Vaccine Contamination

Adventitious agents in viral vaccines: Lessons learned from 4 case studies

Since the earliest days of biological product manufacture, there have been a number of instances where laboratory studies provided evidence for the presence of adventitious agents in a marketed product. Lessons learned from such events can be used to strengthen regulatory preparedness for the future. We have therefore selected four instances where an adventitious agent, or a signal suggesting the presence of an agent, was found in a viral vaccine, and have developed a case study for each. The four cases are: a) SV40 in polio vaccines; b) bacteriophage in measles and polio vaccines; c) reverse transcriptase in measles and mumps vaccines; and d) porcine circovirus and porcine circovirus DNA sequences in rotavirus vaccines. The lessons learned from each event are discussed. Based in part on those experiences, certain scientific principles have been identified by WHO that should be considered in regulatory risk evaluation if an adventitious agent is found in a marketed vaccine in the future.

Read entire paper:

– Biologicals Volume 42, Issue 5, September 2014, Pages 223–236)

– or download pdf: Petriccianai-Biologicals-2014-adventitious agent lessons learned


Victoria, et al, Journal of Virology (2010) found:

“In vaccines grown in chicken embryo fibroblast (CEF), signals to avian endogenous retrovirus (AEV) were detected. The anticipated detection of AEV reflects the presence of multiple loci of these endogenous proviruses in the chicken germ line (8, 9), release of AEV viral particles into CEF-derived vaccines (15, 34, 38), as well as possible cross-hybridization with ALV sequences, since the more conserved region of related viral groups are used in the microarray. The detection of human endogenous retrovirus K (HERVK) in Varivax, MMR-II, and Meruvax was the expected consequence of their manufacture using human cell lines (Table (Table2).2). The origin of the baboon endogenous retrovirus signal for Rotateq is assumed to be related to the African green monkey-derived Vero cell used in its manufacture and cross-hybridization of its endogenous retroviruses to the baboon endogenous retrovirus probes.” Link to study:

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from page 18 – fda-2012-cell-lines