Li Xi, Goodson James L, Perry Robert T
Accelerated Disease Control Branch, Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA.
Vaccines (Basel). 2024 Aug 22;12(8):937. doi: 10.3390/vaccines12080937.
Measles is a highly contagious disease and remains a major cause of child mortality worldwide. While measles vaccine is highly effective, high levels of population immunity are needed to prevent outbreaks. Simple but accurate tools are needed to estimate the profile of population measles immunity by age to identify and fill immunity gaps caused by low levels of vaccination coverage. The measles immunity profile estimates and visualizes the percentage of each birth cohort immune or susceptible to measles based on measles vaccination coverage. Several tools that employed this approach have been developed in the past, including informal unpublished versions. However, these tools used varying assumptions and produced inconsistent results. We updated the measles population immunity profile methodology to standardize and better document the assumptions and methods; provide timely estimates of measles population immunity; and facilitate prompt actions to close immunity gaps and prevent outbreaks. We recommend assuming that the second dose of the measles-containing vaccine (MCV2) and doses given during supplementary immunization activities (SIAs) first reach children who have been previously vaccinated against measles, so that previously unvaccinated children are reached only when the coverage of MCV2 or SIA is higher than the coverage achieved by all previous measles vaccination opportunities. This updated method provides a conservative estimate of immunization program impact to assess measles outbreak risk and to facilitate early planning of timely preventive SIAs to close population immunity gaps.
麻疹是一种高度传染性疾病，仍然是全球儿童死亡的主要原因。虽然麻疹疫苗非常有效，但需要高水平的人群免疫力来预防疫情爆发。需要简单而准确的工具来按年龄估计人群麻疹免疫状况，以识别和填补因疫苗接种覆盖率低而导致的免疫空白。麻疹免疫状况估计并直观显示每个出生队列中基于麻疹疫苗接种覆盖率的免疫或易感染麻疹的百分比。过去已经开发了几种采用这种方法的工具，包括非正式的未发表版本。然而，这些工具使用了不同的假设，产生了不一致的结果。我们更新了麻疹人群免疫状况方法，以规范并更好地记录假设和方法；及时估计麻疹人群免疫力；并促进迅速采取行动缩小免疫差距并预防疫情爆发。我们建议假设含麻疹疫苗的第二剂（MCV2）和补充免疫活动（SIAs）期间接种的疫苗首先接种给之前已接种过麻疹疫苗的儿童，这样只有当MCV2或SIA的覆盖率高于之前所有麻疹疫苗接种机会所达到的覆盖率时，才会接种给之前未接种过疫苗的儿童。这种更新后的方法提供了对免疫规划影响的保守估计，以评估麻疹疫情爆发风险，并促进及时规划预防性补充免疫活动以缩小人群免疫差距。
