case-control study
Religiosity has been linked to a wide range of health outcomes, with evidence for both benefits and harms.
Alleged positive effects
Many studies have found positive associations between religious involvement and physical and mental health, including lower mortality, better self-rated health and greater psychological well‑being. However, most of this literature is methodologically weak, with selection bias, poor control for confounders and selective reporting, so firm causal conclusions are difficult.
Religiosity and spirituality have frequently been associated with positive effects on mental health, such as higher levels of life satisfaction, meaning in life, hope, optimism and lower rates of depression, substance misuse and some forms of suicidal behaviour. Proposed mechanisms include social support from religious communities, promotion of coping resources, encouragement of health‑promoting behaviours and cognitive frameworks that help some people make sense of adversity.
In addition, observational studies have linked religious participation with positive effects on physical endpoints, such as reduced smoking, more moderate alcohol use and in some cases better cardiovascular outcomes and lower all‑cause mortality, though effect sizes are usually modest. Cross‑national analyses show that religious people sometimes report better self‑rated health, but these associations vary widely by country and are sensitive to socioeconomic and cultural context.onlinelibrary.
Alleged negative effects
Some aspects of religiosity might be harmful: religious struggles—such as feeling punished by God, spiritual discontent or conflict with religious communities—are consistently associated with higher levels of depression, anxiety and distress. Some studies also suggest that rigid or punitive religious beliefs can exacerbate guilt, internalized stigma (for example around sexuality) and delay help‑seeking for mental illness.
In highly secular societies, belonging to a religious minority may correlate with poorer health, possibly via discrimination, lower social integration or economic disadvantage. A critical economic analysis even reports a negative relationship between religious background and some health indicators once socioeconomic factors are carefully controlled, challenging simple “religion is good for you” narratives.
Methodological problems
Much of the evidence relies on observational studies, making it difficult to be sure about causality: healthier or more socially integrated people may be more likely to be religiously active. Measures of religiosity and spirituality are heterogeneous, ranging from attendance to private practices to diffuse “spiritual well‑being”, which complicates comparisons and may inflate positive findings. In other words, the effects of religiosity on health are less that certain or clear.
Innovations in both the surgical and medical management of breast cancer over the past few decades have led to reductions in treatment-related morbidity and increases in overall survival. Despite these advancements in surgery, chemotherapy, radiation, endocrine therapy, and immunotherapy, a subset of patients continues to choose so-called alternative medicine (SCAM). The objective of this study was to describe the association of SCAM with survival in patients with breast cancer.
This cohort study analyzed data from the National Cancer Database on female patients diagnosed with breast cancer from 2011 through 2021. Survival time was compared among patients who received conventional treatment, conventional treatment plus SCAM, and SCAM only. Data were analyzed from May 2025 to December 2025.
The primary outcome was 5-year survival. Unadjusted 5-year survival was assessed by Kaplan-Meier analysis, and adjusted survival was assessed with a Cox proportional hazards model controlled for age, race and ethnicity, Charlson Comorbidity index, insurance type, facility type, region, year of diagnosis, cancer stage, and income.
Of 2 169 202 female patients with breast cancer identified, 2 157 219 (median [IQR] age, 62 [52-71] years) were included in the sample. A total of 2 106 665 patients (97.6%) received conventional therapy.
- 273 (<0.1%) received SCAM alone,
- 568 (<0.1%) received a combination of SCAM and coventional therapies,
- 49 713 (2.3%) received no treatment.
Compared with patients treated with conventional therapies, those treated with SCAM alone (adjusted hazard ratio [AHR], 3.67; 95% CI, 3.03-4.44; P < .001) or no treatment (AHR, 3.53; 95% CI, 3.48-3.58; P < .001) had the highest risks for mortality. Patients who received a combination of conventional therapies and SCAM were less likely to receive endocrine therapy (eg, 40.7% vs 65.2% in stage II; P < .001) and radiation (59.5% vs 36.6% in stage II; P < .001) compared with patients treated exclusively with conventional therapies. Receipt of a combination of conventional therapies and SCAM was associated with a higher mortality compared with being treated exclusively with conventional therapy (AHR, 1.45; 95% CI, 1.22-1.72; P < .001).
The authors concluded that, in this cohort study of data from female patients with breast cancer included in the NCDB, the use of SCAM instead of conventional therapies was uncommon but was associated with a reduction in survival time. Further study is warranted.
