We couple a simple model of quarantine and testing strategies for international travellers with a model for transmission of SARS-CoV-2 in a partly vaccinated population.We use this model to estimate the risk of an inf...We couple a simple model of quarantine and testing strategies for international travellers with a model for transmission of SARS-CoV-2 in a partly vaccinated population.We use this model to estimate the risk of an infectious traveller causing a community outbreak under various border control strategies and different levels of vaccine coverage in the population.Results are calculated from N¼100,000 independent realisations of the stochastic model.We find that strategies that rely on home isolation are significantly higher risk than the current mandatory 14-day stay in government-managed isolation.Nevertheless,combinations of testing and home isolation can still reduce the risk of a community outbreak to around one outbreak per 100 infected travellers.We also find that,under some circumstances,using daily lateral flow tests or a combination of lateral flow tests and polymerase chain reaction(PCR)tests can reduce risk to a comparable or lower level than using PCR tests alone.Combined with controls on the number of travellers from countries with high prevalence of COVID-19,our results allow different options for managing the risk of COVID-19 at the border to be compared.This can be used to inform strategies for relaxing border controls in a phased way,while limiting the risk of community outbreaks as vaccine coverage increases.展开更多
文摘We couple a simple model of quarantine and testing strategies for international travellers with a model for transmission of SARS-CoV-2 in a partly vaccinated population.We use this model to estimate the risk of an infectious traveller causing a community outbreak under various border control strategies and different levels of vaccine coverage in the population.Results are calculated from N¼100,000 independent realisations of the stochastic model.We find that strategies that rely on home isolation are significantly higher risk than the current mandatory 14-day stay in government-managed isolation.Nevertheless,combinations of testing and home isolation can still reduce the risk of a community outbreak to around one outbreak per 100 infected travellers.We also find that,under some circumstances,using daily lateral flow tests or a combination of lateral flow tests and polymerase chain reaction(PCR)tests can reduce risk to a comparable or lower level than using PCR tests alone.Combined with controls on the number of travellers from countries with high prevalence of COVID-19,our results allow different options for managing the risk of COVID-19 at the border to be compared.This can be used to inform strategies for relaxing border controls in a phased way,while limiting the risk of community outbreaks as vaccine coverage increases.
