NICEATM holds workshop on new safety tests for pertussis vaccines
By Debbie McCarley and Cathy Sprankle
NIEHS and U.S. Food and Drug Administration (FDA) scientists joined other experts from around the world at a workshop to consider improved methods and approaches for safety testing of vaccines that protect against pertussis. The “International Workshop on Alternatives to the Murine Histamine Sensitization Test (HIST) for Acellular Pertussis Vaccines: State of the Science and the Path Forward” was held Nov. 28-29, 2012, at the William H. Natcher Conference Center on the NIH campus in Bethesda, Md.
The workshop provided a forum for participants to review protocols and available data from an ongoing international study of in vitro alternatives for safety testing of pertussis vaccines. The workshop participants also considered the next steps to achieve validation, global acceptance, and implementation of these test methods.
The NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) organized the workshop in collaboration with the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) and partner organizations of the International Cooperation on Alternative Test Methods. .
Pertussis is an important public health concern
Pertussis, also known as whooping cough, is a highly contagious bacterial disease that was once a major cause of childhood mortality. While widespread vaccination has substantially decreased the incidence of pertussis, recent outbreaks have led public health officials to recommend renewed and expanded vaccination efforts.
The HIST is a key safety test performed on pertussis vaccines, to prevent adverse effects from residual pertussis toxin that has not been completely inactivated. However, the testing uses a large number of animals, and many of the animals experience pain and distress. Therefore, NICEATM and ICCVAM identified the HIST as a priority for future research, development, and validation of alternative test methods that could reduce, refine, or replace animal use for pertussis vaccine safety testing.
Given the need for alternatives to the HIST, an international committee of regulatory and industry experts was established to evaluate animal replacement methods that could also provide greater accuracy, precision, and efficiency. The committee initiated an international collaborative study on in vitro alternatives to the HIST. In this study, reference pertussis toxin and seven acellular pertussis vaccines from three manufacturers were distributed to 12 international laboratories for testing. Data were generated on the detection of pertussis toxin in toxin-spiked vaccines using conventional high-performance liquid chromatography and enzyme-linked immunosorbent assay platforms, as well as advanced cell-based and genomics technologies.
Workshop participants reviewed data from this study. Based on the findings, regulatory, manufacturing, and other scientific attendees selected two of the cell-based methods for further development and optimization in the next international collaborative study planned for later this year.
“Both vaccine manufacturers and regulators are actively working to develop and validate improved alternatives that can achieve acceptance and use,” noted William Stokes, D.V.M., who participated in the workshop in his role as director of NICEATM. “This is an important opportunity to reduce animal use and improve safety testing with a test that has a clear impact on public health.”
A more detailed summary of the workshop and speaker presentations are available on the ICCVAM website. A report on the workshop will be appear later this year in the journal Biologicals.
(Debbie McCarley is a special assistant to Stokes. Cathy Sprankle is a communications specialist with ILS Inc., support contractor for NICEATM.)