Since overcoming supply-constraining manufacturing problems Merck ($MRK) has seen uptake of its shingles vaccine Zostavax rise. Now, with U.S. sales growing and an international rollout underway, the FDA has approved a Merck plant in North Carolina to produce the bulk varicella used in the vaccine.
Merck began building the facility in Durham in 2004 to add to its fill-and-finish capacity. Since then the plant has undergone a series of expansions, culminating in the FDA licensing the facility to manufacture the bulk ingredient used in Zostavax and Merck's chickenpox vaccine, Varivax, this week. The FDA approval comes three years after the agency cleared the facility to fill and finish Varivax, and enables Merck to produce both the bulk and final product at Durham.
Ultimately, Merck plans to equip the plant to handle bulk ingredients and fill/finish for all its childhood vaccines, plus Zostavax. This week's approval for bulk varicella is a step towards that goal. "The licensure of the Durham varicella bulk facility marks a significant milestone for Merck and adds additional manufacturing capabilities," Merck manufacturing division president Willie Deese said. Before securing the license, Merck was producing all global bulk supplies for its varicella-containing vaccines at a plant in West Point, PA.
Having two plants approved to produce bulk varicella equips Merck to handle an expected increase in global demand for vaccines containing the ingredient. This week the U.K. began offering Zostavax to people aged 70 or 79. Around 800,000 people are eligible to receive the vaccine this year, the BBC reports. Over the next few years, the program will expand to encompass more of the 70-to-79 age group. Once this catch-up initiative is complete, people will be offered the vaccine when they turn 70.