I assume we have fewer vaccine skeptics than the mainstream populace, but this is a good reminder, and maybe a caution to the deniers…
BTW, this isn’t intended a political:
https://www.nytimes.com/2026/01/03/health/vaccines-dementia-heart-elderly.html
Paywall 
Apologies. Here is the Gemini AI summary:
Recent research has confirmed that common vaccines for older adults provide significant “off-target” benefits, particularly in reducing the risk of dementia and Alzheimer’s disease.1
While these vaccines are designed to fight specific infections (like shingles or the flu), they appear to “train” the immune system or reduce chronic inflammation, which are key drivers of cognitive decline.2
Studies published in late 2024 and throughout 2025 have highlighted several vaccines that show a protective effect against dementia:
| Vaccine Type | Estimated Risk Reduction | Key Findings |
|---|---|---|
| Shingles (Recombinant) | 20% – 30% | The modern shingles vaccine (Shingrix) shows a stronger protective effect than the older live vaccine. |
| RSV (Arexvy) | 29% | New data from 2025 suggests this vaccine significantly delays dementia onset within 18 months of receipt. |
| Flu (Influenza) | 17% – 40% | Regular annual flu shots are associated with a cumulative reduction in Alzheimer’s risk. |
| Pneumonia | 25% – 40% | Benefits are particularly strong in individuals who do not carry the APOE-ε4 “Alzheimer’s gene.” |
| Tdap | 30% | Tetanus, diphtheria, and pertussis shots also correlate with lower dementia rates. |
Scientists are exploring three main theories for why these “off-target” benefits occur:
The Adjuvant Effect: A major 2025 study from the University of Oxford suggests that an ingredient called AS01 (found in both the Shingrix and Arexvy vaccines) may be responsible.3 This “adjuvant” is designed to boost the immune response and may inadvertently stimulate immune cells to clear brain plaques. 4
Reducing Neuroinflammation: Severe infections can cause systemic inflammation that crosses into the brain.5 By preventing these infections, vaccines stop a “chain reaction” that leads to brain cell damage.
The “Infection Hypothesis”: Some researchers believe that dormant viruses (like the shingles virus) may slowly damage the nervous system over decades.6 Keeping these viruses suppressed through vaccination prevents this slow-motion damage.
The “Natural Experiment” in Wales: Researchers used a 2013 policy in Wales that rationed shingles vaccines based on birth dates.7 This created a perfect “randomized” group. The results showed that those born just days apart—one eligible for the shot and one not—had a 20% difference in dementia diagnoses years later.
Therapeutic Potential: New evidence suggests vaccines might not just prevent dementia but could also slow its progression in people who have already been diagnosed. 8
Note: While these findings are consistent across millions of health records, they are still “observational.” Clinical trials are currently being planned to prove a direct cause-and-effect relationship.
Thanks for adding this summary, @JamesIgoe. It bolsters my overall (but not comprehensive) favorable view of vaccines as an effective public health benefit.
The text version…
Question
how many lives do vaccines save, in terms of the number reaching adulthood?
Answer
Recent research published in The Lancet and by the World Health Organization (WHO) provides a clear picture of how many lives vaccines save, specifically highlighting their impact on child survival into adulthood.1
Since the launch of the Expanded Programme on Immunization (EPI) in 1974, global immunization efforts have saved an estimated 154 million lives.2
Infant Survival: Of those 154 million lives, 101 million were infants who would have otherwise died before their first birthday. 3
Reaching Adulthood: The study found that immunization is the single greatest contributor to ensuring babies not only survive infancy but continue leading healthy lives into adulthood. 4
Probability of Survival: Today, a child under the age of 10 has a 40% greater chance of living to see their next birthday compared to a hypothetical world without vaccines.5 This increased probability of survival continues throughout the life course.
On a year-to-year basis, vaccines are a massive engine for survival:
Current Rate: Vaccines save between 3.5 million and 5 million lives every year .6
Frequency: This is equivalent to saving 6 lives every minute of every da y.7
The impact is not evenly distributed across all diseases. A few “heavy hitters” account for the majority of the survival gains:
| Vaccine | Estimated Lives Saved (1974–2024) |
|---|---|
| Measles | 94 million (approx. 60% of all lives saved) |
| Hepatitis B | Significant long-term impact on adult cancer/cirrhosis deaths |
| Polio | 20 million people are walking today who would have been paralyzed |
| Tetanus/Pertussis | Millions of neonatal and early childhood deaths averted |
Beyond just “not dying,” vaccines improve the quality of life for those reaching adultho od:8
Full Health Years: For every life saved, an average of 66 years of full health are gai ned.9
Productivity: In the U.S. alone, vaccinations for children born in the last 30 years are estimated to save $2.7 trillion in societal costs by preventing disability and lost wa ges.10
The question I really wanted answered:
Answer:
To understand the scale, you have to look at the “1-in-4” rule that dominated human history for centuries.
For most of the last few centuries in Europe, reaching adulthood was a coin flip for many families.
Child Mortality: Around 25% of children died before their 1st birthday, and roughly 40–50% died before reaching adulthood (age 15).
The “Replacement” Culture: Because death was so common, families typically had 6–8 children just to ensure 2 or 3 survived to continue the family line.
Primary Killers: Smallpox was the “King of Terror,” killing about 1 in 10 of all people born in 18th-century London. Other major killers included Diphtheria (which would suffocate children), Measles, and Whooping Cough.
Smallpox was the first disease to be tackled.2 Before Edward Jenner’s vaccine (1796), smallpox was a universal childhood rite of passage—nearly everyone caught it, and 30% died.
Impact: In Sweden, smallpox deaths dropped by over 90% within decades of introducing the vaccine.
Early Success: This was the first time in history a specific medical intervention (rather than just better food or weather) visibly moved the needle on national death rates.
It is a common historical fact that mortality began to drop before most modern vaccines (like Polio or Measles) were invented.
The Role of Hygiene: Between 1850 and 1920, child mortality in Europe halved primarily due to clean water, better sewers, and improved nutrition.
The Limits of Hygiene: While sanitation stopped “filth diseases” like Cholera and Typhoid, it did not stop airborne diseases like Measles or Polio. In fact, Polio became worse as hygiene improved (because children weren’t exposed to it as infants when they had maternal antibodies).
Vaccines provided the “finishing blow” to childhood mortality, taking it from “low” to “rare.”
| Disease | Pre-Vaccine Era (Europe) | Post-Vaccine Era |
|---|---|---|
| Diphtheria | Leading cause of child death (thousands annually) | Virtually zero cases in most of Europe |
| Polio | Thousands paralyzed annually (Iron Lungs) | Eradicated in the European region (since 2002) |
| Measles | Universal infection; 1–2% mortality | Rare outbreaks; deaths are extreme outliers |
If you were born in London in 1841, your chance of dying before age 5 was about 25%. Today, in the UK or most of Europe, that risk is less than 0.4%.
While the first 50% of that improvement came from pipes and food (sanitation), the last—and hardest—30–40% of the decline is directly attributed to the era of mass immunization that began in the mid-20th century.
There is a blindness that develops when things are so good for so long. It occurs in stock markets and in geopolitics, to name a few. We forget the prior horrors, lose the fear of reoccurrence, or think “It can’t happen here.” Since we no longer experience things like polio, and have such good vaccine precautions for so long, many have forgotten, but also, there is the profit motive. The some people make their money from misinformation, and many of those are in power, or very close to it.
