20年来的实践证明,口服脊髓灰质炎活疫苗效果极好且非常安全。那些坚持给大多数易感儿童口服脊髓灰质炎疫苗的国家,麻痹型脊髓灰质炎差不多已被消灭。一旦这种严重的疾病得到了控制,并对国计民生已不再构成威胁的情况下,人们开始关心疫苗的付作用来虽然 Twenty years of practice have shown that oral poliovaccine is extremely effective and safe. Countries that insist on oral polio vaccination for the most vulnerable children have almost eradicated paralytic poliomyelitis. Once this serious disease has been brought under control and no longer a threat to national economy and the people’s livelihood, people are beginning to pay attention to the role of vaccines. Although