Charred shrink wrap detected in Merck vax vials

The latest snafu at Merck's West Point, PA, vaccines plant shows just how tough it can be to fix manufacturing problems once they begin. After a series of quality-control issues and reporting shortfalls, charred particles of shrink wrap have been found in some West Point vials, the Wall Street Journal reports. The products affected include the human papillomavirus shot Gardasil, the chicken pox vaccine Varivax, and the pneumococcal vaccine Pneumovax.

Merck said the particles were found at a reported rate of less than one in 6 million vials, and that it's not aware of any adverse events linked to the problem. The company also said vaccines that contain particles could trigger a reaction at the injection site, but neither sterility nor potency should be compromised. FDA said, however, that safety risks from the shrink wrap bits can't be ruled out. The company has submitted at least a dozen reports to FDA about charred shrink wrap found in vaccines, some prompted by customer complaints.

As the Journal points out, FDA issued a warning letter in 2008 highlighting problems at the West Point plant. Since then, agency inspectors have found more problems: metal particles in vials, cracked vials, plus delays in required adverse-event reports to FDA. None of those resulted in another warning letter, however, and Merck officials said they've made progress. "What we are seeing is that the severity and criticality of observations [by FDA inspectors] are declining," Merck's vaccines VP James Robinson told the WSJ. "What we've seen in the last few inspections tells us we're on the right track."

Unfortunately, Merck is far from alone in finding particles in injectable drugs. Particulate contamination has touched off a series of warning letters and even recalls in recent months. Flu vaccine maker CSL was cited by FDA for dark particles found in its multi-dose vials. Johnson & Johnson and Takeda Pharmaceutical recalled vials of the blood cancer drug Velcade after visible particles were found. Glass bits have been identified in several companies' injectable products, prompting several recalls. Claris LifeSciences pulled antibiotics and anti-nausea drugs found to contain floating matter. And just last week, silicone particles touched off a recall at American Regent.

- read the WSJ piece