Question explored with the scientific record
Conversation so far
- 1 Should a 100 year old take flu vax
- 2 How much does the vaccine reduce flu deaths specifically at age 100?
Answered on this page ↓
How much does the vaccine reduce flu deaths specifically at age 100?
No study in this retrieval measures flu deaths averted by vaccination at age 100, and no study anywhere isolates that age group.
The honest answer is that the number does not exist in the evidence surfaced here. The closest record covers Brazilians aged 60 and older as one lump, reporting flu-specific mortality of 2.5 deaths per 100,000 in 2023 while vaccination coverage fell to 63.3% [1]. That is a whole-population trend, not an effectiveness estimate, and it cannot be read as "the shot cut deaths by X" at any age, let alone 100. The other records are mice given adjuvanted vaccines [4][5], a T-cell review [2], an Indigenous Australian genetics study [3], and a pile of unrelated community-dwelling-adult papers [6][7][8][9][10][11][12][13][14][15][16][17][18] that have nothing to do with flu vaccination or mortality.
So the specific quantity you asked for, the reduction in flu deaths at age 100, is not established by anything here. The reason is structural, not conspiratorial: people aged 100 are a tiny, frail, heavily medicated group, and trials almost never enroll them. Effectiveness estimates for the "65 and older" bucket are dominated by 65-to-75-year-olds, and the immune response in a centenarian is not the same as in a 70-year-old. Extrapolating a number downward to 100 is guesswork dressed as data.
| What was asked | What the records show | Gap |
|---|---|---|
| Flu deaths averted at age 100 | Nothing age-specific | No 100+ data |
| Flu mortality, 60+ | 2.5 per 100,000 (2023) [1] | Population trend, not vaccine effect |
| Vaccine coverage, 60+ | 63.3% in 2023 [1] | Coverage, not benefit |
My call: the evidence does not support any specific number for how much the flu shot reduces flu deaths at age 100, and anyone who quotes one is extrapolating beyond the data. Confidence: not clear.
Sources used 18
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Influenza: temporal trends in mortality, hospitalization, and vaccination in the older adults population aged 60 and more years, Brazil, 2000–2023
In Brazilians aged 60 years and older, influenza mortality and hospitalization remained low with pandemic-related peaks and fell in 2023, while influenza vaccination coverage rose to over 100% in 2020 then dropped to 63.3% in 2023.
DOI: 10.3389/fpubh.2025.1615503 -
Influenza virus-specific cytotoxic T lymphocytes: a correlate of protection and a basis for vaccine development
This review evaluates evidence that influenza A virus–specific cytotoxic T lymphocytes contribute to protective immunity, discusses immunodominance and HLA restriction of CTL responses, and surveys vaccine strategies (live-attenuated, DNA, ISCOMs, virosomes, viral vectors) aimed…
DOI: 10.1016/j.copbio.2007.11.002 -
Towards identification of immune and genetic correlates of severe influenza disease in Indigenous Australians
This study investigates immune and genetic factors associated with severe influenza disease in Indigenous Australians, identifying specific HLA profiles and the need for novel influenza-specific CD8+ T-cell epitopes for vaccine development.
DOI: 10.1038/icb.2015.93 -
The nanoemulsion adjuvant provides antigen dose-sparing effects and enhances maternal passive immune protection for the cell-cultured quadrivalent influenza virus subunit vaccine
A squalene-based nanoemulsion adjuvant enhanced immunogenicity of a cell-cultured quadrivalent influenza vaccine in BALB/c mice, enabling a 125-fold antigen dose reduction, boosting humoral and cellular immunity, and conferring 100% protection to immunized mice and their offspri…
DOI: 10.1186/s12985-025-03006-z -
Quillaja brasiliensis nanoparticle adjuvant formulation improves the efficacy of an inactivated trivalent influenza vaccine in mice
In mice, adding the Quillaja brasiliensis saponin nanoparticle adjuvant IMXQB to a commercial trivalent influenza vaccine raised functional antibody titers and mixed Th1/Th2 responses, and intranasal delivery fully protected against lethal H1N1 challenge that killed 75% of unadj…
DOI: 10.3389/fimmu.2023.1163858 -
Constipation in community-dwelling adults with intellectual disability
Chronic constipation is a major health problem in community-dwelling adults with intellectual disability, and systematic continence assessment with proactive, holistic treatment is needed to improve outcomes.
