During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has beco...During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has become the dominant circulating strain worldwide within just a few months. Here, we performed a comprehensive analysis of a new B.1.617.2 Delta strain(Delta630) compared with the early WIV04 strain(WIV04) in vitro and in vivo, in terms of replication, infectivity, pathogenicity, and transmission in hamsters. When inoculated intranasally, Delta630 led to more pronounced weight loss and more severe disease in hamsters. Moreover, 40%mortality occurred about one week after infection with 10^(4)PFU of Delta630, whereas no deaths occurred even after infection with 10^(5)PFU of WIV04 or other strains belonging to the Delta variant. Moreover, Delta630outgrew over WIV04 in the competitive aerosol transmission experiment. Taken together, the Delta630 strain showed increased replication ability, pathogenicity, and transmissibility over WIV04 in hamsters. To our knowledge, this is the first SARS-CoV-2 strain that causes death in a hamster model, which could be an asset for the efficacy evaluation of vaccines and antivirals against infections of SARS-CoV-2 Delta strains. The underlying molecular mechanisms of increased virulence and transmission await further analysis.展开更多
Objective:This study aimed to observe the clinical and immune response characteristics of vaccinated persons infected with the delta variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in Yangzhou,Ch...Objective:This study aimed to observe the clinical and immune response characteristics of vaccinated persons infected with the delta variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in Yangzhou,China.Methods:We extracted the medical data of 129 patients with delta-variant infection who were admitted to Northern Jiangsu People’s Hospital(Yangzhou,China)between August and September,2021.The patients were grouped according to the number of vaccine doses received into an unvaccinated group:a one-dose group and a two-dose group.The vaccine used was SARS-CoV-2-inactivated vaccine developed by Sinovac.We retrospectively analyzed the patients’epidemiological,clinical,laboratory,and imaging data.Results:Almost all patients with delta-variant infection in Yangzhou were elderly,and patients with severe/critical illness were over 70 years of age.The rates of severe/critical illness(P=0.006),fever(P=0.025),and dyspnea(P=0.045)were lower in the two-dose group than in the unvaccinated group.Compared to the unvaccinated group,the two-dose group showed significantly higher lymphocyte counts and significantly lower levels of C-reactive protein(CRP),interleukin-6(IL-6),and D-dimer during hospitalization and a significantly higher positive rate of immunoglobulin G(IgG)antibodies at admission(all P<0.05).The cumulative probabilities of hospital discharge and negative virus conversion were also higher in the two-dose group than in the unvaccinated group(P<0.05).Conclusions:Two doses of the SARS-CoV-2-inactivated vaccine were highly effective at limiting symptomatic disease and reducing immune response,while a single dose did not seem to be effective.展开更多
Wastewater surveillance has been applied in various parts of the world to monitor the introduction and transmissions of SARS-CoV-2 variants in a population. The knowledge of SARS-CoV-2 variants circulating in a popula...Wastewater surveillance has been applied in various parts of the world to monitor the introduction and transmissions of SARS-CoV-2 variants in a population. The knowledge of SARS-CoV-2 variants circulating in a population is critical to COVID-19 management and timing of the application of public health countermeasures. Contrary to the routine clinical surveillance of SARS-CoV-2 where cases from asymptomatic patients are often underreported, wastewater surveillance offers an unbiased tool for monitoring the extent of SARS-CoV-2 transmissions in a community. The present study aimed to characterize SARS-CoV-2 variants that circulated in Nairobi County, Kenya, between April 2021 and August 2021 utilizing wastewater samples. Viral RNA was extracted from wastewater samples, followed by SARS-CoV-2 screening by real-time RT-qPCR before targeted sequencing of the Spike gene. Forty samples were analyzed, of which 50% (n = 20) tested positive for SARS-CoV-2 by real-time RT-qPCR. Of these, 45% (n = 9) were successfully amplified by RT-PCR and sequenced. The majority (78%, 7/9) of the viruses belonged to the Delta (B.1.617.2) lineage of SARS-CoV-2, while a minority (22%) belonged to the Alpha (B.1.1.7) and Alpha-Delta lineages. Phylogenetic analysis of the SARS-COV-2 delta lineage strains revealed scattered clustering of the Kenyan viruses among the global strains included in the analysis, suggesting different introductory routes into the country. On the whole, our results confirm previous clinical findings that SARS-CoV-2 variants belonging to the Alpha (B.1.1.7) and Delta (B.1.617.2) lineages circulated in Nairobi County, Kenya during the study period, with the latter predominating. This is the first study to describe the diversity of SARS-CoV-2 variants circulating in Kenya, through wastewater analysis.