Cuba has begun a massive vaccination campaign for children between the ages of two and 10, becoming one of the first nations to do so.

Health officials say Cuba’s homegrown vaccines have been found safe to give to young children.

“Our country would not put [infants] even at a minimal risk if the vaccines were not proven safe and highly effective when put into children,” Aurolis Otaño, director of the Vedado Polyclinic University, told The Associated Press in a vaccination room.

Otaño said the circulation of the Delta variant produced an increase in infections among the youngest, so Cuba’s scientific community decided to “take the vaccine to clinical trial” and it was approved for children.

The Polyclinic expects to vaccinate about 300 children between two and five. Those between five and 10 are receiving their first shot at their schools.

Read the full AP story here.