The avian influenza (bird flu) virus of the H5N1 subtype continues to infect people, especially in South-Eastern Asia. Until today, it has caused more than 600 human cases, with a mortality rate of over 50%. The virus has a clear potential to cause a worldwide outbreak and therefore poses a major threat to global public health. The development of an effective vaccine is a cornerstone in the preparation for such an H5N1 pandemic. Teams from Rotterdam and Munich have now successfully tested a promising candidate vaccine.
Recent research had suggested the usefulness of a new viral vector vaccine, which was co-developed by the teams of Albert Osterhaus from the Viroscience department of the Erasmus Medical Center Rotterdam and Gerd Sutter from LMU Munich. Now, a first-in-man clinical study funded by the European Research Council and conducted at the Erasmus MC demonstrates the safety and the effectiveness of an H5N1 candidate vaccine in humans. The study involved 80 healthy young volunteers (aged 18-28 years). The candidate vaccine was well tolerated and had no serious adverse events. Compared to low-dose immunization, a standard dose elicited significantly higher levels of antibody responses after one or two immunizations.
About the MVA platform
The new candidate vaccine is based on the poxvirus vaccine platform MVA, a safety tested virus, which is unable to productively replicate in humans. With the aid of molecular biological techniques, researchers insert genetic information from pathogenic viruses – in this case influenza virus H5N1 – into the genome of the MVA. As a result, the H5 protein encoded by these gene sequences is co-produced by the MVA. When this vaccine is injected into animals or human subjects, the H5 antigen can provoke antibody forming and other immune cells that can provide protective immunity to infection.
“This study represents the first clinical trial of an MVA-based H5N1 vaccine. We are very pleased with the performance of the MVA-vector vaccine, in particular with the excellent booster responses obtained one year after primary immunization. This finding further increases our confidence in the value of the MVA platform for rapid development of vaccines in response to new influenza viruses and other emerging pathogens”. – Prof. Ab Osterhaus, Erasmus MC Rotterdam, The Netherlands
Safety and immunogenicity of a modified-vaccinia-virus-Ankara-based influenza A H5N1 vaccine: a randomised, double-blind phase 1/2a clinical trial. Joost H C M Kreijtz, Marco Goeijenbier, Fleur M Moesker, Lennert van den Dries, Simone Goeijenbier, Heidi L M De Gruyter, Michael H Lehmann, Gerrie de Mutsert, David A M C van de Vijver, Asisa Volz, Ron A M Fouchier, Eric C M van Gorp, Guus F Rimmelzwaan, Gerd Sutter, Albert D M E Osterhaus. Lancet Infect Dis ePub 30.10.2014, DOI: 10.1016/S1473-3099(14)70963-6
The research described in this press statement has been conducted in the framework of an ERC Advanced Investigator Grant for the project FLUPLAN (Osterhaus: project number 250136). FLUPLAN is a research project that aims to mitigate the next influenza pandemic by the development of novel intervention strategies against potential pandemic influenza viruses.