展开更多
BACKGROUND The coronavirus disease 2019(COVID-19)virus has been a world-known pan-demic since February 2020.Multiple variances had been established;the most common variants in Israel were omicron and delta.AIM To anal...BACKGROUND The coronavirus disease 2019(COVID-19)virus has been a world-known pan-demic since February 2020.Multiple variances had been established;the most common variants in Israel were omicron and delta.AIM To analyze and compare laboratory values in the"omicron"and"delta"variants of the coronavirus by conducting follow-up examinations and laboratory audits on COVID-19 patients admitted to our institution.METHODS A retrospective study,two groups,50 patients in each group.Patients examined positive for COVID-19 were divided into groups according to the common variant at the given time.We reviewed demographic data and laboratory results such as complete blood count and full chemistry,including electrolytes and coagulation parameters.RESULTS The mean age was 52%,66.53±21.7 were female.No significance was found comparing laboratory results in the following disciplines:Blood count,hemo-globin,and lymphocytes(P=0.41,P=0.87,P=0.97).Omicron and delta variants have higher neutrophil counts,though they are not significantly different(P=0.38).Coagulation tests:Activated paritial thromoplastin test and international normalized ratio(P=0.72,P=0.68).We found no significance of abnormality for all electrolytes.CONCLUSION The study compares laboratory results of blood tests between two variants of the COVID-19 virus–omicron and delta.We found no significance between the variants.Our results show the need for further research with larger data as well as the need to compare all COVID-19 variants.展开更多
Objective:To explore the epidemiological characteristics of Corona Virus Disease 2019(COVID-19)Delta variant infection in children in Xi'an and Baoji.Methods:According to the official information released by Shaan...Objective:To explore the epidemiological characteristics of Corona Virus Disease 2019(COVID-19)Delta variant infection in children in Xi'an and Baoji.Methods:According to the official information released by Shaanxi Province,the information of confirmed cases in Xi'an(December 20,2021 to January 8,2022)and Baoji(March 8 to March 27,2022)were collected respectively.Records include age,sex,residential address,community and other basic information.Isolation mode,isolation time,morbidity and positive time of viral nucleic acid test,vaccination,clinical typing,close contact personnel,cluster incidence situation and the social activity tracking of the confirmed cases were collected,and the data were statistically analyzed.Results:In 20 days,there were 281 infected children in Xi'an,accounting for 14.48%of the total cases(1,940 cases),including 154 boys(54.8%)and 127 girls(45.20%).The number of diagnosed children in Baoji City(55 cases)is 19.57%of that in Xi'an(55/281),but accounts for 23.31%of the total number of cases(236 cases)in Baoji(this ratio is higher than that of 14.48%in Xi'an).Among the 55 cases of children,there are 33 males(60.00%)and 22 females(40.00%).The proportion of male children in both cities is higher.The median age of diagnosed children in Xi'an was 7.0 years(IQR:1.0-13.0 years old),and the age range was 4 d-18 years old,while the median age of Baoji children was 9.0 years old(IQR:5.0-17.0 years old),ranging from 3 months to 18 years old.The number of children vaccinated in Xi'an and Baoji was positively correlated with the number of infected children.The vaccination rates of children in Xi'an and Baoji were 64.06%and 52.73%,respectively.The vaccination rates of infants(≤1 year old)in both cities were 18.52%and 14.29%,respectively.On the whole,the number of new child cases in the two cities increased first and then decreased.The peak number of new child cases in Xi'an was 