CD40LG and measles: Between March 16 and April 4, 2015, both serum and throat swab samples were gathered from 102 suspected measles cases and then tested for measles virus IgM using IgM ELISA test kit (Zhuhai SEZ Haitai Biological Pharmaceuticals Co., Ltd., Zhuhai, China) and for measles virus RNA using a real-time reverse transcription PCR kit (Jiangsu BioPerfectus Technologies Co., Ltd., Jiangsu, China).