Merck said Wednesday it has received a warning letter from the Food and Drug Administration over deficiencies at one of its major vaccine manufacturing plants.
The company makes a majority of its shots, including Gardasil for cervical cancer, among others, at the plant located in West Point, Pa.
The Food and Drug Administration said it did not believe the manufacturing issues would affect the safety of the company's vaccines. Merck said the warning letter will not hamper its ability to sell currently marketed vaccines.
The letter identifies a dozen issues it wants Merck to address. One of them, for example, involves filter fibers being found on the stopper for a vial.
"We're continuing to address all of the FDA's concerns in a timely and comprehensive manner," a Merck spokesperson told said.
The nine-page warning letter gives Merck 15 days to tell the FDA how it will correct the violations. Otherwise, the FDA says it could suspend the plant's manufacturing license and seize products.
The issues are not affecting manufacturing, Merck said. "We do not distribute contaminated products. We have quality systems in place and we don't release any product that does not meet those standards," said spokesperson Amy Rose.
The plant makes a number of popular children's vaccines, as well as Gardasil, which protects against cervical cancer. Last year, it recalled 1.2 million vaccine doses because of a sterility problem.
Vaccines are a multi-billion-dollar-a-year segment for Merck and a big growth driver for the company.
Merck shares are trading around a multi-year low following the FDA's rejection of a new cholesterol drug earlier this week.
- Wire services contributed to this story.