39(10th day of statistics),while that of Baoji was 13(6th day of statistics).The peak in Xi'an comes later and the epidemic lasts longer.Among the children in Xi'an,201(71.53%)had a history of close contact,55(19.57%)had no clear history of COVID-19 infection,and were positive after actively participating in the nucleic acid test of all members of the community,of which 54(98.18%)were primary and middle school students.54 cases(98.18%)of Baoji children had a history of close contact,of which 20 cases were infected by the confirmed case number 62 officially announced on March 10.The time to be positive for viral nucleic acid test in children after isolation was 1-14 days.The positive rate of children in Xi'an reached 85.41%(240/281)after 7 days of isolation,and the highest peak of positive detection was on the third day of isolation(84 cases).After 7 days of isolation,45 cases were positive in Baoji,accounting for 81.82%(45/55).The highest peak of positive detection was on the 5th day of isolation(11 cases).The regional distribution of infected children in Xi'an was the highest in Yanta District(137 cases),followed by High-tech Zone(42 cases)and Lianhu District(29 cases).The main manifestations of COVID-19 in Xi'an were light(278 cases,98.93%),common type(3 cases,1.07%),light in Baoji(54 cases,98.18%),and common type(1 case,1.82%).Through general clinical treatment(including traditional Chinese medicine treatment and symptomatic treatment),all were cured.Conclusion:Delta variant increases the susceptibility of children to infection,which spreads rapidly mainly through close family contact and community concealment,so it is necessary to study better early diagnosis and prevention and control measures.展开更多
The SARS-CoV-2 Delta variant has evolved as the dominant strain of the current pandemic.Studies have shown that this variant has increased infectivity/viral load,and reduced neutralization by the host antibodies from ...The SARS-CoV-2 Delta variant has evolved as the dominant strain of the current pandemic.Studies have shown that this variant has increased infectivity/viral load,and reduced neutralization by the host antibodies from convalescent patients/vaccinees.Clinically,Delta variant infection has been observed/documented in convalescent patients/vaccinees,although with less incidence of severe diseases,but can serve as reservoir to spread the infection to the unvaccinated.The current understanding(as of 18 August 2021)on the virologic aspect(including the amino acid substitutions),clinical implications,and public health implications will be discussed in this mini review,and recommendations to health authorities will be provided.展开更多
Background Delta and Omicron are two main variants that have been prevalent since 2021.However,the Omicron variant of severe acute respiratory syndrome coronavirus 2 shows a less severe clinical presentation and high ...Background Delta and Omicron are two main variants that have been prevalent since 2021.However,the Omicron variant of severe acute respiratory syndrome coronavirus 2 shows a less severe clinical presentation and high transmissibility.Therefore,we carried out this retrospective study to evaluate Omicron severity compared with the Delta variant and further comprehend the differences in clinical characteristics in patients with the Omicron variant.Methods We extracted clinical data and compared clinical severity,symptoms,vaccination status,laboratory parameters,viral shedding time,and computed tomography(CT)imaging between the two groups of patients,which included 109 COVID-19 cases with the Delta variant and 183 cases with the Omicron variant,from January 19 to April 1,2022,in Beijing Ditan Hospital.In addition,the Beijing Center for Disease Prevention and Control conducted whole-genome sequencing.Results We obtained 94 strains of variants of concern/Delta and 110 strains of variants of concern/Omicron.For the 110 Omicron strains,three were assigned as BA.1.1,53 as BA.2,and 54 as BA.2.2.Among patients with the Delta variant,54%(59/109)were moderate,which was significantly higher than that of patients with the Omicron variant(7%(12/183),P<0.001).The number of patients with mild symptoms in the Omicron group was significantly higher than in the Delta group(80%vs.35%,P<0.001).Compared with the Omicron group,patients with underlying diseases or obesity,60 years or older,or unvaccinated in the Delta group had more severe disease,and there was a significant difference between the two groups.The viral shedding time in the Omicron group was shorter than in the Delta group((11.9±5.9)vs.