As part of our Vaccine Engagement Day campaign, we are sharing a series of blogs exploring the impact of vaccines, from major public health successes to future innovations. This post looks at the additional, and often overlooked, benefits of vaccination.
Vaccines protect our bodies against specific diseases by triggering the immune system to produce antibodies to "fight them off". They prevent millions of deaths every year globally and protect against some of the most fatal and severe infectious diseases.
Many vaccine-preventable diseases carry a high risk of death without treatment: rabies is almost always fatal once symptoms appear, while tetanus, Ebola and meningococcal disease all have mortality rates of around 50%. They also protect against diseases which can have detrimental long-term consequences, such as polio, which can lead to permanent paralysis, and human papillomavirus (HPV), the primary cause of cervical cancer.
But, the benefits of vaccines reach far beyond this individual protection. Increasingly, research shows they also support long-term health, such as reducing the risk of heart failure and strokes, public health benefits like protecting vulnerable populations, and societal benefits such as supporting school attendance in children! #CelebrateVaccines
Health benefits beyond infection prevention
Cardiovascular protection
Beyond their targeted protection, vaccines offer a surprising range of wider health benefits. A large analysis combining results from 63 studies found that people who received the flu vaccine had a 26% lower risk of cardiovascular disease compared with those who weren’t vaccinated (including strokes, heart failure, myocardial infarction).
Why? Because when the immune system is exposed to flu, it triggers widespread inflammation that can put extra strain on the heart and blood vessels. By preventing flu infections in the first place, vaccination helps reduce this inflammatory stress, which helps protect heart health.
Dementia and brain health
Vaccination may also play a role in reducing dementia risk. Large population studies have found that people receiving routine vaccinations, such as those that protect against seasonal flu, tetanus, and shingles, are less likely to develop Alzheimer’s disease or related dementias later in life. Researchers think this benefit may come from lowering the frequency of severe infections, which can contribute to chronic inflammation and damage within the brain.
Autoimmune disease prevention
Another emerging area of interest is how vaccines can reduce the risk of autoimmune diseases that are sometimes spurred by infection. Some infections can act as “triggers” for autoimmune diseases, which happen when the immune system mistakenly attacks the body’s own tissues. For example, COVID-19 has been linked with a risk of vasculitis conditions (inflammation of the blood vessels, causing them to swell, weaken, or narrow), influenza and rubella infections are linked with Type 1 diabetes, and herpes simplex virus-1 with autoimmune encephalitis.
One possible mechanism is known as bystander activation, where an infection triggers widespread inflammation that activates immune cells beyond their intended targets. Then there's epitope spreading, in which an immune response initially directed at a virus or bacterium expands to target the body’s own tissues.
Another proposed mechanism is molecular mimicry, in which components of a virus or bacterium resemble the body’s own proteins, leading the immune system to target both the pathogen and healthy tissue. For instance, the Epstein-Barr virus (EBV), the cause of glandular fever, has been linked to autoimmune conditions like multiple sclerosis (MS). In MS, the immune system attacks myelin, the protective sheath around nerve fibres, disrupting nerve signalling. Researchers believe EBV may trigger immune responses that mistakenly target myelin (see image A).
By preventing infections, vaccines could help reduce the risk of these harmful immune responses. This is an exciting and promising focus for current immunological research!
Strengthening the immune system
Beyond these specific examples, vaccination helps maintain a more resilient immune system overall. Each vaccination acts as a safe ‘training session’ for immune cells, strengthening immunological memory. This concept, known as trained immunity, shows that some vaccines, like Bacillus Calmette–Guérin (BCG) (used to prevent tuberculosis) or the measles, mumps, rubella and chickenpox (MMRV) vaccine, can enhance innate immune responses to unrelated infections. This may help explain why fully vaccinated individuals often experience fewer severe infections in general.
In short, every vaccine dose acts as an investment in broader health, not just preventing disease, but reducing inflammation, protecting vital organs, and promoting immune balance that supports long-term wellbeing.
Protecting communities through vaccination
Vaccination is often thought of as a personal choice with personal protection, but its impact reaches far beyond the individual.
When enough people are protected, infections struggle to spread. This creates a layer of protection often referred to as herd immunity, where those who are vaccinated help reduce the chances of infection reaching others. This is particularly important for people with weakened immune systems. For example, someone undergoing chemotherapy may not be able to produce a strong immune response, leaving them more vulnerable to everyday infections.
These collective benefits are also felt by the NHS. By preventing infections before they develop (and preventing diseases discussed above), vaccines help reduce hospital admissions and ease seasonal pressures on already overstretched services. This means more time, space, and resources for treating cancer, managing chronic conditions, and responding to emergencies.
In this way, vaccination is not just about individual protection. It is a shared effort that helps keep healthcare systems running and protects those most at risk.
The social and economic value of vaccination
The impact of vaccination is also felt in everyday life.
When illness is prevented, our important routines are less likely to be disrupted. Healthy children are more likely to have a higher school attendance, keeping up with their cognitive and social development. Adults are better able to remain in and travel for work, maintaining financial stability and supporting their families. Communities, in turn, are less affected by the uncertainty and disruption that outbreaks can bring.
At a wider level, this stability matters. In the UK, around 149 million working days are lost each year due to sickness, with roughly 30% linked to minor illnesses such as colds, flu and other infections. Fewer infections mean fewer sick days, less strain on workplaces, and reduced pressure and costs for healthcare systems. Over time, this supports not only healthier individuals, but whole populations and their productivity, learning, and long-term opportunities, helping to build a stronger and more resilient society.
Taken together, these effects show that vaccination is not only a tool for preventing disease, but a foundation for healthier, more stable societies. And that’s worth celebrating!
By Madeline Crouch, Marketing and Communications Officer