Questionable sterility leads to Hib vaccine recall

December 17, 2007

Merck recalls PedvaxHIB and COMVAX vaccines

Merck & Co. has announced a voluntary recall of its haemophilus b conjugate- containing vaccines, PedvaxHB and COMVAX. The precautionary measure comes after the company identified the presence of bacteria Bacillus cereus on the manufacturing equipment used to produce the vaccines. Although sterility tests of the vaccine lots did not show any contamination, the company issued a recall of 10 lots of PedvaxHIB and two lots of COMVAX. According to the CDC, distribution of the lots began in April 2007 and affects a total of about one million doses that were distributed in the U.S. and to the CDC stockpile. A child immunized with an affected lot could be at increased risk for developing a localized or disseminated infection within one week of vaccination, according to the agency. In addition, immunocompromised patients may be at greater risk for these infections. However, no reports of infection have been detected by the Vaccine Adverse Event Reporting System (VAERS). Efficacy of the vaccines has not been compromised, so children already vaccinated are protected against haemophilus b infection. More information and lot numbers of affected vaccine can be accessed at