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COVID-19 Modeling Outcome versus Reality in Sweden

Carlsson, Marcus LU and Söderberg-Nauclér, Cecilia (2022) In Viruses 14(8).
Abstract

It has been very difficult to predict the development of the COVID-19 pandemic based on mathematical models for the spread of infectious diseases, and due to major non-pharmacological interventions (NPIs), it is still unclear to what extent the models would have fit reality in a “do nothing” scenario. To shed light on this question, the case of Sweden during the time frame from autumn 2020 to spring 2021 is particularly interesting, since the NPIs were relatively minor and only marginally updated. We found that state of the art models are significantly overestimating the spread, unless we assume that social interactions significantly decrease continuously throughout the time frame, in a way that does not correlate well with... (More)

It has been very difficult to predict the development of the COVID-19 pandemic based on mathematical models for the spread of infectious diseases, and due to major non-pharmacological interventions (NPIs), it is still unclear to what extent the models would have fit reality in a “do nothing” scenario. To shed light on this question, the case of Sweden during the time frame from autumn 2020 to spring 2021 is particularly interesting, since the NPIs were relatively minor and only marginally updated. We found that state of the art models are significantly overestimating the spread, unless we assume that social interactions significantly decrease continuously throughout the time frame, in a way that does not correlate well with Google-mobility data nor updates to the NPIs or public holidays. This leads to the question of whether modern SEIR-type mathematical models are unsuitable for modeling the spread of SARS-CoV-2 in the human population, or whether some particular feature of SARS-CoV-2 dampened the spread. We show that, by assuming a certain level of pre-immunity to SARS-CoV-2, we obtain an almost perfect data-fit, and discuss what factors could cause pre-immunity in the mathematical models. In this scenario, a form of herd-immunity under the given restrictions was reached twice (first against the Wuhan-strain and then against the alpha-strain), and the ultimate decline in cases was due to depletion of susceptibles rather than the vaccination campaign.

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author
and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
COVID-19, modeling, SARS-CoV-2, SEIR, SIR
in
Viruses
volume
14
issue
8
article number
1840
publisher
MDPI AG
external identifiers
  • pmid:36016462
  • scopus:85137125280
ISSN
1999-4915
DOI
10.3390/v14081840
language
English
LU publication?
yes
id
99058639-2de2-414b-9272-2651aa4b734f
date added to LUP
2022-11-09 15:14:51
date last changed
2024-06-27 16:09:35
@article{99058639-2de2-414b-9272-2651aa4b734f,
  abstract     = {{<p>It has been very difficult to predict the development of the COVID-19 pandemic based on mathematical models for the spread of infectious diseases, and due to major non-pharmacological interventions (NPIs), it is still unclear to what extent the models would have fit reality in a “do nothing” scenario. To shed light on this question, the case of Sweden during the time frame from autumn 2020 to spring 2021 is particularly interesting, since the NPIs were relatively minor and only marginally updated. We found that state of the art models are significantly overestimating the spread, unless we assume that social interactions significantly decrease continuously throughout the time frame, in a way that does not correlate well with Google-mobility data nor updates to the NPIs or public holidays. This leads to the question of whether modern SEIR-type mathematical models are unsuitable for modeling the spread of SARS-CoV-2 in the human population, or whether some particular feature of SARS-CoV-2 dampened the spread. We show that, by assuming a certain level of pre-immunity to SARS-CoV-2, we obtain an almost perfect data-fit, and discuss what factors could cause pre-immunity in the mathematical models. In this scenario, a form of herd-immunity under the given restrictions was reached twice (first against the Wuhan-strain and then against the alpha-strain), and the ultimate decline in cases was due to depletion of susceptibles rather than the vaccination campaign.</p>}},
  author       = {{Carlsson, Marcus and Söderberg-Nauclér, Cecilia}},
  issn         = {{1999-4915}},
  keywords     = {{COVID-19; modeling; SARS-CoV-2; SEIR; SIR}},
  language     = {{eng}},
  number       = {{8}},
  publisher    = {{MDPI AG}},
  series       = {{Viruses}},
  title        = {{COVID-19 Modeling Outcome versus Reality in Sweden}},
  url          = {{http://dx.doi.org/10.3390/v14081840}},
  doi          = {{10.3390/v14081840}},
  volume       = {{14}},
  year         = {{2022}},
}