The full text of this study is worth reading. It shows clearly that patients who use SCAM – even as an additional therapy – tend to skip some live-saving treatments. Why? Possibly because SCAM therapists persuade them that this is a good idea. I have personally seen this happening several times. It means that the SCAM might well be harmless, but the SCAM therapist is not!
The list of investigations showing that SCAM is a risk factor for cancer patients undergoing oncological treatments is growing. The message for patients is important and clear: stay away from SCAM while receiving curative treatment. Later on, during the supportive or palliative phase of care, some forms of SCAM might be helpful for improving cancer patients’ quality of life. For people with a keen interest in this area, I recommend reading my book which attempts to define which forms of SCAM might be beneficial for cancer patients at what stage of the recovery.
The suppression of scientific data within US federal agencies represents a fundamental tension between independent public health expertise and political ideology. This conflict seems to have now reached a boiling point at the ‘Centers for Disease Control and Prevention’ (CDC), where the Trump administration’s political leadership has indefinitely delayed the publication of an important report demonstrating the continued benefits of the COVID-19 vaccine. This action marks a pivotal shift in how the US manages public health information, signalling an era where data is scrutinized not just for its accuracy, but for its alignment with a specific political narrative.
The controversy centres on a study conducted by career scientists within the CDC’s ‘National Center for Immunization and Respiratory Diseases’. It analyzed data from the winter of 2025 and showed that COVID-19 vaccinations reduced the risk of hospitalization by 55% and emergency room visits by 50% among healthy adults. These figures provide a compelling argument for the vaccine’s role in mitigating the burden on the US healthcare system. However, despite being scheduled for release in the agency’s Morbidity and Mortality Weekly Report (MMWR) in mid-March, the study remains unpublished.
The primary figure behind this delay is the Acting CDC Director, Dr. Jay Bhattacharya. Appointed by the Trump administration and a vocal advocate for the “Great Barrington Declaration,” Bhattacharya has challenged the report’s methodology, specifically the “test-negative design”. This is an observational study design often used to estimate vaccine effectiveness. It compares people who seek care and are test-positive for the target infection with similar people who seek care but are test-negative. The key idea is simple:
- Recruit people with similar symptoms who come for testing.
- Split them into cases, who test positive, and controls, who test negative.
- Compare the odds of prior vaccination or another exposure between the two groups.
If vaccinated people are less common among the test-positive group than among the test-negative group, that suggests the vaccine is effective. This design is efficient because both cases and controls come from the same care-seeking population which reduces confounding. It is also practical during outbreaks, since cases and controls can be identified quickly from testing records.
While Bhattacharya frames his criticism as a commitment to rigorous quality control, the scientific community begs to differ and stress that the test-negative design has been the gold standard for assessing vaccine effectiveness for over twenty years. Indeed, a flu vaccine study using the exact same methodology was approved for publication by the same leadership just days prior, suggesting a double standard applied specifically to COVID-19 data.
This scandalous incident does not exist in a vacuum; it is a manifestation of a broader overhaul of US public health spearheaded by Health Secretary Robert F. Kennedy Jr. Under this leadership, the administration has sought to deprioritize standard immunization schedules and has integrated vaccine skeptics into the Advisory Committee on Immunization Practices (ACIP). By suppressing data that proves vaccine efficacy, the administration creates a vacuum of information that can be filled by more skeptical, politically convenient narratives.
The consequences of all this are profound. When political appointees act as gatekeepers for scientific data, it erodes the public’s trust in the CDC as a neutral, evidence-based institution. High-profile resignations, such as that of Dr. Fiona Havers, suggest a demoralized workforce of career scientists who feel their objective research is being censored. Furthermore, by withholding data that quantifies the protection offered by vaccines, the government limits the ability of healthcare providers and citizens to make informed decisions about their own health risks.
In conclusion, the suppression of the 2026 CDC vaccine report is a watershed moment for scientific integrity in government. It illustrates the danger of a system where data is viewed through a lens of political utility rather than public safety. As the administration continues to reshape federal health policy, the ongoing struggle between career researchers and political leadership will likely define the future of public health transparency in the US. The losers, no doubt, will be the people – primarily in the US but likely also globally.
