The Centers for Disease Control and Prevention (CDC) recommends that people 50 and older, including those previously immunized with Zostavax, should now get the new Shingrix vaccine, which was approved by the Food and Drug Administration last October. Studies showed it to be far more effective than Zostavax. According to the CDC, Shingrix can protect 97 percent of people in their 50s and 60s, and 91 percent of those in their 70s and 80s, and it lasts longer. That’s compared to 51 percent by Zostavax, which starts to lose its protection after three years. New York Times medical writer Jane Brody reports the shot is painful and can cause a sore arm for a day or two.