(14.0±5.8)days,P=0.003).Among the 183 patients in the Omicron group,104(57%)had dry or sore throat symptoms,more than those in the Delta group(34%(37/109);P<0.001).In the Delta group,patients in the moderate group had more fever and cough symptoms than those in the mild group.The remission time of CT imaging in the Omicron group was shorter than in the Delta group((9.0±5.2)vs.(13.2±4.2)days,P=0.018).Conclusions Patients with Delta variants are more likely to have pneumonia,mainly with fever and cough symptoms,while patients with the Omicron variant are mostly mild,with more prominent dry or sore throat symptoms.In addition,patients with the Omicron variant have a short viral shedding time and rapid absorption of pneumonia.展开更多
BACKGROUND The B.1.617.2(delta)variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first discovered in Maharashtra in late 2020 and has rapidly expanded across India and worldwide.It took only 2 ...BACKGROUND The B.1.617.2(delta)variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first discovered in Maharashtra in late 2020 and has rapidly expanded across India and worldwide.It took only 2 mo for this variant to spread in Indonesia,making the country the new epicenter of the delta variant as of July 2021.Despite efforts made by accelerating massive rollouts of current vaccines to protect against infection,cases of fully-vaccinated people infected with the delta variant have been reported.AIM To describe the demographic statistics and clinical presentation of the delta variant infection after the second dose of vaccine in Indonesia.METHODS A retrospective,single-centre case series of the general consecutive population that worked or studied at Faculty of Medicine,Universitas Indonesia with confirmed Delta Variant Infection after a second dose of vaccine from 24 June and 25 June 2021.Cases were collected retrospectively based on a combination of author recall,reverse transcription-polymerase chain reaction(RT-PCR),and whole genome sequencing results from the Clinical Microbiology Laboratory,Faculty of Medicine,Universitas Indonesia.RESULTS Between 24 June and 25 June 2021,15 subjects were confirmed with the B.1.617.2(delta)variant infection after a second dose of the vaccine.Fourteen subjects were vaccinated with CoronaVac(Sinovac)and one subject with ChAdOx1 nCoV-19(Oxford-AstraZeneca).All of the subjects remained in home isolation,with fever being the most common symptom at the onset of illness(n=10,66.67%).The mean duration of symptoms was 7.73 d(±5.444).The mean time that elapsed from the first positive swab to a negative RT-PCR test for SARS-CoV-2 was 17.93 d(±6.3464).The median time that elapsed from the second dose of vaccine to the first positive swab was 87 d(interquartile range:86-128).CONCLUSION Although this case shows that after two doses of vaccine,subjects are still susceptible to the delta variant infection,currently available vaccines remain the most effective protection.They reduce clinical manifestations of COVID-19,decrease recovery time from the first positive swab to negative swab,and lower the probability of hospitalization and mortality rate compared to unvaccinated individuals.展开更多
基金supported by China Natural Science Foundation (82150201)
文摘During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has become the dominant circulating strain worldwide within just a few months. Here, we performed a comprehensive analysis of a new B.1.617.2 Delta strain(Delta630) compared with the early WIV04 strain(WIV04) in vitro and in vivo, in terms of replication, infectivity, pathogenicity, and transmission in hamsters. When inoculated intranasally, Delta630 led to more pronounced weight loss and more severe disease in hamsters. Moreover, 40%mortality occurred about one week after infection with 10^(4)PFU of Delta630, whereas no deaths occurred even after infection with 10^(5)PFU of WIV04 or other strains belonging to the Delta variant. Moreover, Delta630outgrew over WIV04 in the competitive aerosol transmission experiment. Taken together, the Delta630 strain showed increased replication ability, pathogenicity, and transmissibility over WIV04 in hamsters. To our knowledge, this is the first SARS-CoV-2 strain that causes death in a hamster model, which could be an asset for the efficacy evaluation of vaccines and antivirals against infections of SARS-CoV-2 Delta strains. The underlying molecular mechanisms of increased virulence and transmission await further analysis.
