二次混合 meaning in English

secondary mixing

All children below the age of 6 can receive a mmr vaccine at the maternal and child health centres . the second dose is provided by the mobile inoculation teams of the department of health to students at schools to enhance their immunity against the disease . the following people should consult a doctor before receiving the vaccination
六岁以下的小童可往卫生署辖下的各母婴健康院接受麻疹、流行性腮腺炎及德国麻疹混合疫苗注射，学童则可在校方安排下，于学校接受由卫生署派出的流动注射队提供的第二次混合疫苗注射，加强其免疫能力。