Merck Receives Warning Letter for Vaccine Operations

The US Food and Drug Administration (FDA) issued a warning letter to Merck and Co. (Whitehouse Station, NJ) on April 28, citing numerous good manufacturing practice (GMP) violations at Merck’s vaccine production operations in West Point, PA. The FDA also requested a meeting with senior management at Merck to discuss the concerns cited in the warning letter.

Vaccines produced at the facility include the human papillomavirus vaccine Gardasil, and the combination measles, mumps, rubella, and chicken pox vaccine ProQuad.
Specific violations noted on the form include:

• Lack of stability information;

• Over-pressurization of vials;

• Validation procedures on certain machines that were not representative of actual inspection process;

• Failure to quarantine process intermediates associated with filter membranes that caused foaming during filtration, which was associated with leaching into process intermediates.

The FDA has stated that it has no reason to believe the problems affected the safety of Merck’s vaccines. The agency also said that the deficiencies would not affect the availability of the vaccines that are manufactured at the West Point facility, with the exception of PedvaxHIB and COMVAX, which were recalled in December 2007.

FDA warning letter