Sufficient evidence concerning the impact of traditional Chinese medicine (TCM) on clinical outcomes for breast cancer patients in Taiwan is not available. This study sought to examine the association between TCM integration and post-operative outcomes among women undergoing mastectomies.
Utilizing a large insurance database, the Taiwanese researchers identified a cohort of adult women who underwent breast cancer surgery during the 2010–2019 period. They compared sociodemographic profiles and comorbidities between TCM users and non-users. Multiple logistic regression models were employed to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for both mortality and postoperative complications.
Among 91,298 eligible patients, the one-year pre-operative prevalence of TCM utilization was 40%. Compared to the control group, TCM users demonstrated:
- a significantly lower likelihood of postoperative stroke (OR 0.76, 95% CI 0.62–0.93),
- and a reduced requirement for intensive care (OR 0.74, 95% CI 0.59–0.91).
Moreover, the cumulative exposure of more than 4 TCM consultations within the year preceding surgery was linked to a decreased risk of stroke (OR 0.76, 95% CI 0.61–0.95).
The authors concluded that “our findings indicate that integrating TCM during the year preceding breast cancer surgery is correlated with lower risks of postoperative stroke and a reduced requirement for intensive care. Nevertheless, these observed benefits warrant further verification through prospective and large-scale clinical investigations. Based on these results, we suggest that both Western medical practitioners and public health administrators should be mindful of TCM’s role in the comprehensive care of patients with breast cancer.”
In the paper itelf, the authors “hypothesize that pre-operative TCM integration contributes to the observed reduction in stroke risk and intensive care requirements following mastectomy. These prior insights provide a plausible biological foundation for the favorable outcomes observed in our study”. In other words, they believe that the associations is causal.
I beg to differ!
Much research has demonstrated that people who use so-called alternative medicine (SCAM) in addition to conventional therapies differ from those who don’t. In general, they tend to be more health concious – if not, they would not go to the trouble of using and paying for SCAM. This difference alone suffices to bring about the observed outcomes – even if TCM has no or perhaps a slightly negative overall health effect.
But let’s be generous!
Let’s assume the authors are correct in assuming that the association is causal and that TCM brought about the observed outcomes.
What does that actually mean?
TCM consists of many different modalities. If we just focus on oral medications and assume that there are 1000 different ones [in fact, the number is about 6 times higher], which one do we take to experience the observed outcome? Perhaps all of them?
What I am trying to point out that such research is meaningless; it has zero practical consequences, even if its results were real – which they probably are not.
In the end, it boils down to one main thing: the promotion of unproven (and occasionally dangerous) TCM.
Although currently the COVID-19 pandemic is no longer a public health challenge, the unprecedented utilization and integration of Ayush therapeutics and principles for the COVID-19 response in India represent a critical health systems and policy experiment which needs a systematic evaluation.
A systematic review and meta-analysis was conducted, and the data were extracted till 9th July 2024 using three databases: Scopus, PubMed and DOAJ. A total of seven articles were included for the review, following the PICOS criteria of inclusion and exclusion. Of the 667 articles, seven articles were finally selected, and these articles underwent quality assessment using the AXIS assessment tool. The pooled proportion of the Indian population that utilized the Ayush systems was estimated at a 95% confidence interval, using a random effects model assuming potential heterogeneity. The pooled estimate, publication bias, heterogeneity and sensitivity analysis were graphically represented using a forest, funnel, Galbraith plots and leave-one-out meta-analysis. Additionally, the effects of the small studies were assessed using Egger’s and Begg’s tests. The total sample across the included studies was 789,735. Of the seven articles, six focused on the general population, and five focused on the utilization of the Ayurveda system of medicine. The pooled proportion of the Indian population that utilized the Ayush systems for COVID-19 was 40% (95% CI: 25% − 57%). Based on the policy relevance, risk of exposure, access to guidelines and pattern of utilization two subgroup analyses were carried out. Utilization of multiple systems of Ayush (48%) and utilization among the general population (46%) showed the highest proportion compared to Ayurveda and healthcare workers, respectively. The high heterogeneity (I2 = 99.98%) suggests that the pooled estimate should be interpreted with caution, and the sensitivity analysis found one study had a modest upward influence on the overall estimate.
The authors concluded that this systematic review found a 40% pooled estimate of utilization of Ayush systems from the included studies, suggesting the utilization of these systems to manage mild and asymptomatic conditions and for preventive purposes.
