Broome C V, Preblud S R, Bruner B, McGowan J E, Hayes P S, Harris P P, Elsea W, Fraser D W
J Pediatr. 1981 Mar;98(3):362-7. doi: 10.1016/s0022-3476(81)80696-8.
In the period April to October, 1977, an epidemic of pertussis in the outpatient population of a large metropolitan hospital involved 115 cases that were diagnosed by culture or direct fluorescent antibody tests. A study of secondary cases in household contacts showed attack rates of 81% in children under one year of age; attack rates decreased with increasing age to 8% in persons over 20 years of age. Vaccine efficacy was estimated to be 63%. There was no evidence of decreased efficacy with increasing time after vaccination. Fourteen asymptomatic FA-positive individuals were identified; four of these were also culture positive. Four were adults and ten were children. Nine of the ten children had received three or more vaccinations, compared to only 29 of 78 symptomatic children (P = 0.002).
1977年4月至10月期间，一家大型都市医院门诊人群中发生了百日咳疫情，115例病例通过培养或直接荧光抗体检测确诊。对家庭接触者中的二代病例研究显示，1岁以下儿童的发病率为81%；发病率随年龄增长而下降，20岁以上人群的发病率为8%。疫苗效力估计为63%。没有证据表明接种疫苗后随着时间推移效力会降低。确定了14名无症状的荧光抗体检测阳性个体；其中4名培养结果也呈阳性。4名是成年人，10名是儿童。10名儿童中有9名接种了三次或更多次疫苗，而78名有症状儿童中只有29名接种了三次或更多次疫苗（P = 0.002）。
