The longer that unproven therapies stay on the market, the greater is the risk that a history of use can be framed as evidence of safety and efficacy.

未经检验的干细胞疗法在市场上停留的时间越长，那些使用历史被做为其安全性和有效性的证明的风险就越大。

youdao

An interim landmark would be to develop and license a first-generation vaccine by 2015 with 50% protective efficacy against severe disease and death that would last longer than one year.

一项暂定目标是到2015年之前将研制和许可使用第一代具有一年以上50%预防功效的疫苗，可预防严重疾病和死亡。

youdao

Larger and longer trials are needed to evaluate the clinical efficacy and safety of this approach.

但还需要更加大规模和更长期的实验研究来评估这种方法的临床疗效和安全性。

youdao

In 2004 the efficacy and profitability of Internet advertising was no longer arguable.

FORBES: Net--One, TV--Zero

In addition, the experimental insomnia drug Suvorexant exhibited strong efficacy in phase III clinical trials as the drug helped insomnia patients fall asleep faster and stay asleep longer versus a placebo.

FORBES: Merck Revised To $50 On Strong Pipeline