TABLE 28.

Respiratory syncytial virus challenge strains^a

Challenge strain	Method of production and administration	Stock producers
RSV A2	An RSV Genogroup A strain was isolated from a pediatric patient in Melbourne, Australia. The virus was expanded by three passages in Vero cells in culture. Healthy adults were challenged via intranasal instillation.	Walter Reed Army Institute of Research and U.S. National Institute of Allergy and Infectious Diseases
RSV A Memphis-37	An RSV genogroup A strain was isolated from a pediatric patient in Tennessee, United States, and produced in Vero cells. Healthy adults were challenged via intranasal instillation.	Meridian Life Sciences, Inc., and Retroscreen Virology, Ltd.

^aRSV, respiratory syncytial virus.