The US Food and Drug Administration is extending the review period for the biologics license application (BLA) for Zostavax (zoster vaccine live), Merck's investigational shingles vaccine, to review additional information that Merck submitted during the review process. The FDA has informed Merck that the agency's new review goal date for the application for Zostavax is May 25, 2006.

According to the company release, Merck filed the BLA for Zostavax with the FDA on April 25, 2005. The company has filed additional regulatory applications for Zostavax in other major markets including the European Union and Australia.