Why I’m Getting a Flu Shot

Four years ago, I wrote a shocking confession…

“This is the year I might finally get a flu shot.”

My longtime readers were understandably surprised to hear me say this. For years, I argued that flu shots were unsafe and unnecessary. I never got one because I was always in great health and I have a robust immune system.

But I’ve started to rethink my position. This year, I’m again planning to get my flu shot.

So what changed my mind?

It turns out that folks who regularly get the flu shot lower their risk of a heart attack.

Fighting off influenza stresses your immune system. When you’re fighting off the virus, inflammation increases, particularly in your blood vessels.

More and more studies show that increases in inflammation lead to blockages… which ultimately leads to heart attacks or strokes.

What’s more, the flu causes your blood vessels to leak fluid, which builds up in your lungs. That fluid may start to grow bacteria, causing deadly infections. It also means you’re getting less oxygen into your blood, that in turn puts a strain on your heart.

In 2016, a review from the University of New South Wales published in BMJ found that the flu vaccine can reduce the risk of a heart attack by 15% to 45% (depending on a person’s other risk factors). The review directly pointed to the increase in inflammation the flu causes and an increased risk of heart attack. Researchers found that mice infected with influenza showed evidence of inflammation directly on their hearts.

A 2018 study published in The New England Journal of Medicine looked at documented cases of the flu with proper laboratory confirmation. Researchers then looked at these patients over the course of a year prior to their diagnosis of flu and a year after.

What they found is that for the seven-day period after a flu diagnosis, people are six times more likely to suffer a heart attack. That was regardless of any present risk factors for heart disease.

But what about long-term protection?

It turns out that when your body creates antibodies to the flu vaccine, those antibodies flip on a receptor in our heart. It’s called the bradykinin b2 receptor. The protein it works with, bradykinin, is an inflammatory marker. Triggering this receptor reduces inflammation and seemingly protects heart tissue.

Researchers are now studying different types of flu vaccines to develop a possible vaccine for heart disease. This is really exciting. Regular readers and friends know I’ve long thought that most diseases we face are infectious. I’ve been laughed at because of my thoughts about the connection between infection and diseases like heart disease and age-related macular degeneration.

The vaccine also offers some protection against getting the flu, though some folks are quick to point out low effectiveness rates. These rates don’t measure one important outcome, though – fewer hospitalizations and deaths. You might still get the flu, but the vaccine will reduce your symptoms and help you avoid the most serious outcomes.

As we get into flu season, consider getting your vaccine. I still advise that if you’re a healthy adult – without heart disease risk factors – chances are you don’t need the vaccine. Our immune systems are built to fight off such illnesses. But if you’re in a group that’s at a higher risk for complications, you should get a flu shot. That includes:

  • Folks aged 65 and older
  • Those with a compromised immune system (including autoimmune diseases like Crohn’s and those undergoing cancer treatments)
  • Those who have heart disease or are at risk of heart attack
  • Pregnant women
  • Babies and young children

Similarly, if you’re around someone who falls into one of those groups, consider getting a vaccine. For instance, if you’re caring for someone recovering from chemotherapy, you don’t want to risk exposing them. Complications for these folks can be life-threatening or fatal.

What We’re Reading

Here’s to our health, wealth, and a great retirement,

Dr. David Eifrig and the Health & Wealth Bulletin Research Team
October 7, 2021