RESUMEN
INTRODUCTION: The WHO regularly updates influenza vaccine recommendations to maximize their match with circulating strains. Nevertheless, the effectiveness of the influenza A vaccine, specifically its H3N2 component, has been low for several seasons. The aim of the study is to develop a mathematical model of cross-immunity based on the array of published WHO hemagglutination inhibition assay (HAI) data. MATERIALS AND METHODS: In this study, a mathematical model was proposed, based on finding, using regression analysis, the dependence of HAI titers on substitutions in antigenic sites of sequences. The computer program we developed can process data (GISAID, NCBI, etc.) and create real-time databases according to the set tasks. RESULTS: Based on our research, an additional antigenic site F was identified. The difference in 1.6 times the adjusted R2, on subsets of viruses grown in cell culture and grown in chicken embryos, demonstrates the validity of our decision to divide the original data array by passage histories. We have introduced the concept of a degree of homology between two arbitrary strains, which takes the value of a function depending on the Hamming distance, and it has been shown that the regression results significantly depend on the choice of function. The provided analysis showed that the most significant antigenic sites are A, B, and E. The obtained results on predicted HAI titers showed a good enough result, comparable to similar work by our colleagues. CONCLUSION: The proposed method could serve as a useful tool for future forecasts, with further study to confirm its sustainability.
Asunto(s)
Vacunas contra la Influenza , Gripe Humana , Embrión de Pollo , Animales , Humanos , Subtipo H3N2 del Virus de la Influenza A/genética , Vacunas contra la Influenza/genética , Antígenos Virales/genética , Epítopos , Modelos Teóricos , Gripe Humana/epidemiología , Gripe Humana/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza , Estaciones del AñoRESUMEN
The possibility of using a mathematic model of influenza epidemic in evaluation of effectiveness of an etiotropic preparation cagocel for prophylaxis and therapy of influenza as well as determination of possible damage from influenza epidemics and outbreaks in major cities of Russia is shown.
Asunto(s)
Epidemias , Gripe Humana/tratamiento farmacológico , Modelos Teóricos , Gosipol/análogos & derivados , Gosipol/uso terapéutico , Humanos , Gripe Humana/epidemiología , Gripe Humana/prevención & control , PronósticoRESUMEN
The paper gives the results of calculation-theoretical studies estimating the effect of the etiotropic agent Relenza (in preventing influenza in its susceptible patients an in treating patients ill with influenza) on the epidemic of pandemic A(H1N1)/2009 influenza in a large city of Russia. The values of its effect (the number of prevented cases of influenza and that of prevented deaths from its complications) have been calculated on a computer, by applying a modified PSEEI2RF influenza epidemic model (a Russian Baroyan-Rvachev model) with the A(H1N1)/2009 influenza pathogen that dominated in the 2009-2010 season in many countries of the world. Predictive estimates of the action of Relenza on the epidemic of A(H1N1)/2009 influenza have been obtained for 5 scenarios while implementing measures to treat patients with the illness and to prevent its susceptible patients in a large city with a population of one million. In conclusion, there are results of predicting the number of prevented A(H1N1)/2009 influenza cases and damage estimates for 6 cities of Russia due to the massive use of the antiviral drug Relenza.
