Laboratory tests on the effectiveness of oral vaccination of young children against typhoid and paratyphoid A and B

Abstract In Romania, pre-school children are excluded from subcutaneous inoculation with typhoid and paratyphoid A and B vaccine. The authors have therefore investigated the possibility of giving them an oral vaccine. Laboratory tests were carried out on 30 children from 3 to 7 years of age. Samples of blood serum were collected before and after vaccination and subsequently tested for (1) seroprotection in chick embryos, (2) seroprotection in white mice, (3) titration of the agglutinating antibodies, and (4) electrophoretic pattern. The results obtained showed that the oral administration of the vaccine can, under the conditions used in the test, afford a considerable degree of protection to young children.