Following the heels of approval from the European regulatory authorities, GlaxoSmithKline said it received the U.S. Food and Drug Administration’s go-ahead for its shingles vaccine Shingrix for those aged 50 or older, on Friday.

■ Related : GSK’s shingles vaccine gets 1st approval from Canada

The U.S. approval followed a unanimous 11-0 vote by the FDA advisory committee last month. Clinical trials showed the vaccine to reach a 90 percent efficacy in people over 50 years old for four years, beating out main competitor Merck & Co’s (known as MSD outside the U.S. and Canada) Zostavax on clinical data.

The company said last week that it is still undergoing examination in the EU, Australia, and Japan. The drug is expected to reach annual sales of $1.3 billion by 2023, according to Thomson Reuters’ data, which may propel the drug to blockbuster status.

Shingrix (herpes zoster vaccine) is administered intramuscularly in two doses to help prevent shingles, characterized by painful and blistering rashes. The condition results from the reactivation of the varicella-zoster virus, which also causes chicken-pox.