Emergence of SARS-CoV-2 variants of concern in the pediatric population of the United States (preprint)

The evolution of SARS-CoV2 virus has led to the emergence of variants of concern (VOC). Children, particularly <12 years old not yet eligible for vaccines, continue to be important reservoirs of SARS-CoV-2 yet VOC prevalence data in this population is lacking. We report data from a genomic surveillance program that includes 9 U.S. children's hospitals. Analysis of SARS-CoV-2 genome from 2119 patients <19 years old between 03/20 to 04/21 identified 252 VOCs and 560 VOC signature mutations, most from 10/20 onwards. From 02/21 to 04/21, B.1.1.7 prevalence increased from 3.85% to 72.22% corresponding with the decline of B.1.429/B.1.427 from 51.82% to 16.67% at one institution. 71.74% of the VOC signature mutations detected were in children <12 years old, including 33 cases of B.1.1.7 and 119 of B.1.429/B.1.427. There continues to be a need for ongoing genomic surveillance, particularly among young children who will be the last groups to be vaccinated.

Novel SARS-CoV-2 spike variant identified through viral genome sequencing of the pediatric Washington D.C. COVID-19 outbreak (preprint)

ABSTRACT The SARS-CoV-2 virus has emerged as a global pandemic, severely impacting everyday life. Significant resources have been dedicated towards profiling the viral genome in the adult population. We present an analysis of viral genomes acquired from pediatric patients presenting to Children’s National Hospital in Washington D.C, including 24 with primary SARS CoV2 infection and 3 with Multisystem Inflammatory Syndrome in Children (MIS-C) undergoing treatment at our facility. Viral genome analysis using next generation sequencing indicated that approximately 81% of the analyzed strains were of the GH clade, 7% of the cases belonged to the GR clade, and 12% of the cases belonged to S, V, or G clades. One sample, acquired from a neonatal patient, presented with the highest viral RNA load of all patients evaluated at our center. Viral sequencing of this sample identified a SARS-CoV-2 spike variant, S:N679S. Analysis of data deposited in the GISAID global database of viral sequences shows the S:N679S variant is present in eight other sequenced samples within the US mid-Atlantic region. The similarity of the regional sequences suggests transmission and persistence of the SARS-CoV-2 variant within the Capitol region, raising the importance of increasing the frequency of SARS-CoV-2 genomic surveillance. IMPORTANCE A variant in the SARS-CoV-2 spike protein was identified in a febrile neonate who was hospitalized with COVID-19. This patient exhibited the highest viral RNA load of any COVID-19 patient tested at our center. Viral sequencing identified a spike protein variant, S:N679S, which is proximal to the cleavage site at residue 681. The SARS-CoV-2 surface spike is a protein trimer (three subunits) which serves as the key target for antibody therapies and vaccine development. Study of viral sequences from the GISAID database revealed eight related sequences from the US mid-Atlantic region. The identification of this variant in a very young patient, its critical location in the spike polyprotein, and the evidence that it has been detected in other patients in our region underscores the need for increased viral sequencing to monitor variant prevalence and emergence, which may have a direct impact on recommended public health measures and vaccination strategies.

The Use of Saliva as a Diagnostic Specimen for SARS CoV-2 Molecular Diagnostic Testing for Pediatric Patients (preprint)

Background Children are an important population to test for COVID-19 infection, particularly because they may shed the virus without displaying symptoms. Testing children for COVID-19 via sensitive molecular methods is important, although collecting nasopharyngeal (NP) specimens can be challenging. A less invasive mode of specimen collection that yields test results comparable to those from NP specimens would be beneficial to simplify sample collection. Methods To demonstrate that saliva is a suitable specimen for collection from children, the clinical usability/acceptability and the analytic performance of saliva were compared to NP specimens suspended in viral transport medium. Four different FDA EUA-approved real-time RT-PCR assays and one EUA approved saliva collection device were investigated. Results The study population included 526 patients between the ages of 3 and 61 years, 461 (88%) were <18 years, 425 were asymptomatic (81.1%), 92 were symptomatic (17.6%). Saliva mixed with saliva stabilizing buffer was found to yield comparable sensitivity to NP specimens when tested on the AllPlex SARS-CoV-2 molecular test (Seegene Inc). The analytic sensitivity of the AllPlex assay during testing of spiked saliva mixed with SpectrumDNA saliva stabilizer was found to be 250 genomic copies/mL. Conclusions Of the four FDA EUA-approved SARS-CoV-2 PCR assays studied, we found the AllPlex assay to be best suited for testing saliva specimens collected from children 5 years of age or older. The sensitivity of viral detection was equivalent to NP specimens when saliva specimens were mixed with the saliva stabilizer.