Changes in symptomatology, reinfection, and transmissibility associated with the SARS-CoV-2 variant B.1.1.7: an ecological study.
Changes in symptomatology, reinfection, and transmissibility associated with the SARS-CoV-2 variant B.1.1.7: an ecological study.
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DOI：
10.1016/s2468-2667(21)00055-4
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发表时间：
2021-05
期刊：
影响因子：
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通讯作者：
Ourselin S
中科院分区：
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作者：
Graham MS;Sudre CH;May A;Antonelli M;Murray B;Varsavsky T;Kläser K;Canas LS;Molteni E;Modat M;Drew DA;Nguyen LH;Polidori L;Selvachandran S;Hu C;Capdevila J;COVID-19 Genomics UK (COG-UK) Consortium;Hammers A;Chan AT;Wolf J;Spector TD;Steves CJ;Ourselin S
SARS-CoV-2变种B.1.1.7于2020年12月在英国首次被发现。我们的目的是调查这种变异感染比例的增加是否与症状或病程、再感染率或传染性的差异有关。我们进行了一项生态学研究，以检查SARS-CoV-2 B.1.1.7变体感染的区域比例与报告的症状，病程，再感染率和传播率之间的关系。有关症状类型和持续时间的数据来自COVID Symptom Study应用程序用户的纵向报告，这些用户在2020年9月28日至12月27日期间报告了COVID-19阳性检测（在此期间，B.1.1.7的患病率在英国部分地区增加最明显）。根据该数据集，我们还估计了可能的再感染频率，定义为存在两次报告的阳性检测，间隔超过90天，并且在第二次阳性检测之前超过7天没有报告症状。使用来自COVID-19 Genomics UK Consortium的基因组数据和来自英格兰公共卫生部的关于英格兰社区病例中刺突基因靶向失败（B.1.1.7变体的非特异性指标）的数据，估计了英国全国B.1.1.7变体SARS-CoV-2感染的比例。我们使用线性回归来检查报告的症状与B.1.1.7比例之间的关联。我们评估了B.1.1.7病例比例与再感染次数之间以及阳性检测次数与再感染次数之间的斯皮尔曼相关性。我们估计了B.1.1.7和之前变体的发生率，并比较了两种发生率估计值的有效繁殖数Rt。2020年9月28日至12月27日，36 920名COVID-19症状研究应用程序用户报告了阳性COVID-19测试，这些用户的地区已知，并在应用程序注册时报告为健康。我们未发现与B.1.1.7相关的报告症状或疾病持续时间的变化。在同一时期，在2020年10月1日之前报告拭子检测阳性的36509名应用程序用户中，有249人（0.7%[95%CI 0.6 - 0.8]）确定了可能的再感染，但没有证据表明B.1.1.7变体的再感染频率高于先前存在的变体。再感染发生率与病例的总体区域上升呈正相关（东南部、伦敦和英格兰东部的斯皮尔曼相关系数为0.56 - 0.69），而不是B.1.1.7变异体感染比例的区域性增加（相同地区的斯皮尔曼相关系数为0.38 - 0.56），表明B.1.1.7不会显著改变再感染的风险。我们发现B.1.1.7的Rt相对于既存变体成倍增加1.35倍（95% CI 1.02 - 1.69）。然而，在区域和国家封锁期间，Rt降至1以下，即使在B.1.1.7变异感染比例高的地区也是如此。本研究中发现的症状没有变化表明，现有的检测和监测基础设施不需要专门针对B.1.1.7变体进行改变。此外，鉴于再感染率没有明显增加，疫苗可能对B.1.1.7变异株仍然有效。Zoe Global，卫生部（英国），Wellcome Trust，工程和物理科学研究理事会（英国），国家健康研究所（英国），医学研究理事会（英国），阿尔茨海默氏症协会。
The SARS-CoV-2 variant B.1.1.7 was first identified in December, 2020, in England. We aimed to investigate whether increases in the proportion of infections with this variant are associated with differences in symptoms or disease course, reinfection rates, or transmissibility. We did an ecological study to examine the association between the regional proportion of infections with the SARS-CoV-2 B.1.1.7 variant and reported symptoms, disease course, rates of reinfection, and transmissibility. Data on types and duration of symptoms were obtained from longitudinal reports from users of the COVID Symptom Study app who reported a positive test for COVID-19 between Sept 28 and Dec 27, 2020 (during which the prevalence of B.1.1.7 increased most notably in parts of the UK). From this dataset, we also estimated the frequency of possible reinfection, defined as the presence of two reported positive tests separated by more than 90 days with a period of reporting no symptoms for more than 7 days before the second positive test. The proportion of SARS-CoV-2 infections with the B.1.1.7 variant across the UK was estimated with use of genomic data from the COVID-19 Genomics UK Consortium and data from Public Health England on spike-gene target failure (a non-specific indicator of the B.1.1.7 variant) in community cases in England. We used linear regression to examine the association between reported symptoms and proportion of B.1.1.7. We assessed the Spearman correlation between the proportion of B.1.1.7 cases and number of reinfections over time, and between the number of positive tests and reinfections. We estimated incidence for B.1.1.7 and previous variants, and compared the effective reproduction number, Rt, for the two incidence estimates. From Sept 28 to Dec 27, 2020, positive COVID-19 tests were reported by 36 920 COVID Symptom Study app users whose region was known and who reported as healthy on app sign-up. We found no changes in reported symptoms or disease duration associated with B.1.1.7. For the same period, possible reinfections were identified in 249 (0·7% [95% CI 0·6–0·8]) of 36 509 app users who reported a positive swab test before Oct 1, 2020, but there was no evidence that the frequency of reinfections was higher for the B.1.1.7 variant than for pre-existing variants. Reinfection occurrences were more positively correlated with the overall regional rise in cases (Spearman correlation 0·56–0·69 for South East, London, and East of England) than with the regional increase in the proportion of infections with the B.1.1.7 variant (Spearman correlation 0·38–0·56 in the same regions), suggesting B.1.1.7 does not substantially alter the risk of reinfection. We found a multiplicative increase in the Rt of B.1.1.7 by a factor of 1·35 (95% CI 1·02–1·69) relative to pre-existing variants. However, Rt fell below 1 during regional and national lockdowns, even in regions with high proportions of infections with the B.1.1.7 variant. The lack of change in symptoms identified in this study indicates that existing testing and surveillance infrastructure do not need to change specifically for the B.1.1.7 variant. In addition, given that there was no apparent increase in the reinfection rate, vaccines are likely to remain effective against the B.1.1.7 variant. Zoe Global, Department of Health (UK), Wellcome Trust, Engineering and Physical Sciences Research Council (UK), National Institute for Health Research (UK), Medical Research Council (UK), Alzheimer's Society.