COVID-19 Waves with Associated Variants & Scenario in Pakistan

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enveloped RNA beta-coronavirus virus that is coronaviridae-related. It originated in Wuhan, China in December 2019 and is known to cause COVID-19 illness. SARS-CoV-2 posed a major threat to the world in concern of health along with trade and medical facilities. COVID-19 patients experience comorbid conditions like severe fever, typhoid, myocarditis, and a fatal black fungus attack. World Health Organization declared COVID-19 as an emergency on 30th January 2020 and a pandemic on 11th March. As of right now, COVID-19 has been verified to have infected over 100 million people across 210 nations, and 2 million of those infections have resulted in death. RT-qPCR (Reverse transcriptase qualitative PCR) test is performed if any symptoms exist, and isolation is necessary for three to five days after the confirmation. In Pakistan, it was reported firstly on 26th February 2020 by the Pakistan government when two persons were found infected with the disease. SARS-CoV-2 changes its genome constantly and results in the emergence of different variants in different waves. Pakistan has faced 6 sequential waves since 2020 to date, each associated with different variants and overlapping variants. The first wave was associated with B.1, B.1.471, B.1.36, second with B.1.36.31, B.1.247, B.1.1.1, B.1.160, B.1.471, B.1.562, B.1.1.7, B.1.1.250, B.1.261, B.1.351, P.1, third with B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.36, B.1.468, B.1.1.413, A.27, fourth with P.1, B.1.617.2, fifth with Omicron (B.1.1.529) and sixth with new subvariants of Omicron (BA.4 & BA.5). In terms of severity and infectivity, Omicron and its subvariants differ from Delta and other SARS-CoV-2 variants. In this review, we have discussed SARS-CoV-2 spike mutations, its variants along with their origin & association to wave(s), and its scenario in Pakistan.