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Editor’s note: Dr. Amy Compton-Phillips is the chief medical officer of CVS Health and a board-certified internist.
A patient sat across from me not long ago and told me she wasn’t sure she could trust vaccines anymore.
She wasn’t angry. She wasn’t dismissive of science. She was trying to make a careful decision — weighing what she had heard, what she had been told and what she had seen change over time. She told me she wanted to do the right thing for herself and her family but wasn’t sure what that was anymore.
That conversation has stayed with me. Lots of things surprised me about living through COVID, but probably the one with the longest tail is how my friends, family and patients think about vaccines.
The rise in vaccine skepticism across the globe since 2019 is not a fringe phenomenon. Nor, in most cases, is it irrational. People are not, by and large, reading bad science. They’re trying to reconcile conflicting information and changing guidance and concluding that caution is the responsible posture.
That instinct deserves respect and a serious response. And that serious response is the science and the evidence supporting vaccination have not stood still.
While much of the public conversation has focused on COVID vaccines, the broader science of immunization has been producing some of its most compelling findings in decades, and many have nothing to do with the disease the vaccines were designed to prevent.
Consider shingles. In April 2025, a team from Stanford led an unusually clean, natural experiment from Wales, where eligibility for the shingles vaccine was determined by a sharp birthdate cutoff. Older adults who received it were 20% less likely to be diagnosed with dementia over the next seven years than their near-identical peers who had missed the cutoff by weeks.
An Oxford study of more than 200,000 Americans found that receiving the recombinant vaccine is associated with a 17% increase in time spent free of a dementia diagnosis. A separate analysis presented at IDWeek 2025, drawing on records from 174,000 patients, found that vaccinated adults had a 50% lower risk of vascular dementia, a 25% lower risk of heart attack or stroke, and a 21% lower risk of death from any cause during follow-up.
These are not boutique findings. They are large, replicated and increasingly mechanistic: Investigators now suspect the vaccine’s adjuvant itself trains the immune system in ways that ripple far beyond the shingles (and chicken pox) causing varicella-zoster virus. For decades, immunologists have observed a phenomenon they now call trained immunity, in which certain vaccines durably reprogram innate immune cells to respond more vigorously to unrelated pathogens. The immune system, as it turns out, learns more broadly than we taught it to.
We see this extend to cardiovascular benefits. Six randomized trials, pooled in a 2023 meta-analysis, found that influenza vaccination in patients with established heart disease reduced major cardiovascular events by roughly 26% and cardiovascular death by a third. The American Heart Association recommends several vaccines, including flu, pneumovax, shingles and COVID-19, as part of cardiovascular care due to their ability to lower risk of heart disease.
None of this resolves the concerns people bring to the exam room. Side effects are real. Myocarditis after mRNA vaccination for COVID, though rare and typically self-limited, is real. The mistakes public health institutions made under pandemic pressure — overstating certainty, shifting recommendations without explaining why, treating dissent as deviance — were real, and came with a cost that we’re still paying. A patient who tells me she does not trust the system is not telling me something false. She’s telling me something I need to understand.
Still, empathy is not the same as agreement. The clinician’s job is to bring the newest evidence to the oldest fear. When thinking about both lifespan and health-span, the biggest concern my friends, family and patients articulate is not influenza or shingles. It’s dementia. It’s the possibility of losing memory, independence and identity — watching that happen in someone they love, or imagining it for themselves.
That is a different conversation than the one we’ve been having. Not whether to trust the institutions of 2021, but to look honestly at the data in 2026 about what vaccines actually do: tune the immune system over a lifetime, with benefits to the heart, the brain and the years we have left with the people we love.
I believe our job in healthcare is to help people live longer, healthier lives. Vaccines can help. In medicine, that’s what progress looks like.