Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, Wisconsin, United States of America.
Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America.
PLoS Pathog. 2022 Sep 30;18(9):e1010876. doi: 10.1371/journal.ppat.1010876. eCollection 2022 Sep.
The SARS-CoV-2 Delta Variant of Concern is highly transmissible and contains mutations that confer partial immune escape. The emergence of Delta in North America caused the first surge in COVID-19 cases after SARS-CoV-2 vaccines became widely available. To determine whether individuals infected despite vaccination might be capable of transmitting SARS-CoV-2, we compared RT-PCR cycle threshold (Ct) data from 20,431 test-positive anterior nasal swab specimens from fully vaccinated (n = 9,347) or unvaccinated (n = 11,084) individuals tested at a single commercial laboratory during the interval 28 June- 1 December 2021 when Delta variants were predominant. We observed no significant effect of vaccine status alone on Ct value, nor when controlling for vaccine product or sex. Testing a subset of low-Ct (<25) samples, we detected infectious virus at similar rates, and at similar titers, in specimens from vaccinated and unvaccinated individuals. These data indicate that vaccinated individuals infected with Delta variants are capable of shedding infectious SARS-CoV-2 and could play a role in spreading COVID-19.
令人关注的 SARS-CoV-2 德尔塔变异株具有高度传染性，并包含部分免疫逃逸的突变。德尔塔在北美出现，导致 COVID-19 病例在 SARS-CoV-2 疫苗广泛使用后首次激增。为了确定接种疫苗后仍被感染的个体是否能够传播 SARS-CoV-2，我们比较了在一家商业实验室在 2021 年 6 月 28 日至 12 月 1 日期间进行的 20,431 例前鼻拭子阳性标本的 RT-PCR 循环阈值 (Ct) 数据，这些标本来自完全接种疫苗的个体（n = 9,347）或未接种疫苗的个体（n = 11,084）。我们发现疫苗接种状态本身对 Ct 值没有显著影响，也没有控制疫苗产品或性别。在对低 Ct 值（<25）样本进行测试时，我们在接种疫苗和未接种疫苗个体的标本中以相似的速率和相似的滴度检测到传染性病毒。这些数据表明，感染德尔塔变异株的接种疫苗个体能够释放具有传染性的 SARS-CoV-2，并且可能在传播 COVID-19 方面发挥作用。
