[Live influenza vaccines (author's transl)].

Recent progress in live influenza A vaccine research is reviewed. As vaccine strains with new antigenic determinants have to be available in a short time, methods for rapid and reproducible attenuation of wild strains are needed. The possibilities for attenuation of influenza A wild strains and their relative merits are discussed. Particular problems arise from the fact that in interpandemic periods the population is composed of individuals with varying degrees of immunity. Vaccine strains of different virulence or different dosages for nonimmune and partially immune segments of the population may be necessary. Vaccine trials of the last few years are reviewed and the future uses of live influenza vaccines are discussed.