Respiratory syncytial virus is a single-stranded RNA virus in the 
Paramyxoviridae family that preferentially assembles and buds from the apical 
surface of polarized epithelial cells, forming filamentous structures that 
contain both viral proteins and the genomic RNA. Recent studies have described 
both viral and host factors that are involved in ribonucleoprotein assembly and 
trafficking of viral proteins to the cell surface. At the cell surface, viral 
proteins assemble into filaments that probably require interactions between 
viral proteins, host proteins and the cell membrane. Finally, a membrane 
scission event must occur to release the free virion. This article will review 
the recent literature describing the mechanisms that drive respiratory syncytial 
virus assembly and budding.