The results of a Johns Hopkins-led study into the potential causes of increased transmission among certain SARS-CoV-2 variants has determined that at least two of these variants showed no evidence of higher viral loads but less likelihood of carriers presenting as asymptomatic.
Utilizing whole genome sequencing to identify the variants among a large cohort of samples, researchers from the Johns Hopkins School of Medicine investigated the Alpha variant, first detected in the U.K., and the Beta variant, first detected in South Africa. Both have demonstrated higher transmission capabilities. The results of the study leave the reason for that uncertain, however.
“The reason why these variants show higher transmissibility is not yet clear,” Adannaya Amadi, lead author of the study, said. “However, our findings did show that the patients infected with these variants are less likely to be asymptomatic compared to the control group. Although those infected with the variants were not at higher risk for death or intensive care admission, they were more likely to be hospitalized.”
Among samples, the U.K. variant represented 75 percent of the circulating viruses as of April 2021.
Additionally, the scientists compared 134 variant samples to 126 control samples and paired them with patients’ clinical information to simultaneously study genomics data and clinical disease/outcomes. Additional testing assessed viral load, accounting for the stage of the disease.
The study was funded by the Johns Hopkins Department of Pathology, Johns Hopkins University, the Maryland Department of Health, and the National Institutes of Health.