This review reports a 40% pooled utilization rate of Ayush systems for COVID-19 in India, based on just seven studies with a massive sample but extreme heterogeneity (I²=99.98%). Such high heterogeneity undermines the reliability of the pooled estimate, as noted in the study’s own caution and sensitivity analysis showing one study’s outsized influence.
Only seven articles met PICOS criteria from 667 screened, mostly surveys on self-reported use among general populations, without assessing clinical efficacy or outcomes. Quality via AXIS tool is mentioned, but broader Ayush COVID evidence reveals high risk of bias in many trials due to poor randomization, blinding, and variability in interventions. No causal link is drawn between Ayush use and health impacts; the paper merely quantifies popularity amid government promotion.
India faced ~2.4-4.7 million excess deaths in 2020-2021, 7-10x official COVID figures, driven by Delta wave surges, oxygen shortages, and healthcare collapse. Widespread Ayush integration for prevention and mild cases – endorsed by Ministry of Ayush! – did not correlate with better results; high utilization (40-48% in subgroups) coincided with catastrophic mortality levels. Sound evidence for Ayush benefits does not exist. One might therefore speculate that the promotion of Ayush may have diverted resources from proven measures like vaccination and antivirals. In other words, it seems likely that it cost many lives.
This prospective cohort study investigated associations of coffee and tea intake with dementia risk and cognitive function. It included female participants from the Nurses’ Health Study (NHS; n = 86 606 with data from 1980-2023) and male participants from the Health Professionals Follow-up Study (HPFS; n = 45 215 with data from 1986-2023) who did not have cancer, Parkinson disease, or dementia at study entry (baseline) in the US.
The primary exposures were intakes of caffeinated coffee, decaffeinated coffee, and tea. Dietary intake was collected every 2 to 4 years using validated food frequency questionnaires. The primary outcome was dementia, which was identified via death records and physician diagnoses. The secondary outcomes included subjective cognitive decline assessed by a questionnaire-based score (range, 0-7; higher scores indicate greater perceived decline; cases defined as those with a score ≥3) and objective cognitive function assessed only in the NHS cohort using telephone-based neuropsychological tests such as the Telephone Interview for Cognitive Status (TICS) score (range, 0-41) and a measure of global cognition (a standardized mean z score for all 6 administered cognitive tests).
Among 131 821 participants (mean age at baseline, 46.2 [SD, 7.2] years in the NHS cohort and 53.8 [SD, 9.7] years in the HPFS cohort; 65.7% were female) during up to 43 years of follow-up (median, 36.8 years; IQR, 28-42 years), there were 11 033 cases of incident dementia. After adjusting for potential confounders and pooling results across cohorts, higher caffeinated coffee intake was significantly associated with lower dementia risk (141 vs 330 cases per 100 000 person-years comparing the fourth [highest] quartile of consumption with the first [lowest] quartile; hazard ratio, 0.82 [95% CI, 0.76 to 0.89]) and lower prevalence of subjective cognitive decline (7.8% vs 9.5%, respectively; prevalence ratio, 0.85 [95% CI, 0.78 to 0.93]). In the NHS cohort, higher caffeinated coffee intake was also associated with better objective cognitive performance. Compared with participants in the lowest quartile, those in the highest quartile had a higher mean TICS score (mean difference, 0.11 [95% CI, 0.01 to 0.21]) and a higher mean global cognition score (mean difference, 0.02 [95% CI, −0.01 to 0.04]); however, the association with global cognition was not statistically significant (P = .06). Higher intake of tea showed similar associations with these cognitive outcomes, whereas decaffeinated coffee intake was not associated with lower dementia risk or better cognitive performance. A dose-response analysis showed nonlinear inverse associations of caffeinated coffee and tea intake levels with dementia risk and subjective cognitive decline. The most pronounced associated differences were observed with intake of approximately 2 to 3 cups per day of caffeinated coffee or 1 to 2 cups per day of tea.
The authors concluded that “greater consumption of caffeinated coffee and tea was associated with lower risk of dementia and modestly better cognitive function, with the most pronounced association at moderate intake levels”.
Changes in the vaccine advisory process in the United States have disrupted immunization guidance, which reinforces the need for independent evidence review to inform decisions regarding immunization for respiratory viruses during the 2025-2026 season.
