In the comparison with SARS-CoVof 2003,SARS-CoV-2 is extremely well adapted to the human populations and its adaptive shift from the animal host to humans must have been even more extensive.By the blind watchmaker arg...In the comparison with SARS-CoVof 2003,SARS-CoV-2 is extremely well adapted to the human populations and its adaptive shift from the animal host to humans must have been even more extensive.By the blind watchmaker argument,such an adaptive shift can only happen prior to the onset of the current pandemic and with the aid of step-by-step selection.展开更多
Background:The availability of vaccines provides a promising solution to contain the COVID-19 pandemic.However,it remains unclear whether the large-scale vaccination can succeed in containing the COVID-19 pandemic and...Background:The availability of vaccines provides a promising solution to contain the COVID-19 pandemic.However,it remains unclear whether the large-scale vaccination can succeed in containing the COVID-19 pandemic and how soon.We developed an epidemiological model named SUVQC(Suceptible-Unquarantined-Vaccined-Quarantined-Conflrmed)to quantitatively analyze and predict the epidemic dynamics of COVID-19 under vaccination.Methods:In addition to the impact of non-pharmaceutical interventions(NPIs),our model explicitly parameterizes key factors related to vaccination,including the duration of immunity,vaccine efficacy,and daily vaccination rate etc.The model was applied to the daily reported numbers of confirmed cases of Israel and the USA to explore and predict trends under vaccination based on their current epidemic statuses and intervention measures.We further provided a formula for designing a practical vaccination strategy,which simultaneously considers the effects of the basic reproductive number of COVID-19,intensity of NPIs,duration of immunological memory after vaccination,vaccine efficacy and daily vaccination rate.Results:In Israel,53.83%of the population is fully vaccinated,and under the current NPI intensity and vaccination scheme,the pandemic is predicted to end between May 14,2021,and May 16,2021,assuming immunity persists for 180 days to 365 days.If NPIs are not implemented after March 24,2021,the pandemic will end later,between July 4,2021,and August 26,2021.For the USA,if we assume the current vaccination rate(0.268%per day)and intensity of NPIs,the pandemic will end between January 20,2022,and October 19,2024,assuming immunity persists for 180 days to 365 days.However,assuming immunity persists for 180 days and no NPIs are implemented,the pandemic will not end and instead reach an equilibrium state,with a proportion of the population remaining actively infected.Conclusions:Overall,the daily vaccination rate should be decided according to vaccine efficacy and immunity duration to achieve herd immunity.In some situations,vaccination alone cannot stop the pandemic,and NPIs are necessary to supplement vaccination and accelerate the end of the pandemic.Considering that vaccine efficacy and duration of immunity may be reduced for new mutant strains,it is necessary to remain cautiously optimistic about the prospect of,ending the pandemic under vaccination.展开更多
Dear Editor,Coronaviruses have increasingly become the causal agent of epidemics in humans as well as in domesticated animals(Perlman and Mc Intosh,2020;Wu et al.,2021).Since the beginning of this century,there have b...Dear Editor,Coronaviruses have increasingly become the causal agent of epidemics in humans as well as in domesticated animals(Perlman and Mc Intosh,2020;Wu et al.,2021).Since the beginning of this century,there have been 3 such epidemics.展开更多
文摘In the comparison with SARS-CoVof 2003,SARS-CoV-2 is extremely well adapted to the human populations and its adaptive shift from the animal host to humans must have been even more extensive.By the blind watchmaker argument,such an adaptive shift can only happen prior to the onset of the current pandemic and with the aid of step-by-step selection.
基金This study was supported by the National Key R&D Program of China(No.2020YFC0847000)the National Natural Science Foundation of China(Nos.31571370,91731302 and 31772435).
文摘Background:The availability of vaccines provides a promising solution to contain the COVID-19 pandemic.However,it remains unclear whether the large-scale vaccination can succeed in containing the COVID-19 pandemic and how soon.We developed an epidemiological model named SUVQC(Suceptible-Unquarantined-Vaccined-Quarantined-Conflrmed)to quantitatively analyze and predict the epidemic dynamics of COVID-19 under vaccination.Methods:In addition to the impact of non-pharmaceutical interventions(NPIs),our model explicitly parameterizes key factors related to vaccination,including the duration of immunity,vaccine efficacy,and daily vaccination rate etc.The model was applied to the daily reported numbers of confirmed cases of Israel and the USA to explore and predict trends under vaccination based on their current epidemic statuses and intervention measures.We further provided a formula for designing a practical vaccination strategy,which simultaneously considers the effects of the basic reproductive number of COVID-19,intensity of NPIs,duration of immunological memory after vaccination,vaccine efficacy and daily vaccination rate.Results:In Israel,53.83%of the population is fully vaccinated,and under the current NPI intensity and vaccination scheme,the pandemic is predicted to end between May 14,2021,and May 16,2021,assuming immunity persists for 180 days to 365 days.If NPIs are not implemented after March 24,2021,the pandemic will end later,between July 4,2021,and August 26,2021.For the USA,if we assume the current vaccination rate(0.268%per day)and intensity of NPIs,the pandemic will end between January 20,2022,and October 19,2024,assuming immunity persists for 180 days to 365 days.However,assuming immunity persists for 180 days and no NPIs are implemented,the pandemic will not end and instead reach an equilibrium state,with a proportion of the population remaining actively infected.Conclusions:Overall,the daily vaccination rate should be decided according to vaccine efficacy and immunity duration to achieve herd immunity.In some situations,vaccination alone cannot stop the pandemic,and NPIs are necessary to supplement vaccination and accelerate the end of the pandemic.Considering that vaccine efficacy and duration of immunity may be reduced for new mutant strains,it is necessary to remain cautiously optimistic about the prospect of,ending the pandemic under vaccination.
基金supported by the National Natural Science Foundation of China(81802939,32150006,31730046,and 81972691)the National Key Research and Development Projects of the Ministry of Science and Technology of China(2021YFC2301300)+4 种基金the National Key Research and Development Program of China(2021YFC0863400)Guangdong Basic and Applied Basic Research Foundation(2020B1515020030)the National Key Research and Development Project(2020YFC0847000)the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(ZhuhaiNo.311021006)。
文摘Dear Editor,Coronaviruses have increasingly become the causal agent of epidemics in humans as well as in domesticated animals(Perlman and Mc Intosh,2020;Wu et al.,2021).Since the beginning of this century,there have been 3 such epidemics.