The surprising vaccine side effects that can improve long-term health

I am currently in the process of getting my shingles vaccine. I had shingles in college and I still carry the scars from it, so I really don’t want to risk getting it again. But I also think about the fact that the benefits of the shingles vaccine are not limited to preventing shingles. And that’s not unusual. We are discovering that many vaccines have benefits that go far beyond protection against a single virus or bacteria – facts that are not as widely known as they should be.

Let’s start with shingles. A study of more than a million people last year found that people who received the Zostavax shingles vaccine were 26 percent less likely to die of heart disease or suffer a stroke, heart attack or heart failure for an average of six years after the injection – a massive reduction in risk for such a simple, inexpensive and easy procedure.

Additionally, people who received a new shingles vaccine called Shingrix were 17 less likely to develop dementia over the next six years compared to those who received Zostavax. Since several studies have shown that Zostavax also reduces the risk of dementia, the overall risk reduction with Shingrix is ​​expected to be even greater. Several other vaccines, including those that protect against influenza and tuberculosis, also appear to reduce the risk of dementia.

In the United States and Australia, shingles vaccination is recommended for people over the age of 50 or adults with weakened immune systems. Unless you fall into the latter category in the UK, it is only available through public healthcare for people aged 70 to 79. I don’t want to wait that long, so I’ll have to go private.

Shingles is caused by the varicella-zoster virus, which causes chickenpox when it first infects us during childhood and then lies dormant in nerve cells, causing shingles when it is reactivated. So it’s possible that vaccinating children against chickenpox also has some benefits later in life, although I couldn’t find any studies on this topic.

Flu vaccines also have cardiovascular benefits. For example, an analysis combining data from more than 9,000 people involved in six trials found that people vaccinated against the flu had a 34% lower risk of having a heart attack or stroke in the following year. The benefit was even greater for people with a recent history of heart problems.

New vaccines against RSV, or respiratory syncytial virus, also appear to help prevent heart problems. A study of about 130,000 people over the age of 60 found that those who received some type of RSV vaccine were less likely to be hospitalized for heart or lung problems than those who were not vaccinated.

Then there are mRNA vaccines against covid-19. They are found to strengthen the immune response against tumors in conjunction with immunotherapy, thereby extending people’s lives.

I could keep listing examples, but instead let’s look at why so many vaccines have these broader benefits. We don’t know the precise mechanisms for sure, but it’s not surprising that they are.

Viruses can cause lasting physical damage to the body, and the immune response associated with them can also cause tissue damage. So-called cytokine storms, in which the body overreacts and releases too many immune-stimulating signals, often kill people with infections such as the flu or covid-19, for example, and there is growing evidence that multiple sclerosis is the result of the immune response to the Epstein-Barr virus.

Many viruses also target our immune systems in various ways to help us evade them, thereby weakening our defenses. HIV takes this strategy to the extreme, killing it completely.

There are also viruses that we cannot get rid of once they have infected us, such as the varicella zoster virus. Some, like the human papillomavirus (HPV), even genetically modify our cells by inserting their genome into ours – which is why HPV causes cancer.

The fact is that even viral infections that we tend to think of as harmless, like the flu in young people, can have long-term effects that are not always obviously linked to those infections. Studies into long covid have helped raise awareness about it – as well as the benefits of vaccines in reducing the risk of lingering damage.

There is this idea in some circles that “natural immunity” to a disease is somehow better than vaccination. This is crazy for all the reasons above and more, and measles is a prime example.

Measles vaccines have reduced the number of deaths from the disease from more than 2 million per year before 1980 to fewer than 100,000 in 2024. They have also had the unexpected effect of reducing the number of children dying from other infectious diseases.

For what? Part of the answer is that measles kills certain immune cells, making children more vulnerable to a wide range of infections for years. But measles vaccines also appear to train the immune system in ways that make it more effective on a larger scale. This ripple effect is so beneficial that it has even been suggested that we should continue to vaccinate children against measles even if measles is eliminated.

Of course, it would be too good to be true if all vaccines trained our immune systems in this way. There is evidence that some vaccines have the opposite effect. But that doesn’t mean they don’t save lives overall.

As always with vaccines, the key question to ask is whether getting vaccinated is better than not getting vaccinated. To make an informed choice, you need to balance the risks of infection against vaccination, also considering the wider benefits of a vaccine. Too often, the focus is only on very rare or completely imaginary adverse effects of vaccines.

I have no doubt about what will improve me. I will get my shingles vaccine, a flu shot every year, and at least the RSV vaccine when it is offered.