基金the National Natural Science Foundation of China(Nos.82171207 and 82172190)the Jiangsu Association for Science and Technology Young Scientific and Technological Talents Support Project(No.2021008)+1 种基金the Jiangsu Province“333”High-level Talents Training Project(No.2022-3-6-146)the Yangzhou Science and Technology Plan Project(Nos.YZ2021088 and YZ2021148)。
文摘Objective:This study aimed to observe the clinical and immune response characteristics of vaccinated persons infected with the delta variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in Yangzhou,China.Methods:We extracted the medical data of 129 patients with delta-variant infection who were admitted to Northern Jiangsu People’s Hospital(Yangzhou,China)between August and September,2021.The patients were grouped according to the number of vaccine doses received into an unvaccinated group:a one-dose group and a two-dose group.The vaccine used was SARS-CoV-2-inactivated vaccine developed by Sinovac.We retrospectively analyzed the patients’epidemiological,clinical,laboratory,and imaging data.Results:Almost all patients with delta-variant infection in Yangzhou were elderly,and patients with severe/critical illness were over 70 years of age.The rates of severe/critical illness(P=0.006),fever(P=0.025),and dyspnea(P=0.045)were lower in the two-dose group than in the unvaccinated group.Compared to the unvaccinated group,the two-dose group showed significantly higher lymphocyte counts and significantly lower levels of C-reactive protein(CRP),interleukin-6(IL-6),and D-dimer during hospitalization and a significantly higher positive rate of immunoglobulin G(IgG)antibodies at admission(all P<0.05).The cumulative probabilities of hospital discharge and negative virus conversion were also higher in the two-dose group than in the unvaccinated group(P<0.05).Conclusions:Two doses of the SARS-CoV-2-inactivated vaccine were highly effective at limiting symptomatic disease and reducing immune response,while a single dose did not seem to be effective.
文摘Wastewater surveillance has been applied in various parts of the world to monitor the introduction and transmissions of SARS-CoV-2 variants in a population. The knowledge of SARS-CoV-2 variants circulating in a population is critical to COVID-19 management and timing of the application of public health countermeasures. Contrary to the routine clinical surveillance of SARS-CoV-2 where cases from asymptomatic patients are often underreported, wastewater surveillance offers an unbiased tool for monitoring the extent of SARS-CoV-2 transmissions in a community. The present study aimed to characterize SARS-CoV-2 variants that circulated in Nairobi County, Kenya, between April 2021 and August 2021 utilizing wastewater samples. Viral RNA was extracted from wastewater samples, followed by SARS-CoV-2 screening by real-time RT-qPCR before targeted sequencing of the Spike gene. Forty samples were analyzed, of which 50% (n = 20) tested positive for SARS-CoV-2 by real-time RT-qPCR. Of these, 45% (n = 9) were successfully amplified by RT-PCR and sequenced. The majority (78%, 7/9) of the viruses belonged to the Delta (B.1.617.2) lineage of SARS-CoV-2, while a minority (22%) belonged to the Alpha (B.1.1.7) and Alpha-Delta lineages. Phylogenetic analysis of the SARS-COV-2 delta lineage strains revealed scattered clustering of the Kenyan viruses among the global strains included in the analysis, suggesting different introductory routes into the country. On the whole, our results confirm previous clinical findings that SARS-CoV-2 variants belonging to the Alpha (B.1.1.7) and Delta (B.1.617.2) lineages circulated in Nairobi County, Kenya during the study period, with the latter predominating. This is the first study to describe the diversity of SARS-CoV-2 variants circulating in Kenya, through wastewater analysis.
文摘BACKGROUND The coronavirus disease 2019(COVID-19)virus has been a world-known pan-demic since February 2020.Multiple variances had been established;the most common variants in Israel were omicron and delta.AIM To analyze and compare laboratory values in the"omicron"and"delta"variants of the coronavirus by conducting follow-up examinations and laboratory audits on COVID-19 patients admitted to our institution.METHODS A retrospective study,two groups,50 patients in each group.Patients examined positive for COVID-19 were divided into groups according to the common variant at the given time.We reviewed demographic data and laboratory results such as complete blood count and full chemistry,including electrolytes and coagulation parameters.RESULTS The mean age was 52%,66.53±21.7 were female.No significance was found comparing laboratory results in the following disciplines:Blood count,hemo-globin,and lymphocytes(P=0.41,P=0.87,P=0.97).Omicron and delta variants have higher neutrophil counts,though they are not significantly different(P=0.38).Coagulation tests:Activated paritial thromoplastin test and international normalized ratio(P=0.72,P=0.68).We found no significance of abnormality for all electrolytes.CONCLUSION The study compares laboratory results of blood tests between two variants of the COVID-19 virus–omicron and delta.We found no significance between the variants.Our results show the need for further research with larger data as well as the need to compare all COVID-19 variants.
