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  1. Article ; Online: Dynamics of an SIRWS model with waning of immunity and varying immune boosting period

    Richmond Opoku-Sarkodie / Ferenc A. Bartha / Mónika Polner / Gergely Röst

    Journal of Biological Dynamics, Vol 16, Iss 1, Pp 596-

    2022  Volume 618

    Abstract: SIRS models capture transmission dynamics of infectious diseases for which immunity is not lifelong. Extending these models by a W compartment for individuals with waning immunity, the boosting of the immune system upon repeated exposure may be ... ...

    Abstract SIRS models capture transmission dynamics of infectious diseases for which immunity is not lifelong. Extending these models by a W compartment for individuals with waning immunity, the boosting of the immune system upon repeated exposure may be incorporated. Previous analyses assumed identical waning rates from R to W and from W to S. This implicitly assumes equal length for the period of full immunity and of waned immunity. We relax this restriction, and allow an asymmetric partitioning of the total immune period. Stability switches of the endemic equilibrium are investigated with a combination of analytic and numerical tools. Then, continuation methods are applied to track bifurcations along the equilibrium branch. We find rich dynamics: Hopf bifurcations, endemic double bubbles, and regions of bistability. Our results highlight that the length of the period in which waning immunity can be boosted is a crucial parameter significantly influencing long term epidemiological dynamics.
    Keywords Waning immunity ; immune boosting ; SIRWS system ; partitioning of immunity ; Hopf bifurcation ; Environmental sciences ; GE1-350 ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2022-12-01T00:00:00Z
    Publisher Taylor & Francis Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Book ; Online: Risk Assessment of Novel Coronavirus COVID-19 Outbreaks Outside China

    Péter Boldog / Tamás Tekeli / Zsolt Vizi / Attila Dénes / Ferenc A. Bartha / Gergely Röst

    Journal of Clinical Medicine ; Volume 9 ; Issue 2

    2020  

    Abstract: We developed a computational tool to assess the risks of novel coronavirus outbreaks outside of China. We estimate the dependence of the risk of a major outbreak in a country from imported cases on key parameters such as: (i) the evolution of the ... ...

    Abstract We developed a computational tool to assess the risks of novel coronavirus outbreaks outside of China. We estimate the dependence of the risk of a major outbreak in a country from imported cases on key parameters such as: (i) the evolution of the cumulative number of cases in mainland China outside the closed areas

    (ii) the connectivity of the destination country with China, including baseline travel frequencies, the effect of travel restrictions, and the efficacy of entry screening at destination

    and (iii) the efficacy of control measures in the destination country (expressed by the local reproduction number R loc ). We found that in countries with low connectivity to China but with relatively high R loc , the most beneficial control measure to reduce the risk of outbreaks is a further reduction in their importation number either by entry screening or travel restrictions. Countries with high connectivity but low R loc benefit the most from policies that further reduce R loc . Countries in the middle should consider a combination of such policies. Risk assessments were illustrated for selected groups of countries from America, Asia, and Europe. We investigated how their risks depend on those parameters, and how the risk is increasing in time as the number of cases in China is growing.
    Keywords novel coronavirus ; transmission ; risk assessment ; interventions ; travel ; outbreak ; COVID-19 ; compartmental model ; branching process ; covid19
    Subject code 950
    Language English
    Publishing date 2020-02-19
    Publisher Multidisciplinary Digital Publishing Institute
    Publishing country ch
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Risk Assessment of Novel Coronavirus COVID-19 Outbreaks Outside China

    Péter Boldog / Tamás Tekeli / Zsolt Vizi / Attila Dénes / Ferenc A. Bartha / Gergely Röst

    Journal of Clinical Medicine, Vol 9, Iss 2, p

    2020  Volume 571

    Abstract: We developed a computational tool to assess the risks of novel coronavirus outbreaks outside of China. We estimate the dependence of the risk of a major outbreak in a country from imported cases on key parameters such as: (i) the evolution of the ... ...

    Abstract We developed a computational tool to assess the risks of novel coronavirus outbreaks outside of China. We estimate the dependence of the risk of a major outbreak in a country from imported cases on key parameters such as: (i) the evolution of the cumulative number of cases in mainland China outside the closed areas; (ii) the connectivity of the destination country with China, including baseline travel frequencies, the effect of travel restrictions, and the efficacy of entry screening at destination; and (iii) the efficacy of control measures in the destination country (expressed by the local reproduction number <math display="inline"> <semantics> <msub> <mi>R</mi> <mi>loc</mi> </msub> </semantics> </math> ). We found that in countries with low connectivity to China but with relatively high <math display="inline"> <semantics> <msub> <mi>R</mi> <mi>loc</mi> </msub> </semantics> </math> , the most beneficial control measure to reduce the risk of outbreaks is a further reduction in their importation number either by entry screening or travel restrictions. Countries with high connectivity but low <math display="inline"> <semantics> <msub> <mi>R</mi> <mi>loc</mi> </msub> </semantics> </math> benefit the most from policies that further reduce <math display="inline"> <semantics> <msub> <mi>R</mi> <mi>loc</mi> </msub> </semantics> </math> . Countries in the middle should consider a combination of such policies. Risk assessments were illustrated for selected groups of countries from America, Asia, and Europe. We investigated how their risks depend on those parameters, and how the risk is increasing in time as the number of cases in China is growing.
    Keywords novel coronavirus ; transmission ; risk assessment ; interventions ; travel ; outbreak ; covid-19 ; compartmental model ; branching process ; Medicine ; R ; covid19
    Subject code 511
    Language English
    Publishing date 2020-02-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Early Phase of the COVID-19 Outbreak in Hungary and Post-Lockdown Scenarios

    Gergely Röst / Ferenc A. Bartha / Norbert Bogya / Péter Boldog / Attila Dénes / Tamás Ferenci / Krisztina J. Horváth / Attila Juhász / Csilla Nagy / Tamás Tekeli / Zsolt Vizi / Beatrix Oroszi

    Viruses, Vol 12, Iss 708, p

    2020  Volume 708

    Abstract: COVID-19 epidemic has been suppressed in Hungary due to timely non-pharmaceutical interventions, prompting a considerable reduction in the number of contacts and transmission of the virus. This strategy was effective in preventing epidemic growth and ... ...

    Abstract COVID-19 epidemic has been suppressed in Hungary due to timely non-pharmaceutical interventions, prompting a considerable reduction in the number of contacts and transmission of the virus. This strategy was effective in preventing epidemic growth and reducing the incidence of COVID-19 to low levels. In this report, we present the first epidemiological and statistical analysis of the early phase of the COVID-19 outbreak in Hungary. Then, we establish an age-structured compartmental model to explore alternative post-lockdown scenarios. We incorporate various factors, such as age-specific measures, seasonal effects, and spatial heterogeneity to project the possible peak size and disease burden of a COVID-19 epidemic wave after the current measures are relaxed.
    Keywords COVID-19 ; epidemic ; Hungary ; under-ascertainment ; SARS-CoV-2 ; compartmental model ; reproduction number ; intervention ; case fatality rate ; Microbiology ; QR1-502 ; covid19
    Subject code 612
    Language English
    Publishing date 2020-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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    Inter-library loan at ZB MED

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