Study of the Pertussis Antibody (Anti PT, Anti F-HA Antibody) in Children and Pregnants

Abstract

Since autumn in 1981, the new pertussis component vaccine has been used. Component means pertussis toxin (PT) and filamentous hemagglutinin (F-HA), and the method for measurement of these new antibodies have been made. Then we studied for anti PT and anti F-HA antibody. The subjects are 57 children with DPT vaccination, 28 children without DPT vaccination, 7 children contracted with pertussis and 300 pregnants. We conformed the micro ELISA method by Sato, National Institute of Health. For the effective antibody titer, we set over 10 ELISA UNIT (EU) in both antibodies according to the recent reports. Result In DPT vaccinated children, both anti PT and anti F-HA antibody were tendency to decrease as years after vaccination. In 7 out of 20 cases (35%) over 10 years after vaccination, both levels showed below 10 EU, it's seemed that they have probability of suffering from whooping cough. And in cases of less 5 years after vaccination, the positive rate of anti F-HA antibody showed higher than anti PT antibody. Out of 28 children without DPT vaccination, anti PT antibody in 2 cases (7.1%) and anti F-HA antibody in 3 cases (10.7%) showed below 10 EU. Non of them had neither anti PT nor anti F-HA antibody titer more than 10 EU. It means 5 cases of them (17.8%) have the antibody titer of protecting infection. It is suggested that subclinical infection exists in them. In 7 children contracted pertussis, anti PT antibody showed 10 EU or more in all of them, but anti F-HA antibody showed 10 EU or more in only 2 cases. In 26 cases out of 300 pregnants, both anti PT and anti F-HA antibody showed below 10 EU. It is known that both anti PT and anti F-HA antibody transfer to fetus through placenta, then they and their newborns have probability of suffering from whooping cough. So it's in need of reference the mother without these antibodies, for protection of pertussis infection in newborns.