​​Zostavax became the first shingles vaccine to be approved by the U.S. Food and Drug Administration (FDA) in 2006. FDA. Zostavax is administered as a shot to the upper and works using a live, but weakened form, of the varicella-zoster virus to decrease the risk of shingles. The varicella-zoster virus also causes chickenpox in children.
It was thought to be highly effective at the time and Zostavax seemed to be an important breakthrough in the containment of the disease. Zostavax would help Merck earn nearly $750 million in profits over the next 12 years.