The researchers conducted a systematic review of U.S.-licensed immunizations against coronavirus disease 2019 (Covid-19), respiratory syncytial virus (RSV), and influenza. They searched databases on PubMed/MEDLINE, Embase, and Web of Science for updates of the most recent review by the Advisory Committee on Immunization Practices (ACIP) Evidence-to-Recommendations for each disease, which was performed during the 2023-2024 period. Outcomes included vaccine efficacy and effectiveness against hospitalization, other clinical end points, and safety.
Of 17,263 identified references, 511 studies met the inclusion criteria. Covid-19 mRNA vaccines against the XBB.1.5 subvariant had pooled vaccine effectiveness against hospitalization of 46% (95% confidence interval [CI], 34 to 55; from cohort studies) and 50% (95% CI, 43 to 57; from case-control studies) among adults and 37% (95% CI, 29 to 44) among immunocompromised adults. In a case-control study, vaccines against the KP.2 subvariant showed an effectiveness of 68% (95% CI, 42 to 82). Maternal RSV vaccination (for infant protection), nirsevimab for infants, and RSV vaccines in adults who were 60 years of age or older showed vaccine effectiveness of 68% or more against hospitalization. Influenza vaccination had a pooled vaccine effectiveness of 48% (95% CI, 39 to 55) in adults between the ages of 18 and 64 years and 67% (95% CI, 58 to 75) in children against hospitalization. Safety profiles were consistent with previous evaluations. The diagnosis of myocarditis associated with Covid-19 vaccines occurred at rates of 1.3 to 3.1 per 100,000 doses in male adolescents, with lower risk associated with longer dosing intervals. The RSVPreF vaccine was associated with 18.2 excess cases of Guillain-Barré syndrome per million doses in older adults; a significant association with preterm birth was not observed when the vaccine was administered at 32 to 36 weeks’ gestation.
The authors concluded that the evidence supports the safety and effectiveness of immunizations against Covid-19, RSV, and influenza during the 2025-2026 season.
On this blog, we have a surprising amount of commentators who seem unconvinced about the benefits of vaccinations, particularly the COVID vaccinations. Therefore, I thought that this recent article might help these confused people to better understand the current evidence.
In contrast to the self-appointed ‘experts’ claiming that vaccinations do more harm than good, the authors of this excellent paper come from the most reputable institutions in the US:
- 1Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA.
- 2Department of Medicine, Division of Infectious Diseases, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
- 3Department of Pediatrics, Mass General Brigham for Children and Harvard Medical School, Boston.
- 4Department of Health Law, Policy, and Management, Boston University School of Public Health, Boston.
- 5Department of Medicine (Infectious Diseases), University of Pennsylvania Perelman School of Medicine, Philadelphia.
- 6Center for Infectious Disease Research and Policy, University of Minnesota, Minneapolis.
- 7Center for Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, WI.
- 8Harvard Medical School, Boston.
- 9Massachusetts General Hospital, Boston.
- 10Department of Epidemiology, Biostatistics, and Occupational Health, School of Population and Global Health, McGill University, Montreal.
- 11Division of Infectious Diseases, Brown University Health and Warren Alpert Medical School of Brown University, Providence, RI.
- 12Division of General Internal Medicine and Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston.
- 13Division of Infectious Diseases, Massachusetts General Hospital, Boston.
Will this new paper convince many anti-vaxers? I sure hope so but somehow I also have my doubts.
- (1) SMT,
- (2) ambulatory ibuprofen prescription,
using propensity matching for OUD risk factors. The primary outcome was the risk ratio (RR) of OUD. The RR for long-term opioid use, and opioid prescription RR and mean count were also explored. Primary analyses conducted in TriNetX and R used logistic regression for matching, standardized mean difference to assess between-cohort balance (threshold of ≤ 0.1), and contingency tables for RRs, using a significance threshold of p < 0.05.
Shingles or herpes zoster (HZ) is a neurotropic virus that causes a painful and hard to treat illness. Evidence is accumulating that HZ vaccinations might lower the risk of dementia. This effect is surprising but well-documented; here are 3 recent meta-analyses:
An international team of scientists aimed to evaluate the association of HZ infection, protective effects of antiviral treatment or vaccination on dementia. Systematic searches of PubMed, MEDLINE, EMBASE, Scopus, Web of Science, CINAHL, and Cochrane CENTRAL was performed from January 1, 1996, to October 31, 2024. Observational studies evaluating HZ infection, antivirals, or vaccination and dementia risk were selected. Risk of bias was examined with the Newcastle-Ottawa scale. A random-effects meta-analysis was performed, with the rate ratio (RR) and corresponding 95% confidence intervals (CIs) being pooled for dementia. Presence of heterogeneity was assessed with I2, and differences by study-level characteristics were estimated using subgroup meta-analysis and meta-regression.
