Increasingly defensive about accusations that drugs and vaccines are inadequately tested for safety, in recent years safety-obsessed regulators have required massive, hugely expensive, and time-consuming clinical trials designed to detect even very rare side effects. Consider, for example, that before its US approval, a vaccine against rotavirus (a common, sometimes fatal gastrointestinal infection in children) was tested in more than 72,000 children – and another 40,000-plus in post-marketing studies.
为了免于受到药物和疫苗安全测试不足的指控，最近几年来，监管者过度重视安全性，开始要求大规模、高成本、长时间的临床试验，以检验可能是非常罕见的副作用。比如，某种轮状病毒（一种可能令幼儿致死的常见肠胃病）疫苗在得到美国的批准之前先在72 000名幼儿身上进行了试用，后来有进行了40 000例上市后研究。