Emerging SARS-CoV-2 Variants in Uganda in the Era of COVID-19 Vaccination

The emergence of SARS-CoV-2 variants has heightened concerns about vaccine efficacy, posing challenges in controlling the spread of COVID-19. As part of the COVID-19 Vaccine Effectiveness and Variants (COVVAR) study in Uganda, this study aimed to genotype and characterize SARS-CoV-2 variants in patients with COVID-19-like symptoms who tested positive on a real-time PCR. Amplicon deep sequencing was performed on 163 oropharyngeal/nasopharyngeal swabs collected from symptomatic patients. Genome assembly, lineage classification and phylogenetic analysis was performed using the Edge Bioinformatics pipeline version 2.4.0, Pangolin version 4.3.1 and iqtree version 2.3.6 software respectively. Of the 163 deep sequences analyzed between April 2023 and March 2024, the most common were XBB.1 lineages and sublineages (113, 69.3%), followed by JN.1* (12, 7.4%), XBB.2* (11, 6.7%) and FL* (11, 6.7%), EG* (7, 4.3%), others (BQ.1.1, FY.4.1, FY.4.1.2, GY.2.1, HK.27.1) (5, 3.1%) and CM* (4, 2.5%). XBB.1* dominated from April to July 2023; thereafter, other variants, including JN.1* were increasingly detected. There was no statistically significant association between vaccine status and lineage assignment (Fisher's exact test, p-value = 0.994). Our findings showed that the Omicron variant, specifically the XBB.1* lineage, was the dominant circulating virus. However, the emergence of the JN.1 variant that exhibits a significant spike protein mutation profile could impact COVID-19 transmission in Uganda.