Genomic diversity of SARS-CoV-2 in Pakistan during fourth wave of pandemic

ABSTRACT

The emergence of different variants of concern of SARS-CoV-2 has resulted in upsurges of COVID positive cases around the globe. Pakistan is also experiencing fourth wave of COVID-19 with increasing number of positive cases. In order to understand the genomic diversity of circulating SARS-CoV-2 strains during fourth wave of pandemic in Pakistan, the current study was designed. The samples from 89 COVID-19 positive patients were subjected to whole genome sequencing using GeneStudio S5. The results showed that 99% (n=88) of isolates belonged to delta variant and only one isolate belonged to alpha variant. Among delta variant cases 26.1% (n=23) isolates were showing B.1.617.2 while 74% of isolates showing AY.4 lineage. Islamabad was found to be the most affected city with 54% (n=48) of cases, followed by Karachi (28%, n=25), and Rawalpindi (10%, n=9). AY.4 has slight difference in mutation profile compared to B.1.617.2. E156del, G142D and V26I mutations in spike and T181I in NSP6 were present in B.1.617.2 but not in AY.4. Interestingly, A446V mutation in NSP4 has been only observed in AY.4. The current study highlights the circulation of primarily delta variant (B.1.617.2 and AY.4) during fourth wave of pandemic in Pakistan.