Objective:To determine the real-world effectiveness of the ChAdOx1 nCoV-19 coronavirus vaccine in preventing severe disease and mortality due to COVID-19.Methods:A case-case design was used to estimate the effect of t...Objective:To determine the real-world effectiveness of the ChAdOx1 nCoV-19 coronavirus vaccine in preventing severe disease and mortality due to COVID-19.Methods:A case-case design was used to estimate the effect of the ChAdOx1 nCoV-19 coronavirus vaccine on severe SARS-CoV-2 outcomes in individuals aged 40 years and above.Cases(n=200)were COVID-19 patients admitted to intensive care unit(ICU)or who died.Controls(n=223)were those with mild COVID-19,fit for home isolation.The logistic regression model was used to estimate adjusted vaccine effectiveness for full vaccination(two doses≥14 d)and partial vaccination status(one dose≥14 d or two doses<14 d).Results:The proportion of fully vaccinated individuals was significantly lower among cases(12,6.0%)compared to controls(30,13.5%).The adjusted effectiveness of a full dose of ChAdOx1 nCoV-19 coronavirus vaccine in preventing ICU admission or death was 81.9%(95%CI:61.3%-91.6%,P=0.001).Subgroup analysis restricted to age group,sex,and comorbidities found that ChAdOx1 nCoV-19 coronavirus vaccine had a significant positive effect in all subgroups and categories.Conclusion:COVID-19 vaccination reduces ICU admissions or death.Therefore,increased vaccine uptake may reduce the severity of the pandemic,more so in the elderly and those with comorbidities.展开更多
Objective:To study the transmission dynamics of coronavirus disease 2019(COVID-19)among 101 confirmed cases and their 387 household contacts and to determine risk factors associated with secondary attack among the hou...Objective:To study the transmission dynamics of coronavirus disease 2019(COVID-19)among 101 confirmed cases and their 387 household contacts and to determine risk factors associated with secondary attack among the household contacts.Methods:A prospective cohort study was conducted from January 1st 2021 to February 28th 2021,among 101 SARS-CoV-2 cases and 387 household contacts who were followed up for 14 days from the last day of contact with the index case of COVID-19.The dynamics of disease transmission was estimated,and factors affecting transmission risk were analyzed.Besides,the association between various factors and household secondary attack rate was determined.Results:The median incubation period was found to be 5 days,and the observed reproductive number(R)was found to be 1.63(95%CI:1.28-1.98).The mean household secondary attack rate was 40.7%.Contacts with comorbidities like diabetes mellitus,hypertension,dyslipidemia,and hypothyroidism had significantly higher attack rates(P<0.05).Conclusions:As new variants of SARS-CoV-2 emerges,it is crucial to know the trasmission dynamics.This study shows a high secondary attack rate of COVID-19 among household contacts that must be closely monitored.展开更多
文摘Objective:To determine the real-world effectiveness of the ChAdOx1 nCoV-19 coronavirus vaccine in preventing severe disease and mortality due to COVID-19.Methods:A case-case design was used to estimate the effect of the ChAdOx1 nCoV-19 coronavirus vaccine on severe SARS-CoV-2 outcomes in individuals aged 40 years and above.Cases(n=200)were COVID-19 patients admitted to intensive care unit(ICU)or who died.Controls(n=223)were those with mild COVID-19,fit for home isolation.The logistic regression model was used to estimate adjusted vaccine effectiveness for full vaccination(two doses≥14 d)and partial vaccination status(one dose≥14 d or two doses<14 d).Results:The proportion of fully vaccinated individuals was significantly lower among cases(12,6.0%)compared to controls(30,13.5%).The adjusted effectiveness of a full dose of ChAdOx1 nCoV-19 coronavirus vaccine in preventing ICU admission or death was 81.9%(95%CI:61.3%-91.6%,P=0.001).Subgroup analysis restricted to age group,sex,and comorbidities found that ChAdOx1 nCoV-19 coronavirus vaccine had a significant positive effect in all subgroups and categories.Conclusion:COVID-19 vaccination reduces ICU admissions or death.Therefore,increased vaccine uptake may reduce the severity of the pandemic,more so in the elderly and those with comorbidities.
文摘Objective:To study the transmission dynamics of coronavirus disease 2019(COVID-19)among 101 confirmed cases and their 387 household contacts and to determine risk factors associated with secondary attack among the household contacts.Methods:A prospective cohort study was conducted from January 1st 2021 to February 28th 2021,among 101 SARS-CoV-2 cases and 387 household contacts who were followed up for 14 days from the last day of contact with the index case of COVID-19.The dynamics of disease transmission was estimated,and factors affecting transmission risk were analyzed.Besides,the association between various factors and household secondary attack rate was determined.Results:The median incubation period was found to be 5 days,and the observed reproductive number(R)was found to be 1.63(95%CI:1.28-1.98).The mean household secondary attack rate was 40.7%.Contacts with comorbidities like diabetes mellitus,hypertension,dyslipidemia,and hypothyroidism had significantly higher attack rates(P<0.05).Conclusions:As new variants of SARS-CoV-2 emerges,it is crucial to know the trasmission dynamics.This study shows a high secondary attack rate of COVID-19 among household contacts that must be closely monitored.
