with generalized boosted propensity scores and inverse probability of treatment weighting. Competing risk (VHA) and Cox proportional hazard (MarketScan) models estimated the association between vaccination status and incident dementia.

Results

VHA patients' mean age was 76.8 ± 7.6 years, 4.4% were female and 90.9% were White, and MarketScan patients' mean age was 70.5 ± 5.9 and 65.4% were female. In both cohorts, having both HZ and Tdap vaccinations compared with no vaccination was significantly associated with lower dementia risk (VHA HR = 0.50; 95% CI: 0.43–0.59; MarketScan HR = 0.58; 95% CI: 0.38–0.89). In both cohorts, compared with neither vaccination, patients with only one or the other vaccination types had a significantly lower risk for dementia. Incident dementia was lower in patients with both vaccinations versus only one vaccination type.

Conclusions and Relevance

Receiving two types of vaccinations versus one type was associated with lower dementia risk. Vaccinations may have non‐specific associations with incident dementia. Low cost and accessible, common adult vaccinations may be an overlooked intervention for reducing dementia risk.

Impact of herpes zoster vaccination on incident dementia: A retrospective study in two patient cohorts

Background

Herpes zoster (HZ) infection increases dementia risk, but it is not known if herpes zoster vaccination is associated with lower risk for dementia. We determined if HZ vaccination, compared to no HZ vaccination, is associated with lower risk for incident dementia.

Methods and findings

Data was obtained from Veterans Health Affairs (VHA) medical records (10/1/2008–9/30/2019) with replication in MarketScan® commercial and Medicare claims (1/1/2009-12/31/2018). Eligible patients were ≥65 years of age and free of dementia for two years prior to baseline (VHA n = 136,016; MarketScan n = 172,790). Two index periods (either start of 2011 or 2012) were defined, where patients either had or did not have a HZ vaccination. Confounding was controlled with propensity scores and inverse probability of treatment weighting. Competing risk (VHA) and Cox proportional hazard (MarketScan) models estimated the association between HZ vaccination and incident dementia in all patients and in age (65–69, 70–74, ≥75) and race (White, Black, Other) sub-groups. Sensitivity analysis measured the association between HZ vaccination and incident Alzheimer’s dementia (AD). HZ vaccination at index versus no HZ vaccination throughout follow-up. VHA patients mean age was 75.7 (SD±7.4) years, 4.0% were female, 91.2% white and 20.2% had HZ vaccination. MarketScan patients mean age was 69.9 (SD±5.7) years, 65.0% were female and 14.2% had HZ vaccination. In both cohorts, HZ vaccination compared with no vaccination, was significantly associated with lower dementia risk (VHA HR = 0.69; 95%CI: 0.67–0.72; MarketScan HR = 0.65; 95%CI:0.57–0.74). HZ vaccination was not related to dementia risk in MarketScan patients aged 65–69 years. No difference in HZ vaccination to dementia effects were found by race. HZ vaccination was associated with lower risk for AD.

Conclusions

HZ vaccination is associated with reduced risk of dementia. Vaccination may provide nonspecific neuroprotection by training the immune system to limit damaging inflammation, or specific neuroprotection that prevents viral cytopathic effects.

Acceptance of pneumococcal vaccination in older adults: A general population-based survey

BACKGROUND

Pneumococcal infection is a leading cause of disability and death globally. The Hong Kong Government has launched two programmes for pneumococcal vaccination - The Vaccination Subsidy Scheme (VSS) and the Government Vaccination Programme (GVP). This study aimed to examine the enabling factors, obstacles and perception of pneumococcal vaccination, and their association with its uptake in a general Chinese population.

METHODS

We performed a population-based, telephone survey in the general public aged 65 or above via simple random sampling. A validated survey based on the Health Belief Model (HBM) was used. Their socio-demographic information; history of previous participation in the GVP or VSS; and self-perceived health status were captured. Binary logistic regression models were constructed to examine the factors independently associated with vaccination.

RESULTS

A total of 1,000 respondents were enrolled in the study, with 402 (40.2%) respondents having intention to join the GVP/VSS in 12 months. Respondents with long-term medical consultant and medication (adjusted odds ratios [aOR] = 1.541, 95% confidence interval (CI): 1.008-2.356, p = 0.046); high levels of perceived susceptibility of infections (aOR = 3.624, 95 %CI: 2.318-5.665, p < 0.001); high levels of perceived benefits of vaccine (aOR = 1.699, 95 %CI: 1.153-2.504, p < 0.001); recommendations from government (aOR = 8.025, 95 %CI: 4.771-13.497, p < 0.001) or physicians (aOR = 7.399, 95 %CI: 3.472-15.764, p = 0.008); and high levels of self-efficacy (aOR = 3.045, 95 %CI: 1.458-6.362, p = 0.003) were more likely to have intention to participate in the vaccination programme.

CONCLUSIONS

The acceptance rate of pneumococcal vaccination programme remained suboptimal in the population. The government and physicians should be involved in the promotion of pneumococcal vaccination and GVP/VSS by increasing perceived benefits and self-efficacy, and reducing barriers towards vaccination among the target population. More studies are required to confirm our findings in other settings.

Lower Risk for Dementia Following Adult Tetanus, Diphtheria, and Pertussis (Tdap) Vaccination

BACKGROUND

Adult vaccinations may reduce risk for dementia. However, it has not been established whether tetanus, diphtheria, pertussis (Tdap) vaccination is associated with incident dementia.

