School-age children and adolescents suspected of having been to be infected with pertussis in Japan.

School-age children and adolescents suspected of having been to be infected with pertussis in Japan. Vaccine. 2018 Mar 30;: Authors: Yasui Y, Mitsui T, Nishimura T, Uchida K, Inokuchi M, Mori M, Tokumura M, Nakayama T Abstract Many countries including Japan have adapted acellular pertussis vaccines combined with diphtheria and tetanus toxoids (DTaP). DTaP vaccine coverage is approximately >90%, but pertussis re-emergence has been observed since 2000 in Japan. In the present study, anti-pertussis antibodies were investigated among school-age children and adolescents from 2013 to 2015. The positive rate of anti-pertussis toxin (PT) antibodies was higher among children aged 12-13 years (60.0%. 95%CI; 56.0-63.9%) in 2014 and 18-19 years (73.0%. 95%CI; 61.4-82.6%) in 2013, compared with 6-7 years (47.1%. 95%CI; 40.7-53.6%). The mean PT antibody titer was higher among children aged 12-13 years (23.8 EU/ml. 95%CI; 21.9-25.8) in 2014 and 18-19 years (29.3 EU/ml. 95%CI; 23.0-35.6) in 2013, compared with 6-7 years (18.3 EU/ml. 95%CI; 15.5-21.2). Distributions of pertussis antibodies and mean titers at their same grade of school-age were similar from 2013 to 2015. Although school-age children were immunized with 4 doses of DTaP, the data suggested the decay of vaccine-acquired immunity and possibility of asymptomatic infection in school age, indicating the additional DTaP vaccination before the entry of elementary school, p...
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research