 [ Symptoms ] if a child has had polio vaccine at 2mths 4mths and 6mths would getting ipv at 18 mths harm the child  the child also recieved ditheria and pertusis shots at the same time are there any side effects from getiing the 4th shot prior to her 4th birthday [ Disease ] no harm but he will still need a polio booster between the ages of 4 6