The vaccine summit builds on a commitment last year by nearly 200 countries to eradicate polio, develop new and improved vaccines at affordable prices, and deliver them to every child by 2020.
疫苗峰会基于去年近200个国家所提出的在2020年前消灭小儿麻痹症，开发和改进可负担疫苗并交到每位儿童手中的承诺。