A nationwide shingles vaccine shortage is apparently getting worse because of the partial government shutdown, says U.S. Sen. Charles Schumer.

Pharmacies are struggling to keep the vaccine Shingrix in stock.

The Centers for Disease Control and Prevention says the new vaccine is 97 percent effective at preventing the painful rash and blisters associated with shingles. The virus typically strikes people who have had chicken pox and are now in their 50s.

Schumer says the Food and Drug Administration could not do anything to help because it's working with a limited staff amid the shutdown.

Shingrix is made by the pharmaceutical company GlaxoSmithKline.