Answer:
The Delta variant might cause more severe illness than previous strains in unvaccinated persons. In two different studies from Canada and Scotland, patients infected with the Delta variant were more likely to be hospitalized than patients infected with Alpha or the original virus strains. Although vaccine effectiveness has waned slightly against infection with Delta, data so far suggests the Moderna vaccine is approximately 50 to 95 percent effective against Delta, and the Pfizer-BioNTech vaccine is 39 to 96 percent effective against Delta.