title: STUDIES ON THE HERD IMMUNITY OF SCHOOLCHILDREN AGAINST DIPHTHERIA.  3. BOOSTER FREQUENCY AND SCHICK RESPONSE.
mesh_terms: D000293:Adolescent; D002648:Child; D004165:Diphtheria; D004168:Diphtheria Toxoid; D006801:Humans; D032521:Immunity, Herd; D007114:Immunization; D013223:Statistics as Topic
chemical_list: D004168:Diphtheria Toxoid
keywords: ADOLESCENCE; CHILD; DIPHTHERIA TOXOID; STATISTICS