文摘Objective:To explore the epidemiological characteristics of Corona Virus Disease 2019(COVID-19)Delta variant infection in children in Xi'an and Baoji.Methods:According to the official information released by Shaanxi Province,the information of confirmed cases in Xi'an(December 20,2021 to January 8,2022)and Baoji(March 8 to March 27,2022)were collected respectively.Records include age,sex,residential address,community and other basic information.Isolation mode,isolation time,morbidity and positive time of viral nucleic acid test,vaccination,clinical typing,close contact personnel,cluster incidence situation and the social activity tracking of the confirmed cases were collected,and the data were statistically analyzed.Results:In 20 days,there were 281 infected children in Xi'an,accounting for 14.48%of the total cases(1,940 cases),including 154 boys(54.8%)and 127 girls(45.20%).The number of diagnosed children in Baoji City(55 cases)is 19.57%of that in Xi'an(55/281),but accounts for 23.31%of the total number of cases(236 cases)in Baoji(this ratio is higher than that of 14.48%in Xi'an).Among the 55 cases of children,there are 33 males(60.00%)and 22 females(40.00%).The proportion of male children in both cities is higher.The median age of diagnosed children in Xi'an was 7.0 years(IQR:1.0-13.0 years old),and the age range was 4 d-18 years old,while the median age of Baoji children was 9.0 years old(IQR:5.0-17.0 years old),ranging from 3 months to 18 years old.The number of children vaccinated in Xi'an and Baoji was positively correlated with the number of infected children.The vaccination rates of children in Xi'an and Baoji were 64.06%and 52.73%,respectively.The vaccination rates of infants(≤1 year old)in both cities were 18.52%and 14.29%,respectively.On the whole,the number of new child cases in the two cities increased first and then decreased.The peak number of new child cases in Xi'an was 39(10th day of statistics),while that of Baoji was 13(6th day of statistics).The peak in Xi'an comes later and the epidemic lasts longer.Among the children in Xi'an,201(71.53%)had a history of close contact,55(19.57%)had no clear history of COVID-19 infection,and were positive after actively participating in the nucleic acid test of all members of the community,of which 54(98.18%)were primary and middle school students.54 cases(98.18%)of Baoji children had a history of close contact,of which 20 cases were infected by the confirmed case number 62 officially announced on March 10.The time to be positive for viral nucleic acid test in children after isolation was 1-14 days.The positive rate of children in Xi'an reached 85.41%(240/281)after 7 days of isolation,and the highest peak of positive detection was on the third day of isolation(84 cases).After 7 days of isolation,45 cases were positive in Baoji,accounting for 81.82%(45/55).The highest peak of positive detection was on the 5th day of isolation(11 cases).The regional distribution of infected children in Xi'an was the highest in Yanta District(137 cases),followed by High-tech Zone(42 cases)and Lianhu District(29 cases).The main manifestations of COVID-19 in Xi'an were light(278 cases,98.93%),common type(3 cases,1.07%),light in Baoji(54 cases,98.18%),and common type(1 case,1.82%).Through general clinical treatment(including traditional Chinese medicine treatment and symptomatic treatment),all were cured.Conclusion:Delta variant increases the susceptibility of children to infection,which spreads rapidly mainly through close family contact and community concealment,so it is necessary to study better early diagnosis and prevention and control measures.
文摘The SARS-CoV-2 Delta variant has evolved as the dominant strain of the current pandemic.Studies have shown that this variant has increased infectivity/viral load,and reduced neutralization by the host antibodies from convalescent patients/vaccinees.Clinically,Delta variant infection has been observed/documented in convalescent patients/vaccinees,although with less incidence of severe diseases,but can serve as reservoir to spread the infection to the unvaccinated.The current understanding(as of 18 August 2021)on the virologic aspect(including the amino acid substitutions),clinical implications,and public health implications will be discussed in this mini review,and recommendations to health authorities will be provided.
基金supported by the Chang Jiang Scholars program(2019077).
