August 4, 2026
The Heart, Head, and Vaccine Connection
By Donna M. Lisi, PharmD, BCPS, BCGP, BCACP, BCPP, BCMTMS, CPAFH, CDP, MPLC, FASCP, FAAPP
Introduction
Immunosenescence, the dysregulation or remodeling of the immune system associated with aging, renders older adults more susceptible to infectious diseases.1,2
One way to compensate for this adverse age-related effect is through immunization. Known benefits of immunization in older adults include health benefits (e.g., primary prevention of infectious disease, decreased risk of hospitalization, preservation of functional independence), societal benefits (e.g., herd immunity and eradiation of infectious diseases, prevention of antimicrobial resistance), and economic benefits (e.g., health care cost savings, preservation of workplace productivity).3 Recent data point to the protective effects of vaccinations on cardiovascular health and cognition.
The Cardioprotective Evidence
The data supporting the cardioprotective effects of vaccines are even more compelling than the data involving their neuroprotective effects. As early as 2006, the American Heart Association (AHA), along with the America College of Cardiology (ACC), issued a science advisory recommending the influenza vaccine for the secondary prevention of cardiovascular disease.4
Recommendations to vaccinate against respiratory illnesses is incorporated into the 2022 AHA/ACC/Heart Failure Society of America (HFSA) heart failure guidelines. According to these guidelines, the influenza vaccine is associated with a significant reduction in all-cause mortality, cardiovascular mortality, and cardiovascular, respiratory, and all-cause hospitalizations. Pneumococcal vaccination has been associated with significant reduction in the incidence of heart failure, all-cause mortality, and cardiovascular mortality.5
Similarly, 2023 guidelines from the AHA/ACC, American College of Clinical Pharmacy, American Society of Preventive Cardiology, National Lipid Association, and Preventive Cardiovascular Nurses Association on chronic coronary disease list immunizations under medical therapy to prevent cardiovascular events and manage symptoms. The guidelines provide two Class 1 recommendations, the strongest level of recommendation in which benefits of vaccinations outweigh risks, including for the annual administration of the influenza vaccine to reduce cardiovascular morbidity, cardiovascular death, and all-cause death, and for the administration of the COVID-19 vaccine to reduce COVID-19-related complications. A lesser strength recommendation (2a) favors the use of the pneumococcal vaccine in patients with chronic coronary disease to reduce cardiovascular mortality and morbidity and all-cause death.6
In 2025, the ACC issued an expert consensus statement on adult immunizations as part of cardiovascular care.7 This statement recommends administration of the annual influenza vaccine to reduce cardiovascular morbidity, cardiovascular and all-cause death, and to protect against the adverse sequelae of acute MI and decompensated heart failure. The paper cited single randomized controlled trials and meta-analyses. One meta-analysis found that the influenza vaccine was associated with a 36% lower relative risk of major cardiovascular events (2.9% vs. 4.7%), and this benefit was statistically significant only in those with acute coronary syndrome.8
The IAMI (Influenza Vaccination After Myocardial Infarction) trial, which was terminated early due to COVID-19, found a 28% reduced risk of the primary endpoint, which was a composite of all-cause death, MI, or stent thrombosis within 12 months post-influenza vaccine compared with placebo.9
The guideline recommends administering the pneumococcal vaccine (PCV) for all adults aged > 50 years who have not previously received a PCV vaccine and for all adults aged 19 to 49 years with a chronic medical risk condition, including chronic heart disease, congestive heart failure, and cardiomyopathies. Several studies have demonstrated a cardioprotective effect of the pneumococcal vaccine. One study found that the PPV vaccine significantly reduced the risk of MI, TIA, and stroke, and decreased mortality by 53%; beneficial effects were even more pronounced when administered concomitantly with the influenza vaccine.10
In another clinical trial comparing vaccinated and unvaccinated patients, those who received both the influenza and pneumococcal vaccines had a 35% lower risk of death, 48% lower risk of acute myocardial infarction, 33% lower risk of ischemic stroke, 41% fewer coronary admissions, and 55% fewer ICU admissions.11
Citing a randomized controlled trial, case control, and observational study data, the statement advocates for administering the COVID-19 vaccine. The statement provides CDC dosing recommendations based on whether a patient is treatment-naive. It cautions about the development of vaccine-related myocarditis, which follows a more benign course than COVID-19-related myocarditis.7 The statement also recommends the administration of the respiratory syncytial virus and herpes zoster vaccines, as persons infected with herpes zoster are at increased risk of stroke or heart attacks during active infection.7 The European Society of Cardiology issued a clinical consensus statement in which it called “vaccination a new form of cardiovascular prevention.”12
Proposed mechanisms for vaccines’ cardioprotective effect include reductions in influenza complications and metabolic demands, and modification of immune and inflammatory components of atherosclerosis, leading to plaque stabilization.13 Influenza vaccines’ pleiotropic and anti-inflammatory properties may not correlate with the humoral response (i.e., antibody titers) but further research is needed to determine the extent of these effects in older adults.14 The extent of the cardioprotective benefit seen with influenza vaccines is on par with that conferred by aspirin, beta-blockers, high-dose statins, angiotensin converting enzyme inhibitors, and dual antiplatelet therapy.13,15
The Neuroprotective Evidence
On the other hand, the literature supporting the use of vaccinations for cognitive preservation is more quasi-experimental, based mostly on observational studies. The World Health Organization (WHO) recently issued its second edition of risk reduction of cognitive decline in dementia. In it, the WHO did not incorporate immunizations as a cognitive protective strategy.16
The most prolific amount of vaccine data that points to a possible dementia protective effect is associated with the herpes zoster vaccine.17-19 However, this literature is complicated, as many studies involve the use of the live herpes zoster vaccine (Zostavax®), which was on the market from 2006 to 2020.20,21 This span of time allowed for long-term follow-up studies. The recombinant herpes zoster vaccine (Shingrix®) has only been commercially available since 2017 in the United States. However, data are emerging showing that the recombinant herpes zoster vaccine is associated with a statistically significant reduction in the risk of dementia, including vascular dementia.22-24
Several meta-analyses have found that the influenza vaccine can reduce the risk of dementia by 29-31%.26,27 A recent meta-analysis and systematic review found that the influenza vaccine’s protective effect was most pronounced in high-risk populations (i.e., chronic kidney disease, chronic obstructive pulmonary disease, chronic heart failure, and periodontitis) as opposed to the overall population. Further, there appears to be a dose-dependent effect with the greatest benefit seen after several years of receiving the vaccine.28
Other vaccines, including rabies, tetanus and diphtheria and pertussis, hepatitis A, hepatitis B, polio, pneumococcal, and BCG have been associated with a decreased risk of dementia.29-33 Just how vaccines may protect against dementia is unclear, as the efficacy of vaccines against different pathogens is not the same, but almost all types of vaccines are associated with a significant reduction in dementia risk.29
One study failed to find a beneficial effect of vaccines on dementia risk. The authors cited flaws in other studies’ methodologies that show benefit, including lack of a lag time between vaccination and the diagnosis of dementia, immortal time bias, and healthy vaccine bias, where vaccine uptake may reflect those engaged in a healthier lifestyle.34
With the aging of society, incident heart disease and dementia is rising. The potential of vaccines to offer both cardioprotective and neuroprotective effects could be a game-changer.
Dr. Lisi is an independent clinical consultant pharmacist with over 40 years of experience in geriatric pharmacy. She was appointed to PALTmed’s Infection Advisory Subcommittee/Infection Prevention & Control Committee from 2024-2027. She co-authored PALTmed's 2025 COVID-19 clinical practice recommendations.
References for this article are available here.