Nathanson N
Rev Infect Dis. 1982 Sep-Oct;4(5):940-50. doi: 10.1093/clinids/4.5.940.
Mass immunization with oral poliovirus vaccine (OPV) was begun in the United States in 1963, and the least natural outbreak of poliomyelitis occurred in 1972. Since immunization programs fail to reach the total population, eradication has been achieved in the presence of a residual susceptible population of at least 5% (2-5 million children under the age of 15 years). It is proposed that the fade-out of wild polioviruses is explained by their disappearance during the winter, a low point in the yearly cycle of the virus. In the post-eradication era, the continued presence of millions of susceptible children and adults presents a constant potential hazard. Every effort should be made to maintain maximal levels of immunization with oral poliovirus vaccine and to prevent the reintroduction of wild polioviruses into the United States.
1963年美国开始大规模口服脊髓灰质炎疫苗（OPV）免疫接种，1972年出现了最少的自然脊髓灰质炎疫情。由于免疫规划未能覆盖全体人口，因此在至少5%（200 - 500万15岁以下儿童）的残余易感人群存在的情况下仍实现了根除。有人提出，野生脊髓灰质炎病毒的消失是因为它们在冬季（病毒年度周期的低点）消失。在根除后的时代，数百万易感儿童和成人的持续存在构成了持续的潜在风险。应尽一切努力维持口服脊髓灰质炎疫苗的最高免疫接种水平，并防止野生脊髓灰质炎病毒重新传入美国。
