Investigation of Variants In SARS-CoV-2 Infections after Three Doses of COVID-19 Vaccine

Abstract

Abstract Objective: Our study focused on retrospectively assessing variant of concern, specified by the World Health Organization (WHO), with one-step reverse transcription and real-time polymerase chain reaction (RT-PCR) test in SARS-CoV-2 positive patients after three doses of attenuated COVID-19 vaccine. Methods: 8.520 samples transported with viral nucleic acid buffer (vNAT) tubes between June 2021 and January 31, 2022, were tested and included in the study. All the patients whose samples were included in our research had 3 doses of CoronaVac (Sinovac Life Science Co, Ltd, Beijing, China). Gender distribution was 4686 (55%) female and 3834 ( 45%) males. Variant specific genome regions only found in B.1.351, P.1 and B.1.1.7 as well as ORF1ab and N gene regions are investigated by the Bio-Speedy® Emerging Plus kit (Bioeksen AR-GE Technologies, Turkey) used to identify the variants in the study. Results: All 8.520 samples were SARS-CoV-2 RT-PCR positive. Our study detected alpha and delta variants in 1460 (17.14%) and 3570 (41.9%) patients respectively. 2570 (30.16%) patients did not have any variants according to test results. It was observed that the spread of beta, gamma and other suspicious variants remained at relatively low rates. Conclusion: The delta variant became dominant from July until to the end of the year. Declining delta variant rates and increasing cases of suspected variants towards the beginning of December 2021 suggest the omicron variant. Therefore, molecular surveillance studies that are planned to take epidemiological data into consideration and to examine the prevalence and gene-based analysis of local and worldwide variants are required.