Eighteen studies (N = 9.4 million) were included. Infection was associated with elevated risk of dementia (RR 1.14; 95% CI: 1.04, 1.25, I2 = 98%); this remained significant in the sensitivity analysis when the two case-control studies were removed (RR 1.17; 95% CI: 1.06, 1.30, I2 = 98%). Subgroup analysis based on sex, age, study population, bias scores, type of dementia or HZO did not show statistically significant differences in risk. Treatment with antivirals showed a small effect (RR 0.84; 95% CI: 0.71, 0.99, I2 = 73%), but prophylaxis with HZ vaccination was associated with a significantly lower risk (RR 0.68; 95% CI: 0.56, 0.83, I2 = 99%).
The authors concluded that there is a slightly raised dementia risk after HZ infection and reduced risks after antiviral treatment and prevention with vaccination. However, results should be interpreted with caution due to significant heterogeneity in pooled analyses.
Previous studies have reported a decreased risk of dementia with herpes zoster vaccination. Given this background, this systematic review and meta-analysis aimed to investigate the association between herpes zoster vaccination and the risk of dementia. An Indian/American team searched five databases until November 2023 for case-control, cross-sectional, or cohort studies investigating the association of herpes zoster vaccination and dementia. Odds ratios and 95% confidence intervals (95% CIs) were pooled in the meta-analysis. Meta-regression, subgroup, and sensitivity analysis were also conducted. The researchers evaluated a total of five studies (one cross-sectional, one case-control, and four cohort studies) that included a total number of 103,615 patients who were vaccinated with herpes zoster vaccine. All the studies were of high quality, ranging from 7 to 9. Due to the high heterogeneity (I2 = 100%, p < .00001) observed in our study, a random effect model was used for the analysis. The pooled odds ratio was 0.84 (95% CI: 0.50, 1.43), p (overall effect) = .53), indicating that herpes zoster vaccination reduces the risk of dementia.
The authors concluded that herpes zoster vaccination is associated with a reduction of the risk of dementia. More epidemiological studies are needed to confirm the association.
Herpes zoster (HZ) infection may increase the risk of dementia, that causes a heavy socioeconomic burden. However, the epidemiological evidence between HZ vaccination and the risk of dementia remains inconclusive. This meta-analysis was conducted to investigate the effect of HZ vaccination on the onset of dementia. The researchers searched PubMed, EMBASE, Web of Science, Science Direct, and Scopus for cohort studies assessing the association between HZ vaccination and dementia risk up to 20th January 2025. Hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled adopting a random-effect model. Four eligible studies were included in the systematic review and five retrospective cohort studies in the meta-analysis. Among 14,493,383 dementia-free participants at baseline, 427,309 dementia cases occurred during 36-95 months of follow-up. All studies were of high quality. Pooled analysis of adjusted HRs indicated that HZ vaccination could reduce dementia risk by 29% (HR = 0.71, 95% CI: 0.66-0.76, I2 = 97.15%). Subgroup analyses revealed heterogeneity linked to definitions of dementia, exposure measurements, vaccination doses, deprivation index, and region. The results were stable in the sensitivity analyses, and no publication bias was found.
The authors concluded that HZ vaccination was notably related to a reduced risk of dementia. More mechanistic studies and epidemiological studies are warranted.
_______________
The effect seems powerful and faily consistent across different studies. But how can this be? Australian neuroscientists have suggested that subclinical zooster virus reactivation might act as a renewable peripheral immune stressor, amplifying microglial priming in aging brains. Shingles vaccination may suppress this viral reservoir, reducing cumulative inflammatory tone.
Whatever the mechanism, the news that zoster vaccination might strongly reduce the dementia risk is hugely encouraging. It could also, I hope, have the effect that the dangerous anti-vaccination attitude currently fuelled by the incompetent US govenment will be getting a little less popular.
PS
Needless to say that these vaccinations also reliably prevent shingles!
So please, do consider getting vaccinated.
