Fappani Clara, Gori Maria, Canuti Marta, Terraneo Mara, Colzani Daniela, Tanzi Elisabetta, Amendola Antonella, Bianchi Silvia
Department of Health Sciences, Università degli Studi di Milano, 20146 Milan, Italy.
Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy.
Microorganisms. 2022 Aug 4;10(8):1567. doi: 10.3390/microorganisms10081567.
Measles is one of the most contagious diseases known to man. Despite the existence of a safe and effective live attenuated vaccine, measles can appear in vaccinated individuals. Paradoxically, breakthrough cases increase as vaccination coverage in the general population rises. In measles endemic areas, breakthrough cases represent less than 10% of total infections, while in areas with high vaccination coverage these are over 10% of the total. Two different vaccination failures have been described: primary vaccination failure, which consists in the complete absence of humoral response and occurs in around 5% of vaccinated individuals; and secondary vaccination failure is due to waning immunity or incomplete immunity and occurs in 2-10% of vaccinees. Vaccination failures are generally associated with lower viral loads and milder disease (modified measles) since vaccination limits the risk of complicated disease. Vaccination failure seems to occur between six and twenty-six years after the last vaccine dose administration. This review summarizes the literature about clinical, serological, epidemiological, and molecular characteristics of measles breakthrough cases and their contribution to virus transmission. In view of the measles elimination goal, the assessment of the potential decline in antibody protection and the targeted implementation of catch-up vaccination are essential.
麻疹是人类已知的传染性最强的疾病之一。尽管存在安全有效的减毒活疫苗，但接种过疫苗的个体仍可能出现麻疹。矛盾的是，随着普通人群疫苗接种覆盖率的提高，突破性病例会增加。在麻疹流行地区，突破性病例占总感染病例的比例不到10%，而在疫苗接种覆盖率高的地区，这一比例超过总病例的10%。已描述了两种不同的疫苗接种失败情况：原发性疫苗接种失败，即完全没有体液免疫反应，约5%的接种个体出现这种情况；继发性疫苗接种失败是由于免疫力下降或免疫不完全，2-10%的疫苗接种者会出现这种情况。疫苗接种失败通常与较低的病毒载量和较轻的疾病（非典型麻疹）相关，因为接种疫苗限制了出现复杂疾病的风险。疫苗接种失败似乎发生在最后一剂疫苗接种后的6至26年之间。本综述总结了关于麻疹突破性病例的临床、血清学、流行病学和分子特征及其对病毒传播的影响的文献。鉴于消除麻疹的目标，评估抗体保护作用的潜在下降并针对性地实施补种疫苗至关重要。
