mva-based h5n1 vaccine affords cross-clade protection in mice against influenza ah5n1 viruses at low doses and after single immunizationmva-based h5n1疫苗提供ah5n1 cross-clade保护小鼠免受流感病毒后在低剂量和免疫.pdfVIP

MVA-Based H5N1 Vaccine Affords Cross-Clade Protection in Mice against Influenza A/H5N1 Viruses at Low Doses and after Single Immunization 1 2 1 1 2 Joost H. C. M. Kreijtz , Yasemin Suezer , Gerrie de Mutsert , Geert van Amerongen , Astrid Schwantes , 1 1 ¨ 2 1 Judith M. A. van den Brand , Ron A. M. Fouchier , Johannes Lower , Albert D. M. E. Osterhaus , Gerd 2,3 1 Sutter , Guus F. Rimmelzwaan * ¨ ¨ 1 Department of Virology, Erasmus Medical Center, Rotterdam, The Netherlands, 2 Paul-Ehrlich-Institut, Langen, Germany, 3 Ludwig-Maximilians-Universitat, Munchen, Germany Abstract Human infections with highly pathogenic avian influenza viruses of the H5N1 subtype, frequently reported since 2003, result in high morbidity and mortality. It is feared that these viruses become pandemic, therefore the development of safe and effective vaccines is desirable. MVA-based H5N1 vaccines already proved to be effective when two immunizations with high doses were used. Dose-sparing strategies would increase the number of people that can be vaccinated when the amount of vaccine preparations that can be produced is limited. Furthermore, protective immunity is induced ideally after a single immunization. Therefore the minimal requirements for induction of protective immunity with a MVA-based H5N1 vaccine were assessed in mice. To this end, mice were vaccinated once or twice with descending doses of a r