Vaxart soars on early-stage data of its new norovirus vaccine

Shares of drug developer Vaxart VXRT.O rise 81.2% to 71 cents premarket

Co says its new experimental norovirus vaccine produced significantly stronger immune responses than the original version in an early-stage trial

VXRT says that the second generation vaccine increased protective antibodies by 141% for one strain of norovirus and 94% for another

Co claimed that even at lower doses, the new vaccine performed better than VXRT's original version and all vaccines tested were well-tolerated with no serious side effects

As of last close, VXRT stock down 40.7% YTD