Americans over age 60 are often not getting needed immunizations, and that is creating a growing risk to the healthcare system, say federal disease-prevention experts.

About two-thirds of those who are 65 and older have never had the shingles vaccine, and more than 4 in 10 haven’t had a tetanus shot in the past 10 years, according to the Centers for Disease Control and Prevention (CDC). As for the pneumococcal vaccine, nearly a third of older people haven’t had this immunization.