Ramsay Mary E, McVernon Jodie, Andrews Nick J, Heath Paul T, Slack Mary P
Immunisation Division, Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre, London, United Kingdom.
J Infect Dis. 2003 Aug 15;188(4):481-5. doi: 10.1086/376997. Epub 2003 Jul 31.
In October 1992, Haemophilus influenzae type b (Hib) conjugate vaccine was introduced to infants in the United Kingdom with a "catch-up" program for those aged <4 years. Initially, the rate of invasive Hib disease decreased dramatically but has been increasing since 1999. To determine possible reasons for this increase, the effectiveness of Hib conjugate vaccine was estimated by use of the screening method. Between October 1993 and December 2001, a total of 443 cases of Hib infection occurred in children eligible for vaccination; 363 (82%) were fully vaccinated. Vaccine effectiveness was estimated to be 56.7% (95% confidence interval, 42.5-67.4). Effectiveness was lower in children vaccinated during infancy, compared with those who were vaccinated during the catch-up campaign (P=.0033), declined with time since vaccination (P=.0008), and was lower in children born during 2000-2002, compared with other children scheduled for infant vaccination (P=.0041). Use of a catch-up vaccination program enhanced the control of Hib infection in England and Wales. Since 1999, however, low effectiveness in infants, declining effectiveness with age, and the use of lower-efficacy vaccines have contributed to increased rates of Hib infection. The potential role of boosters needs to be considered.
1992年10月，b型流感嗜血杆菌（Hib）结合疫苗在英国被引入婴儿群体，并为4岁以下儿童实施了“补种”计划。起初，侵袭性Hib疾病的发病率大幅下降，但自1999年以来一直在上升。为了确定这种上升的可能原因，采用筛查方法评估了Hib结合疫苗的有效性。在1993年10月至2001年12月期间，共有443例符合疫苗接种条件的儿童发生了Hib感染；其中363例（82%）已全程接种疫苗。疫苗有效性估计为56.7%（95%置信区间，42.5 - 67.4）。与在补种活动期间接种疫苗的儿童相比，婴儿期接种疫苗的儿童有效性较低（P = 0.0033），随着接种疫苗后的时间推移而下降（P = 0.0008），并且与其他计划进行婴儿期接种的儿童相比，2000 - 2002年出生的儿童有效性较低（P = 0.0041）。补种疫苗计划的实施加强了英格兰和威尔士对Hib感染的控制。然而，自1999年以来，婴儿中疫苗有效性较低、有效性随年龄下降以及使用效力较低的疫苗导致了Hib感染率上升。需要考虑加强免疫的潜在作用。
