The 6-year-old shingles vaccine is one of the newest immunizations on the market and also one of the most popular, which has created a persistent manufacturing shortage.
The shortage surfaced almost immediately after the Centers for Disease Control and Prevention recommended that most Americans over age 60 get vaccinated to prevent shingles.
The vaccine, licensed in 2006, can prevent shingles, a painful skin rash that often appears with blisters. In clinical trials, the vaccine prevented shingles in about half of people 60 years of age and older, according to the CDC. The vaccine can also reduce the pain associated with shingles.