Experts say the Delta variant poses a greater chance of infection for unvaccinated people if they are exposed to this version of the virus. The variant, first identified in India, may be twice as transmissible as the conventional coronavirus strains. The Delta variant has been responsible for the rise in cases recently in India, the United Kingdom and elsewhere. But vaccinated people are well protected against infection and illness from the Delta variant. One recent study found that the full course of the Pfizer-BioNTech vaccine (two doses) was 88% effective against symptomatic disease caused by the Delta variant and 96% protective against hospitalization.