Chickenpox is very contagious. You are more likely to catch chickenpox if you aren’t immune and are available into contact with an infected person. You could be immune should you:急性脳炎（ウエストナイル脳炎、西部ウマ脳炎、ダニ媒介脳炎、東部ウマ脳炎、日本脳炎、ベネズエラウマ脳炎及びリフトバレー熱を除く）Spots within the mouth immediately rupture