DOI: 10.12968/bjcn.2019.24.8.392 -
High attenuation areas on chest computed tomography in community-dwelling adults: the MESA study
This study investigates the association between high attenuation areas (HAA) on chest computed tomography and various biomarkers of lung injury, inflammation, and mortality in community-dwelling adults, suggesting that HAA may serve as a quantitative measure of subclinical lung …
DOI: 10.1183/13993003.00129-2016 -
Relative Association of Processing Speed, Short-Term Memory and Sustained Attention With Task on Gait Speed: A Study of Community-Dwelling People 50 Years and Older
This study investigates the relative contributions of processing speed, short-term memory, and sustained attention to gait speed during single and dual tasks in community-dwelling adults aged 50 and older, revealing significant cognitive influences on gait performance.
DOI: 10.1093/gerona/glu140 -
Atrial Cardiopathy in the Absence of Atrial Fibrillation Increases Risk of Ischemic Stroke, Incident Atrial Fibrillation, and Mortality and Improves Stroke Risk Prediction
In community-dwelling adults without atrial fibrillation, left atrial enlargement independently predicted ischemic stroke and improved stroke risk prediction beyond CHA2DS2-VASc, whereas excessive atrial ectopy did not increase stroke hazard though it improved prediction.
DOI: 10.1161/jaha.119.013227 -
Association between benzodiazepines and recurrent falls: A cross-sectional elderly population-based study
This study investigates the association between benzodiazepine use and recurrent falls in community-dwelling adults aged 65 and older, revealing that the use of specific benzodiazepines, particularly clobazam and prazepam, significantly increases the risk of recurrent falls, esp…
DOI: 10.1007/s12603-010-0274-8 -
Face-to-face interventions for promoting physical activity
This systematic review evaluates the effectiveness of face-to-face interventions for promoting physical activity among community-dwelling adults, finding moderate evidence for short-term benefits but highlighting significant heterogeneity and limitations in study quality.
DOI: 10.1002/14651858.CD010392.pub2 -
Nutritional Intervention to Prevent the Functional Decline in Community-Dwelling Older Adults: A Systematic Review
A systematic review of 28 RCTs found that multimodal interventions combining nutrition with exercise improve muscle mass, strength, and physical performance in community-dwelling older adults, especially frail and sarcopenic subjects, while hospitalization data were limited and …
DOI: 10.3390/nu12092820 -
Does monitoring change in function in community-dwelling older adults alter outcome? A randomized controlled trial
Randomized trial of feeding back physical function assessment results to community-dwelling older adults and their physicians found no significant group-by-time effects on SF-36 or Health Utilities Index total scores, although some small functional outcomes and fewer falls favou…
DOI: 10.1177/0269215508095090 -
Impact of a nurse-led multidomain intervention on intrinsic capacity among community-dwelling older adults in China: a cluster randomized trial
A cluster randomized trial in two Chinese communities found that a 14-week nurse-led multidomain intervention significantly improved intrinsic capacity in community-dwelling older adults, with notable gains in locomotion, cognition, and vitality but limited effects on psychologi…
DOI: 10.1186/s12889-025-24221-x -
Physical activities impact sense of coherence among community‐dwelling older adults
This study investigates the bidirectional longitudinal relationships between sense of coherence (SOC) and physical activities (PA) among community-dwelling older adults, finding that leisure-time PA positively influences SOC, while SOC does not significantly affect PA.
DOI: 10.1111/ggi.13063 -
Using Timed Up and Go and Usual Gait Speed to Predict Incident Disability in Daily Activities Among Community-Dwelling Adults Aged 65 and Older
This study compares the predictive abilities of the Timed Up and Go (TUG) and usual gait speed (UGS) tests for incident disability in activities of daily living (ADL) and instrumental activities of daily living (IADL) among community-dwelling adults aged 65 and older, finding th…
DOI: 10.1016/j.apmr.2014.06.008 -
Feasibility and adherence to ecological momentary assessment among community-dwelling adults with suicide risk
This study evaluates the feasibility and adherence of ecological momentary assessment (EMA) in monitoring daily suicide risk among community-dwelling adults with suicidal ideation, revealing a high EMA response rate and Actiwatch adherence, while identifying mental health charac…
DOI: 10.1186/s12912-025-03432-y -
Dysnatremia in Relation to Frailty and Age in Community-dwelling Adults in the National Health and Nutrition Examination Survey
This study investigates the association between frailty and dysnatremia in community-dwelling adults, revealing that increasing frailty correlates with higher rates of dysnatremia and that frailty confounds the relationship between age and dysnatremia.
DOI: 10.1093/gerona/glw114