Vaccines: Health & Economic Benefits | Johns Hopkins

What if a vaccine could reduce your chances of heart attack, stroke, or dementia, and even save you money?

It turns out: those vaccines already exist. Researchers are learning that vaccines against flu, shingles, RSV, measles, and more have benefits beyond preventing the specific diseases they target. Vaccines provide economic benefits for individuals and communities, improve children’s development and education, help prevent cardiovascular events and cognitive decline, and may even train the immune system to defend against new diseases.

Flu, RSV, and pneumococcal vaccines are linked to reduced risk of cardiovascular events in older adults

Every year, tens of millions of people in the U.S. get sick with infectious respiratory illnesses, including flu, RSV, and pneumococcal disease.

Adults over 65 and people with chronic conditions are particularly susceptible to severe complications from these illnesses. This includes the nearly half American adults live with some type of cardiovascular disease, who are more likely to experience severe illness that may result in hospitalization or death.

Whether mild or severe, these illnesses can cause inflammation, explains Kawsar TalaatMD, an associate professor in International Health. That inflammation increases a person’s likelihood of experiencing a major adverse cardiovascular event—like a heart attack (myocardial infarction), stroke, or episode of congestive heart failure—while they’re sick or in the weeks and even months following.

In addition, “when you get sick, there’s more strain on your heart,” Talaat says. “Making [your heart] work harder increases the oxygen demand, which could lead to ischemia [decreased blood flow to parts of the body] and lead to a heart attack.” In fact, one study found that nearly 1 in 4 adults over 50 hospitalized with RSV experienced an acute cardiac event during their hospitalization—including nearly 1 in 10 who did not have an underlying cardiovascular disease.

“If you prevent the infection from happening, then the downstream effects—the cardiac events, the strokes—don’t happen,” Talaat says.

Other studies have shown an association between flu vaccination and reduction in all-cause mortalitysays Anna DurbinMD, a professor in International Health. These benefits have been shown across age groups, but particularly in adults over 65.

Multiple benefits linked to shingles vaccination

When someone gets chickenpox, the varicella-zoster virus stays in their body for life. It can then be reactivated—due to age, stress, or a suppressed immune system—causing shingles, or herpes zoster.

A mounting body of research shows that shingles vaccination—a two-dose regimen for adults 50+ and some immunocompromised younger adults—doesn’t just protect against reactivation of the virus and potential complications from it. It also reduces a person’s risk of heart disease, stroke, dementia, and death.

The same indirect mechanism at play with flu and other vaccines is likely at play with the shingles vaccine, says Durbin: By preventing the disease itself, which is highly inflammatory, you prevent the subsequent increased risk for adverse cardiovascular events.

Multiple studies indicate an association between shingles reactivation and incidence of dementia. Research is ongoing to determine whether the reduced risk of dementia is a result of preventing the virus from recurring, a mechanism in the vaccine itself, or a combination of the two. An April 2025 study suggests that the AS01 adjuvant—an ingredient added to boost the immune response of the vaccine—could play a role in protection against dementia. That study showed associations between both the shingles vaccine Shingrix and the RSV vaccine Arexvy, both of which are AS01 vaccines, and reduced incidence of dementia.

MMR vaccination helps fight more than measles, mumps, and rubella

Measles causes not only uncomfortable symptoms like high fever and rash, and potential severe complications, including pneumonia, encephalitis, brain damage, and death. Measles infection also causes immune amnesia, explains Talaat. “Your immune memory to previous vaccinations, previous infections, [is] gone, so you’re susceptible to them” as if you’ve never encountered them. “You’re more at risk, for example, of dying from diarrhea or pneumonia after being sick with measles,” she says. “By preventing measles cases, you not only prevent the cases and mortality directly due to measles, but all-cause mortality because of the effects the measles virus has on the immune system.”

Furthermore, initial research into the additional protective benefits of the MMR vaccine suggests it may induce what’s called “trained immunity,” Durbin says—meaning that “it protects against more than just measles, mumps, and rubella.”

“It trains your immune system to be geared up for new pathogens,” Durbin explains. “So, even though you haven’t seen that pathogen before, your immune system acts like it’s seen it before, and you clear the infection more readily.”

Vaccination helps kids stay on track in school

When kids are sick, they risk missing out on essential classroom time. Vaccine-preventable illnesses “often result in extended absences from school, jeopardizing students’ academic progress and increasing the likelihood of dropping out,” according to the National Education Association.

Families with higher income may have the resources to help kids catch up and avoid any lasting effects, says Talaat. “But for kids from lower income families who are just barely making it in school, losing three weeks’ worth of instruction may put them so far behind that they can’t catch up.”

Vaccination offers financial benefits to individuals and communities

For the more than half of all workers in the U.S. who are paid hourly, having to stay home due to illness or to provide care for a sick child often means losing that day’s wages. “If a parent can’t go to work, that hurts the economic potential of the entire family,” Talaat says. She points to recent news as an example: “In South Carolina, 150 unvaccinated kids who have been exposed to measles have now been told to quarantine for three weeks. … Somebody has to stay home with those kids. If you don’t have the luxury of teleworking at home, you might not be getting a paycheck for those three weeks.”

Outbreaks cost more than the medical care or hospitalization required for individual cases; it also accounts for the resources needed to contain the outbreak through contact tracing and diagnostic testing, and the cost of lost wages and productivity. In 2018–2019, a measles outbreak in Clark County, Washington, carried an estimated societal cost of $3.4 million—about $47,000 per confirmed case—according to economists at the International Vaccine Access Center.

Ultimately, it costs less to prevent an illness through vaccination than to treat it. Calculations from the CDC show that “every $1 spent on childhood immunizations results in a savings of approximately $11.” Another analysis found that in the 25 years after the varicella (chickenpox) vaccine was introduced, it prevented more than 91 million varicella cases, for a net societal savings of $23.4 billion.