美洲在2016年消除麻疹曾是惊人的成就，但这一成果很快破裂：2017年委内瑞拉暴发，随后传播到巴西，并在新冠来临前已至少感染3万人、造成100多人死亡，成为美洲22年来最严重时期。

当前疫情可能更糟：截至2026年4月25日，泛美卫生组织已记录18,352例确诊病例，而去年为14,503例，迄今至少45人死亡，病例主要集中在墨西哥和危地马拉。墨西哥疫苗覆盖率从2014年第二剂的96%跌至2024年不足70%，拉美整体也由全球最高之一滑向最低之一。

墨西哥自2025年1月至2026年3月已紧急接种约3,000万剂，但危地马拉仍在上升，已感染5,399人、至少4名儿童死亡；与此同时，2026年6月世界杯预计将吸引约550万名球迷，增加传播风险。造成反弹的原因包括新冠削弱卫生服务、政府削减预算、以及疫苗犹豫上升；目前PAHO覆盖的35个国家中只有19个拥有某种电子免疫登记。

The Americas’ elimination of measles in 2016 was spectacular, but it did not last long: an outbreak in Venezuela in 2017 spread to Brazil, and before covid arrived it had infected at least 30,000 people and killed more than 100, making it the worst period in the Americas for 22 years.

The current outbreak is set to be worse, with PAHO recording 18,352 confirmed cases by April 25th 2026, up from 14,503 last year, and at least 45 deaths so far, mostly children. Mexico and Guatemala account for most cases, while Bolivia and Peru have also been reached.

Mexico launched an emergency campaign and delivered about 30m doses between January 2025 and March 2026, but Guatemala is still rising with 5,399 infections and at least four child deaths. The broader trend is worrying: Mexico’s second-dose coverage fell from 96% in 2014 to under 70% in 2024, and only 19 of the 35 PAHO countries now have an electronic immunisation registry.

Source: Why measles is returning to the Americas

Subtitle: Falling vaccination coverage is letting a deadly virus back in

Dateline: 5月 14, 2026 11:24 上午 | New York