Hello, Given your grandson s history of tonsillectomy such recurrent fevers and infection are quite common. I will explain you why. Tonsils or adenoids are kind of first line defence against infection. They attack microbes and keep them off us. In some kids the reaction they cause is so intense that it interferes with their breathing. So, we remove them. After its removal this defence mechanism is lost and therefore they become prone to infection. I would advise you to follow preventive measures like wearing a face mask if he has sick contacts at school or home. Washing hands properly. If there are recurrent fevers it s also best to have a reevaluation with his pediatrician. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Manoj Pradeep