The Prevalence of Protein S Variant in Patients Diagnosed with COVID-19

The rapid spread of the new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) which causes the coronavirus disease 2019 (COVID-19) facilitated the emergence of numerous variants. The present study aimed to investigate the prevalence and change of important "S" protein variants such as N501Y, DelH69/ 70, and E484K in SARS CoV-2 PCR positive patients diagnosed with COVID-19 who have referred to a private hospital within the period that mutations were detected during COVID-19 pandemic.

One hundred and eighty-seven patients who have been referred due to the suspicion of COVID-19 between December 2020 and April 2021 and in whom SARS-CoV-2 was detected positive in the PCR test were enrolled into the study. These patients were randomly selected among 285 patients detected in these months, among those with the most accurate graphics and data. The RNA material extracted from the nasopharyngeal swab samples taken from the patients was analyzed and specifically N501Y, del69-70, and E484K mutations were investigated through the Real-Time PCR method.

The mean age of the patients was 37.5 ± 14.1 years. Mutations were detected in 84 (44.9%) samples in total (N501Y + DelH69/70 by 81%, DelH69/70 by 7.1%, E484K by 7.1% and N501Y + E484K by 4.8%). There was no sample detected with the N501Y mutation. The mutation rate between December - February was detected between 1% and 8%, and the mutation rate increased to 39% to 44% in April and March. While DelH69/70 mutation was detected in December 2020 only, it was observed that N501Y + DelH69/70 variants became dominant as of February 2021, and E484K and N501Y + E484K variants started to appear in March and April. It was observed that the variant rates included DelH69/70 (p < 0.001), N501Y (p < 0.001), N501Y + DelH69/70 (p < 0.001), and N501Y + E484K (p = 0.01) mutations increased significantly according to the months. The E484K mu-tation was significantly higher in males (p = 0.037). There was no differences between mutation rates between the age groups.

Our findings indicate that the appearance of important SARS-CoV-2 variants gradually increases, that rates of mutation increase up to 40% within several months, that the N501Y + DelH69/70 variant gradually becomes to be dominant, and that different variations appear along with mutations.