Influenza viruses are grown in eggs to produce inactivated vaccines, but these viruses typically contain mutations in the genes coding for haemagglutinin, which might reduce vaccine effectiveness. A new study published in the New England Journal of Medicine has shown that a recombinant, quadrivalent influenza vaccine provided better protection against influenza-like illness than a standard-dose, egg-grown, inactivated influenza vaccine in adults aged 50 years or older.

中文翻译：

---

50岁或以上成年人的重组流感疫苗

流感病毒在卵中生长以生产灭活疫苗，但这些病毒通常在编码血凝素的基因中含有突变，这可能会降低疫苗的有效性。在《新英格兰医学杂志》上发表的一项新研究表明，对于50岁以上的成年人，重组的四价流感疫苗比标准剂量，鸡蛋生长的灭活流感疫苗能更好地预防类似流感的疾病。