Mostly, it is viral infection parainfluenza type I and II, affecting children between 6 months to 3 years of age.

大数是 I 型和 II 型副流感导致的病毒感，于 6 个月到 3 岁的儿童。

Covid-19 vaccine maker Moderna just finished an early study of an mRNA vaccine against HMPV and parainfluenza, according to the website clinicaltrials.gov.

据 clinicaltrials.gov 网站报道，新冠病毒疫苗 Moderna 刚刚完成了一种针对HMPV和副流感病毒的 mRNA 疫苗的早期研究。

These viruses are the same ones that cause the common cold like rhinovirus, coronavirus, influenza virus, respiratory syncytial virus- or RSV for short, and parainfluenza virus.

这些致病病毒与导致普通感冒的病毒相同，如鼻病毒、冠状病毒、流感病毒、呼吸道合胞病毒（简称RSV）以及副流感病毒。