ABSTRACT
A comparative study of the immunizing activity of strain variants derived from one epidemic influenza virus A/USSR/77 (H1N1) by using different attenuation methods was carried out. Serial passages in chick embryos preserved the biological activity of the virus better than genetic recombination which was manifested by a significant superiority of the passaged virus over the reassortant in the capacity of replicating in the upper respiratory tracts of the vaccinees, of inducing immune responses and creating the protection of the portals of entry of infection. The problem of optimal preservation of biological potentials of influenza virus in the process of attenuation is discussed.
Subject(s)
Influenza A virus/genetics , Influenza Vaccines/immunology , Recombination, Genetic , Adult , Animals , Antibodies, Viral/analysis , Chick Embryo , Drug Evaluation , Humans , Immunization, Secondary , Influenza A virus/immunology , Influenza Vaccines/adverse effects , Influenza Vaccines/isolation & purification , Influenza, Human/immunology , Influenza, Human/prevention & control , Male , Serial Passage , Time FactorsABSTRACT
A comparative evaluation of immunological and epidemiological effectiveness of commercial live and killed vaccine preparations used simultaneously or separately was first carried out in simultaneous field trials of various methods of influenza vaccine prevention in a human population of 10,449 subjects. The advantage of simultaneous immunization was confirmed by immunological parameters and protective effect in the period of influenza A epidemic of 1983. The correlation of immunological and epidemiological effectiveness of influenza vaccines in joint or separate administration is discussed.
Subject(s)
Immunization/methods , Influenza Vaccines/immunology , Influenza, Human/prevention & control , Absenteeism , Adolescent , Adult , Antibodies, Viral/analysis , Clinical Trials as Topic , Humans , Influenza A virus/immunology , Influenza, Human/epidemiology , Russia , Seasons , Vaccines, Attenuated/immunologyABSTRACT
A significant increase in immunological effectiveness of simultaneous immunization with a killed and live influenza vaccine as compared with separate use of these preparations has been demonstrated. The simultaneous immunization better protected the upper respiratory tracts of the vaccinated volunteers, inhibiting reproduction of the challenge influenza virus with residual virulence. A live vaccine from the "old" influenza A/6/50 (H1N1) was found to produce a protective effect on the current influenza A/1977 (H1N1) virus with residual virulence.
