https://www.science.org/content/article/why-flu-vaccines-so-often-failThe influenza virus has yet to hit the Northern Hemisphere, but flu vaccine season is already in full swing, with banners outside pharmacies urging: "Get Your Flu Shot Now." What's not advertised,
however, is just how lackluster the vaccine is. The most commonly used flu shots protect no more than 60% of people who receive them;
some years, effectiveness plunges to as low as 10%. Given that a bad flu season can kill 50,000 people in the United States alone, "10% to 60% protection is better than nothing," says Michael Osterholm, an epidemiologist at the University of Minnesota in Minneapolis.
"But it's a terribly inadequate vaccine for a serious public health threat." Now, researchers are striving to understand why it fails so often—and how to make a markedly better one.