In our Article,¹ we presented findings from a case-control study that showed a protective effect of a meningococcal vaccine against gonorrhoea infection. In their Correspondence, Salaheddin Mahmud and Christiaan Righolt argue that the correct method to determine vaccine efficacy is a randomised controlled trial (RCT) and that our use of chlamydia as a control is problematic. We would like to clarify the points raised in their letter.

中文翻译：

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健康的疫苗作用的陷阱–作者的回复

在我们的文章^1中，我们介绍了一项病例对照研究的结果，该研究表明脑膜炎球菌疫苗对淋病的保护作用。Salaheddin Mahmud和Christiaan Righolt在他们的通讯中指出，确定疫苗效力的正确方法是随机对照试验（RCT），而我们使用衣原体作为对照是有问题的。我们想澄清他们在信中提出的要点。