Control, bi-stability, and preference for chaos in time-dependent vaccination campaign

Autor(es)

Gabrick, Enrique C. ; Brugnago, Eduardo L. ; de Moraes, Ana L. R. ; Protachevicz, Paulo R. ; da Silva, Sidney T. ; Borges, Fernando S. ; Caldas, Ibere L. ; Batista, Antonio M. ; Kurths, Juergen

• Tipo de documento: Artigo Científico
• Fonte: Chaos; v. 34, n. 9, p. 13-pg., 2024-09-01.

Resumo

In this work, effects of constant and time-dependent vaccination rates on the Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) seasonal model are studied. Computing the Lyapunov exponent, we show that typical complex structures, such as shrimps, emerge for given combinations of a constant vaccination rate and another model parameter. In some specific cases, the constant vaccination does not act as a chaotic suppressor and chaotic bands can exist for high levels of vaccination (e.g., > 0.95). Moreover, we obtain linear and non-linear relationships between one control parameter and constant vaccination to establish a disease-free solution. We also verify that the total infected number does not change whether the dynamics is chaotic or periodic. The introduction of a time-dependent vaccine is made by the inclusion of a periodic function with a defined amplitude and frequency. For this case, we investigate the effects of different amplitudes and frequencies on chaotic attractors, yielding low, medium, and high seasonality degrees of contacts. Depending on the parameters of the time-dependent vaccination function, chaotic structures can be controlled and become periodic structures. For a given set of parameters, these structures are accessed mostly via crisis and, in some cases, via period-doubling. After that, we investigate how the time-dependent vaccine acts in bi-stable dynamics when chaotic and periodic attractors coexist. We identify that this kind of vaccination acts as a control by destroying almost all the periodic basins. We explain this by the fact that chaotic attractors exhibit more desirable characteristics for epidemics than periodic ones in a bi-stable state. (AU)

• Processo FAPESP: 20/04624-2 - Plasticidade sináptica em redes neuronais
• Beneficiário: Paulo Ricardo Protachevicz
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/03211-6 - Dinâmica não linear
• Beneficiário: Iberê Luiz Caldas
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 23/12863-5 - Sincronização em redes neuronais com plasticidade sináptica de longa duração
• Beneficiário: Paulo Ricardo Protachevicz
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 21/12232-0 - Transporte caótico de partículas
• Beneficiário: Eduardo Luís Brugnago
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 22/13761-9 - Dinâmica de Sistemas Complexos
• Beneficiário: Iberê Luiz Caldas
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Brasil