Every year since 2010, the US Centers for Disease Control and Prevention has recommended that everyone in the country ages 6 months and older receive a flu vaccine.
But that has resulted in just fewer than half of all adults and about 58% of kids getting the shot each year, according to CDC data.
Covid-19 vaccines have a ways to go to catch up. Just 21% of US adults received a bivalent booster, the last version available before the US Food and Drug Administration authorized an updated Covid vaccine this month. Among kids, the numbers are much lower: less than 8% of everyone under 18.