文摘Background Delta and Omicron are two main variants that have been prevalent since 2021.However,the Omicron variant of severe acute respiratory syndrome coronavirus 2 shows a less severe clinical presentation and high transmissibility.Therefore,we carried out this retrospective study to evaluate Omicron severity compared with the Delta variant and further comprehend the differences in clinical characteristics in patients with the Omicron variant.Methods We extracted clinical data and compared clinical severity,symptoms,vaccination status,laboratory parameters,viral shedding time,and computed tomography(CT)imaging between the two groups of patients,which included 109 COVID-19 cases with the Delta variant and 183 cases with the Omicron variant,from January 19 to April 1,2022,in Beijing Ditan Hospital.In addition,the Beijing Center for Disease Prevention and Control conducted whole-genome sequencing.Results We obtained 94 strains of variants of concern/Delta and 110 strains of variants of concern/Omicron.For the 110 Omicron strains,three were assigned as BA.1.1,53 as BA.2,and 54 as BA.2.2.Among patients with the Delta variant,54%(59/109)were moderate,which was significantly higher than that of patients with the Omicron variant(7%(12/183),P<0.001).The number of patients with mild symptoms in the Omicron group was significantly higher than in the Delta group(80%vs.35%,P<0.001).Compared with the Omicron group,patients with underlying diseases or obesity,60 years or older,or unvaccinated in the Delta group had more severe disease,and there was a significant difference between the two groups.The viral shedding time in the Omicron group was shorter than in the Delta group((11.9±5.9)vs.(14.0±5.8)days,P=0.003).Among the 183 patients in the Omicron group,104(57%)had dry or sore throat symptoms,more than those in the Delta group(34%(37/109);P<0.001).In the Delta group,patients in the moderate group had more fever and cough symptoms than those in the mild group.The remission time of CT imaging in the Omicron group was shorter than in the Delta group((9.0±5.2)vs.(13.2±4.2)days,P=0.018).Conclusions Patients with Delta variants are more likely to have pneumonia,mainly with fever and cough symptoms,while patients with the Omicron variant are mostly mild,with more prominent dry or sore throat symptoms.In addition,patients with the Omicron variant have a short viral shedding time and rapid absorption of pneumonia.
文摘BACKGROUND The B.1.617.2(delta)variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first discovered in Maharashtra in late 2020 and has rapidly expanded across India and worldwide.It took only 2 mo for this variant to spread in Indonesia,making the country the new epicenter of the delta variant as of July 2021.Despite efforts made by accelerating massive rollouts of current vaccines to protect against infection,cases of fully-vaccinated people infected with the delta variant have been reported.AIM To describe the demographic statistics and clinical presentation of the delta variant infection after the second dose of vaccine in Indonesia.METHODS A retrospective,single-centre case series of the general consecutive population that worked or studied at Faculty of Medicine,Universitas Indonesia with confirmed Delta Variant Infection after a second dose of vaccine from 24 June and 25 June 2021.Cases were collected retrospectively based on a combination of author recall,reverse transcription-polymerase chain reaction(RT-PCR),and whole genome sequencing results from the Clinical Microbiology Laboratory,Faculty of Medicine,Universitas Indonesia.RESULTS Between 24 June and 25 June 2021,15 subjects were confirmed with the B.1.617.2(delta)variant infection after a second dose of the vaccine.Fourteen subjects were vaccinated with CoronaVac(Sinovac)and one subject with ChAdOx1 nCoV-19(Oxford-AstraZeneca).All of the subjects remained in home isolation,with fever being the most common symptom at the onset of illness(n=10,66.67%).The mean duration of symptoms was 7.73 d(±5.444).The mean time that elapsed from the first positive swab to a negative RT-PCR test for SARS-CoV-2 was 17.93 d(±6.3464).The median time that elapsed from the second dose of vaccine to the first positive swab was 87 d(interquartile range:86-128).CONCLUSION Although this case shows that after two doses of vaccine,subjects are still susceptible to the delta variant infection,currently available vaccines remain the most effective protection.They reduce clinical manifestations of COVID-19,decrease recovery time from the first positive swab to negative swab,and lower the probability of hospitalization and mortality rate compared to unvaccinated individuals.
