The Delta variant of COVID-19, first identified in India, has been classified as a "variant of concern" by the CDC due to its increased transmissibility and potential severity. It is estimated to be 60% more infectious than the Alpha variant and has rapidly spread, accounting for a significant percentage of cases in several U.S. states and dominating infections in countries like the U.K. Vaccines remain effective against the Delta variant, with recent data showing about 88% effectiveness for the Pfizer vaccine after two doses. Health officials emphasize the importance of vaccination, particularly among younger populations, to curb the spread of this variant. The urgency to get vaccinated is underscored by rising case numbers and the potential for Delta to alter the trajectory of the pandemic.