PertussisDespite the fact that infant deaths from pertussis have decreased 70 per cent in the last forty years, it remains the most frequent cause of death among the acute contagious diseases of early childhood: "The concentration of deaths in the first two years of life, especially under six months, is constant for all parts of the United States."193 A recent editorial194 points out that in Massachusetts from 1924 to 1943, 58 per cent of all deaths from this disease occurred in the first year of life, and 84 per cent in the first two years. Furthermore, the disease in . . .