The Universal Flu Vaccine

By: Dr. Brian Byrd

Every year since I was a kid we would get our annual flu shot in November or December. It struck me as odd that the shots for measles and polio lasted a lifetime but I needed the flu shot every year. What was going on?

Decades ago, we anticipated 90% protection for those who were vaccinated, a lofty anticipation. In reality, the overall benefit was about 60% and for seniors, in particular, it was 40%. While 40% is a low grade on a high school exam, it isn’t terrible in the world of public health. In a year when, say 60,000 people might die from flu, preventing 4 out of ten deaths would mean 24,000 lives saved. Why is the flu vaccine so less effective than other kinds of vaccines?

The answer is that like children, viruses come in different personalities. Some spread through the air like COVID, and others cannot. Some cause sandpaper rashes, others cause bruising. Some never change and others mutate constantly, like influenza, which is the central answer to my earlier question about the effectiveness and repeating shots.

What would solve the annual problem is a shot that had to be given just once every ten years, like a tetanus booster, and would be 90-100% effective, much better than our current 40-60%. Laboratories all over the world are working to overcome this problem, and many are the U.S.- based. What strategy are they using to get there?

Everyone is familiar with the COVID spike, that broccoli-shaped stalk punching out from the virus's surface. Our mRNA vaccines target proteins on the spike’s tips. Similarly, the flu virus has a surface structure shaped like a miniature fruit tree. We load up annual flu shots to aim at whatever fruit the tree is producing this year. It is anyone’s best guess as to what kind of fruit will emanate year to year. Staying with our fruit tree metaphor, some years it is oranges, and others it is pomegranates.

The most promising vaccines induce our immune systems to take out the tree’s trunk which doesn’t mutate (not very much, at least) instead of the fruit which varies year to year. There are more than 10 in investigation and a couple is into human trials. One of the slowing factors peculiar to this work is that to reach “Universal Vaccine” status, the shots have to be tested in humans over several flu seasons.

mRNA technology does not produce our current vaccines nor does it factor into many of the Universal Flu vaccine efforts, but that will change. Some believe it will be the bridge over the water for us. One researcher, Peter Pelese who holds the Chair of Immunology at the Icahn School of Medicine at Mount Sinai in New York said, “If we would spend as much money for flu as we have allocated for COVID-19, we would be there already, in my opinion.”