New influenza vaccine based on MVA.

MVA expressing the HA gene from influenza virus A/Vietnam/1194/04 has been studied in depth in mice and a non-human primate model. Initially a two dose immunization regimen was tested in C57Bl6/J mice and induced sterile immunity in these animals against the homologous and heterologous strains.(Kreijtz et al JID 2007) As a follow-up study the two dose regimen was tested in cynomolgus macaques in which it proved to be safe and it induced also sterile immunity against the homologous and heterologous challenge viruses.(Kreijtz et al JID 2009)

In a dose escalation experiment in mice we determined the minimal dose to induce protection against challenge infection and explored the possibility to induce protection with a single immunization. Mice that were immunized once with a relatively high dose (10e8) or twice with a low dose (3log10 lower) were protected against challenge infection with the homologous or heterologous influenza A/H5N1 virus.(Kreijtz et al PLoS One 2009)

MVA-based influenza vaccine is safe and immunogenic in young healthy adults.

1. Before immunization;

2. 1 hour after immunization;

3. 4 weeks after immunization;

4. 4 weeks after second immunization;

5. 20 weeks after second immunization.

1 or 2 intramuscular immunizations with an MVA-based influenza vaccine. Two dosages are tested:

1. 10e7 pfu in 0.5ml;

2. 10e8 pfu in 0.5ml.