Merck's facilities in West Point handle some of the company's research and development of medicine, along with some manufacturing.
"A manufacturing issue related to the glass vial was identified during packaging," Merck spokeswoman Lainie Keller wrote in an e-mail. "The issue has been resolved and preventative measures are in place, and this voluntary recall is being conducted with the concurrence of the FDA. This recall does not affect Merck's ability to supply the market. There is adequate inventory to replace recalled product at this time."
The lot, numbered J001183, consisted of 27,020 vials of the adult formulation and was distributed nationwide by Merck between March 12 and May 2, 2013. Merck also makes a version for children.
Keller said she could not say which wholesalers or pharmacies or doctors got the medicine.
Hepatitis, which involves inflammation of the liver, has several forms.
The Centers for Disease Control and Prevention website says an estimated 800,000 to 1,400,000 people in the United States have chronic hepatitis B virus infection, though many do not know it. Worldwide, chronic hepatitis B affects about 350 million people and contributes to an estimated 620,000 deaths worldwide each year.
The CDC says hepatitis B in the United States has decreased 82 percent since 1990, when routine vaccinations of children began.
Contact David Sell at 215-854-4506, firstname.lastname@example.org, or @phillypharma. Read his blog at www.inquirer.com/phillypharma.