purified meningococcal vaccine

例句：

1. 1. The purification process for this vaccine is crucial to its effectiveness.
   这种疫苗的净化过程对其有效性至关重要。
2. 2. The meningococcal vaccine has been shown to be highly effective in preventing meningitis.
   研究表明，这种脑膜炎球菌疫苗在预防脑膜炎方面非常有效。
3. 3.The purification of the vaccine is a key step in ensuring its safety and efficacy.
   确保疫苗安全和有效的关键环节之一是其净化过程。