The FDA found contaminated children's vaccines and other potentially serious concerns at Merck & Co.'s vaccine plant in the Philadelphia suburbs.

The Philadelphia Inquirer reported FDA inspectors found unwanted fibers on vaccine vial stoppers also were among the areas of concern cited

FDA inspectors visited the plant, in West Point in Montgomery County, on 30 separate days from November through January.

In December, Merck recalled 1.2 million doses of its vaccine against Haemophilus influenza type B, made at the same plant, because of a sterility problem discovered in October. It also quarantined nearly a year's worth of other, possibly suspect doses.

Tell us what you think below.