The FDA and CDC have approved vaccines for the last remaining demographic in the U.S.: children under the age of five. Doctors say the move is important for immunity in this age group as well as broader herd immunity. But some parents may be unsure of what vaccine their child will get and what the dosage might be. Dr. Rajeev Fernando, expert in Disaster Medicine at Harvard Medical School and global infectious diseases doctor joins Closing Bell to explain what parents should know about vaccines for kids under five, why vaccines for this age group are important, and more.