The various applications of poxvirus-vectored vaccines will, either directly or indirectly, result in release or escape to the environment. The high environmental resistance of poxviruses gives ample opportunity for long-term survival within, and secondary spread out of, the initially contaminated focus or biotope. The most notable putative environmental risks related to poxvirus-vectored vaccines are: a) infection of non target species and b) recombinations between naturally occurring and vaccine viruses.

The distribution and characteristics of poxviruses in different parts of the world have not been systematically studied. Norway makes an exception in this regard, since one has demonstrated that 2 Norwegian orthopoxvirus isolates are unique, and may be hybrids between Vaccina virus Lister and a naturally occurring cowpoxvirus strain.

Norwegian avipoxviruses seem to be different from protype virus in a gene supposed to be highly conserved. Infectious viral hybrids were obtained by co-infections in cell cultures with a vaccina virus vectored influenza vaccine and a wildtype Norwegian orthopoxvirus strain. Coinfections have already been carried out in the authentic host species bank vole (Clethrionomys glarelus) and in Balb.c.mice . The materials will now be analyzed by the methods developed during cell culture experiments. All the investigations and experiments initiated need to be carried on in order to make future vaccine risk assessments on a sounder scientific basis.

Participants in the project:
Terje Traavik, project leader
Malachy Ifeanyi Okeke
Hilde Hansen
Øivind Nilssen