But the virus has yet to show itself to be more severe than seasonal flu.

VOA: special.2009.08.18

You might have that commonly, but even more severe than normal; aches; and a rash.

你们都有过这种经历,有时也许比平常的更加严重,疼痛,皮疹

耶鲁公开课 - 生物医学工程探索课程节选

But medical help is necessary if the condition is more severe.

VOA: special.2010.07.27

but still they sat and talked. The ringing became more severe.

VOA: special.2009.05.16

But patients with more severe forms can go blind.

VOA: special.2010.07.12