METHODS

Hypotheses were tested in a Veterans Health Affairs (VHA) cohort and replicated in a MarketScan medical claims cohort. Patients were at least 65 years of age and free of dementia for 2 years prior to index date. Patients either had or did not have a Tdap vaccination by the start of either of the 2 index periods (2011 or 2012). Follow-up continued through 2018. Controls had no Tdap vaccination for the duration of follow-up. Confounding was controlled using entropy balancing. Competing risk (VHA) and Cox proportional hazard (MarketScan) models estimated the association between Tdap vaccination and incident dementia in all patients and age subgroups (65-69, 70-74, and ≥75 years).

RESULTS

VHA patients were, on average, 75.6 (SD ± 7.5) years of age, 4% female, and 91.2% were White. MarketScan patients were 69.8 (SD ± 5.6) years of age, on average and 65.4% were female. After controlling for confounding, patients with, compared to without, Tdap vaccination had a significantly lower risk for dementia in both cohorts (VHA: hazard ratio [HR] = 0.58; 95% confidence interval [CI]:0.54-0.63 and MarketScan: HR = 0.58; 95% CI:0.48-0.70).

CONCLUSIONS

Tdap vaccination was associated with a 42% lower dementia risk in 2 cohorts with different clinical and sociodemographic characteristics. Several vaccine types are linked to decreased dementia risk, suggesting that these associations are due to nonspecific effects on inflammation rather than vaccine-induced pathogen-specific protective effects.

Outpatient healthcare utilization and prescribing patterns for herpes zoster in United States adults

Little is known about health resource utilization and treatment patterns for herpes zoster (HZV) after the introduction of HZV virus vaccination. The objective of this study is to characterize trends in HZV utilization, racial disparities, and treatment patterns in the United States. Data from the 1993-2015 National Ambulatory Medical Care Survey were analyzed, including 15,400,000 weighted primary acute HZV visits in adults. Overall, the weighted frequency (95% confidence interval) of HZV visits increased from 1993-1998 to 2007-2015 (1,269,815 [565,455-1,974,175]-8,017,911 [6,424,491-9,611,331], P = 0.0001). HZV visits were associated with African-American (38.8% [35.8-41.7%] vs. 8.2% [7.4-9.0%]) and Hispanic race/ethnicity (12.6% [6.6-18.5%] vs. 8.0% [7.3-8.5%]), public insurance (42.7% [36.6-49.2%] vs. 33.7% [32.2-35.2%]) in comparison with all other visits. Oral antiviral agents were prescribed in 64.3% (58.1-70.1%) of HZV visits. HZV visits were associated with higher rates of opioid prescriptions compared to all other visits (18.4% [14.0-23.9%] vs. 6.1% [5.6-6.6%], P < 0.0001). The limitation is no data on HZV severity. HZV visits increased over time, even after introduction of HZV vaccines. There were significant racial/ethnic and healthcare disparities of, and high rates of opiate and corticosteroid prescriptions at HZV visits. Future efforts are needed to address these practice gaps, and encourage vaccination and evidence-based prescribing in HZV.

Knowledge about vaccines and vaccination in older people: Results of a national survey by the Italian Society for Gerontology & Geriatrics

BACKGROUND

There is wide variation among physicians in the level of knowledge regarding vaccines and vaccination. We sought to compare the level of vaccine knowledge between qualified specialists and postgraduate residents.

METHODS

A questionnaire designed ad hoc by a consensus group was circulated to the Directors of 51 geriatrics internship programs in Italy. It investigated demographics, information sources, knowledge about influenza, pneumonococcal and herpes zoster vaccines and target groups. The proportion of correct responders was compared between residents and qualified specialists, and between best (top quartile) and worst (bottom quartile) performers.

RESULTS

A total of 459 questionnaires were analyzed; 245 (53%) were females; 253 (55%) were qualified specialists, 206 (45%) were residents. Mean age was 40.3 (SD: 12.8) years, almost 60% worked in acute care wards. On average, 33% of patients asked for information about vaccination. Residents answered significantly better on 7 out of 18 questions, and numerically albeit non-statistically higher correct response rates on a further 8 questions. There were significantly more men among the poor performers (p < 0.001), and significantly more residents among the best performers (p < 0.001). Overall, the rates of correct answers were low, with >50% of correct responses achieved on only 5 out of 18 questions (27.8%); for 2 questions, <20% responded correctly.

CONCLUSIONS

Postgraduate residents in training have an overall better level of knowledge of vaccines, vaccination indications and practices than qualified specialists. This study provides avenues to develop targeted interventions to ensure health care providers are up to date and providing accurate information to patients.

Effectiveness of the herpes zoster vaccine Zostavax® in Stockholm County, Sweden

OBJECTIVE

The objective of this study was to estimate the effectiveness of the herpes zoster vaccine Zostavax in a cohort of vaccinated individuals in Sweden.

METHODS

The study is a retrospective population-based matched cohort study conducted with data from health care registers in Stockholm Country. Primary endpoints were new diagnosis of HZ after administration of Zostavax. Individuals above the age of 50 years and living in Stockholm County in 2013 were included into the study. Ten non-vaccinated individuals per vaccinated were included and randomized into the cohort. The non-vaccinated were matched on age at index date and gender.

RESULTS

Zostavax had an overall effectiveness (VE) of 34% (HR = 0.66, 95% CI: 0.55-0.78). When stratifying by age, 61-75 years was the only age group that showed a reduced risk of HZ (HR = 0.57; CI 0.44-0.73) compared to those that were non-vaccinated. As compared to the unvaccinated group, the VE was significant at days 180-359 (HR = 0.53; 95% CI 0.33-0.88), 360-539 (HR = 0.46; 95% CI 0.27-0.80) and at days 540-719 (HR = 0.56; 95% CI 0.35-0.90) after vaccination.

CONCLUSION

This is the first population-based study in Sweden studying the effectiveness of HZ vaccination. Our findings are well in-line with previous studies, however studies addressing the longitudinal efficacy and effectiveness of Zostavax are still required.