(WHTM) — The director of the CDC is warning that the Delta variant could soon become the dominant COVID strain in the United States.

The variant was first found in India. It transmitted more easily than some of the variants that have been seen and could put more unvaccinated people in the hospital. Another concern is who the variant is hitting hardest — younger people.

“We’re seeing in the United Kingdom it is showing up in younger individuals, especially in school-aged kids who have not been vaccinated or younger adults who are less likely to be vaccinated,” Mohammad Ali, infectious disease physician at Penn State Health Holy Spirit Medical Center.

Experts continue to stress that the best defense against this variant and COVID, in general, is to get vaccinated. It’s not clear when a vaccine will be authorized for children under the age of 12.