key: cord-0698744-yo8z0lw4 authors: Yılmaz Çelebi, Miray; Kıymet, Elif; Böncüoğlu, Elif; Şahinkaya, Şahika; Cem, Ela; Düzgöl, Mine; Akaslan Kara, Aybüke; Ayhan, Fahri Y.; Bayram, Süleyman N.; Devrim, İlker title: Evaluation of childhood hospitalization rates and degree of severity of SARS‐CoV‐2 variants, including B.1.1.7 (Alpha), B.1.315/P.1 (Beta/Gamma), and B.1.617.2 (Delta) date: 2022-01-23 journal: J Med Virol DOI: 10.1002/jmv.27587 sha: dae8c799be04be48fbcc047df741c5ab36ec086b doc_id: 698744 cord_uid: yo8z0lw4 Severe acute respiratory syndrome coronavirus 2 is reappearing with an increasing number of variants every day; this study aimed to determine the effect of B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), and B.1.617.2 (Delta) variants on hospitalization rates. This single‐center study was conducted at the University of Health Sciences Dr. Behçet Uz Children's Hospital from March 11 to August 27, 2021. Variant analyses of symptomatic patients admitted to the hospital who were found to be positive for COVID 19 PCR was performed. Out of 680 cases, 329 (48.4%) were B.1.1.7 variant, 17 (2.5%) were B.1.351/P.1 variant, and 165 (24.2%) were B.1.617.2 variant. One hundred and sixty‐nine (24.9%) case variant analysis results were negative. The hospitalization rate of patients with the B.1.617.2 variant was 19.4%, the B.1.351/P.1 variant was 18%, the B.1.1.7 variant was 9.4%, and the negative variant was 10.1%. The B.1.617.2 (Delta) variant, which has become widespread all over the world recently, increases the rate of hospitalization in children. In SARS-CoV-2, which is an RNA virus, mutations occur naturally as the virus reproduces. So far, thousands of mutations have emerged, but only a very small fraction are likely to matter and alter the virus in a significant way. The first mutation in the United Kingdom was detected in September 2020, and with the rapid increase of cases, in December 2020, it was named VUI-202012/01 (the first "Variant Under Study" in December 2020) and was identified with a set of 17 changes or mutations. One of the most important of these mutations has been identified as an N501Y mutation in the spike protein that the virus uses to bind to the human ACE2 receptor. Changes in this part of the spike protein are thought to increase the contagiousness of the virus. 3 A p ≤ 0.05 was considered statistically significant. There was an additional underlying disease in 24 patients, and all of these patients were in the hospitalized group, and the ratio of ÇELEBI ET AL. | 2051 underlying disease was significantly higher in the hospitalized patients compared to outpatient groups (p < 0.001). The underlying diseases were as follows: Down syndrome in 2 patients, neurological diseases such as epilepsy and cerebral palsy in 10 patients, haematooncological malignancies in 7 patients, immunodeficiency in two patients and laryngomalacia, nephrotic syndrome, prematurity with operated patent ductus arteriosus were detected in one patient each. Considering the effect of age on hospitalization rate, the mean age of outpatients was 9 years and 8 months (minimum 1 month to maximum 17 years), and the mean age of hospitalized patients was 5 years and 10 months (minimum 15 days, maximum 17 years), and significantly higher in the outpatient group (p < 0.001). Table 1 ). In this study, following the literature, the variant type with the highest hospitalization rate was Delta. The second most frequent hospitalization after the Delta variant was in the Beta/Gamma variant. The SARS-CoV-2 spike protein receptor-binding domain is the critical determinant of viral tropism and infectivity. 10 Studies show that SARS-CoV-2 can mutate spike proteins to evade antibodies and that these mutations are already present in some virus mutants. 11 SARS-CoV-2 was shown to be capable of mutations and studies showed that it has undergone thousands of mutations since its emergence, and these resulting variants have been classified as a variant of interest (VOI), variant of concern (VOC), and variant under monitoring (VUM). Four variants, which were determined as VOC and started to spread from four different countries, gained importance and came to the fore due to the speed of spread. Of these mutations, hospitalization rates compared to non-VOC cases. 15 In a retrospective study, the probability between infection with the B.1.617.2 variant and the possibility of developing pneumonia or severe COVID-19 was found to be higher than Alpha and Beta variants. 16 In a study conducted in Scotland, Delta VOC was found mainly in younger groups. Compared with Alpha VOC, the risk of COVID-19 hospitalization was approximately doubled in those with Delta VOC, particularly those with five or more related comorbidities, with an increased risk of admission. 17 In our study, no significant difference was found in terms of hospitalization rates when the B.1.1.7 variant and those without variants were compared. However, as determined in other studies, when the hospitalization rate was evaluated in our study, the B.1.617.2 variant was found to be approximately two times higher than the other variant types, and it was found statistically significant. 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SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospital admission, and vaccine effectiveness Clinical characteristics and outcomes of COVID-19 in children in Northern Iran Clinical manifestations and outcomes of critically ill children and adolescents with coronavirus disease contributed essential intellectual content. Dr. Fahri Y. Ayhan designed the data collection instruments. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. The data that support the findings of this study are available from the corresponding author upon reasonable request.