WHO informal consultation on characterization and quality aspect of vaccines based on live viral vectors, December 2003
Scope of the Consultation
It was agreed that the following areas should provide the main focus for discussion:
- Vectored vaccines derived from attenuated viral vaccines (i.e., chimeric live vaccines based on attenuated Yellow fever virus - YFV),
- Vaccines based on replication-restricted-poxviruses (i.e., avian poxviruses, attenuated vaccinia virus strains), -adenoviruses, parvoviruses (i.e. adeno-associated viruses - AAV) and -herpesviruses expressing heterologous antigen-encoding genes, possibly in combination with immune stimulator-encoding genes,
- Vaccines based on alphavirus replicon vector particles expressing heterologous antigen-encoding genes (e.g., replication-defective viral replicon particles derived from Semliki Forest virus (SFV), Venezuelan equine encephalitis virus (VEE) and Sindbis virus (SIN)) ,
- Prime-boost vaccination approaches involving the sequential administration of vaccine types itemized in i) to iii).
The development of such vaccines is primarily for prophylactic use against infectious diseases, but they can also be considered for use as post-infection or therapeutic vaccines against infectious diseases and tumours.
Other vectors, including virus-like particle (VLP) vaccines and retroviral carrier-based vaccines with antigen display structures (e.g. murine leukemia virus {MuLV}-display vaccines) and those based on prokaryotic cells (e.g. Salmonella typhimurium) or eukarytotic cells (e.g. dendritic cells) were considered out of scope for the Consultation.