With school now well underway and the Delta variant raging, Covid-19 cases and hospitalizations are surging in children and raising alarm. In the United States, there's been a 240% increase in pediatric cases of the virus since July, the American Academy of Pediatrics said Monday, with reopening without proper masking a likely contributor, according to experts. Vaccines continue to play an integral part of this puzzle, with more children hospitalized and attending the emergency room in states with lower vaccination rates, according to the US Centers for Disease Control and Prevention (CDC). "This virus is really going for the people who are not vaccinated," Dr. Edith Bracho-Sanchez, associate professor of pediatrics at Columbia University Irving Medical Center, told CNN, adding: "And among those people are children who don't qualify for the vaccine and children and teens who qualify but are choosing not to get it." In the US, where kids as young as 12 have been able to access vaccinations since May, takeup appears to be plateauing around 40%, according to the latest CDC data. Meanwhile, a handful of countries have already begun to inoculate young children, with Cuba becoming the first country in the world to vaccinate toddlers as young as 2 in a bid to get kids safely back into the classrooms.