Emily
Editor, Senior Moderator
https://www.medrxiv.org/content/10.1101/2021.01.07.21249353v1
Inherent random fluctuations in COVID-19 outbreaks may explain rapid growth of new mutated virus variants
Kenneth Bodin, Joacim Rockl?v
medRxiv 2021.01.07.21249353; doi: https://doi.org/10.1101/2021.01.07.21249353 This article is a preprint and has not been peer-reviewed [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.
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Our simulation experiment indicates, given that the modelling assumptions would hold in reality, that there is a probability that any post-facto observed virus variant, such as the VOC 202012/01, can in fact be the product of just a very successful random transmission chain trajectory without alternations in the transmissibility, at least this is probable to happen by chance to some degree. Here we show that 20.4% of the transmission trajectories show at least an Re shift of +0.4 higher than the average. It is important to adjust for this in future studies of changes in transmissibility and Re values of new virus variants, such as VOC 202012/01. This said, the simulations indicate that the longer the generations are run, pattern stagnates, and this may be less of a problem in situations where the number of generations observed are very large. Finally, we want to stress that we are not providing any empirical proof in any way that the VOC 202012/01 is not more transmissible, it may well be, but we do show that there is a bias when observing post facto successful virus variants, which need to be adjusted for in any data analysis of transmissibility. This has bearing for emerging strains and policy implications for COVID-19, as well as for other infectious diseases, especially those exhibiting substantial inhomogeneous spreading patterns....
Inherent random fluctuations in COVID-19 outbreaks may explain rapid growth of new mutated virus variants
Kenneth Bodin, Joacim Rockl?v
medRxiv 2021.01.07.21249353; doi: https://doi.org/10.1101/2021.01.07.21249353 This article is a preprint and has not been peer-reviewed [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.
.....
Our simulation experiment indicates, given that the modelling assumptions would hold in reality, that there is a probability that any post-facto observed virus variant, such as the VOC 202012/01, can in fact be the product of just a very successful random transmission chain trajectory without alternations in the transmissibility, at least this is probable to happen by chance to some degree. Here we show that 20.4% of the transmission trajectories show at least an Re shift of +0.4 higher than the average. It is important to adjust for this in future studies of changes in transmissibility and Re values of new virus variants, such as VOC 202012/01. This said, the simulations indicate that the longer the generations are run, pattern stagnates, and this may be less of a problem in situations where the number of generations observed are very large. Finally, we want to stress that we are not providing any empirical proof in any way that the VOC 202012/01 is not more transmissible, it may well be, but we do show that there is a bias when observing post facto successful virus variants, which need to be adjusted for in any data analysis of transmissibility. This has bearing for emerging strains and policy implications for COVID-19, as well as for other infectious diseases, especially those exhibiting substantial inhomogeneous spreading patterns....