The U.S. Food and Drug Administration has put on hold a trial of Novavax's COVID-influenza and its standalone flu vaccines after a participant who took the combination shot reported nerve damage, the company said on Wednesday.

Novavax said federal regulators put a clinical hold on its application for a combination Covid-19 and influenza vaccine and standalone flu inoculation, sending shares down sharply.

Novavax Inc.’s stock tumbled 16% early Wednesday after the company said the FDA has placed a clinical hold on its COVID-19-and-flu combination and stand-alone flu vaccine candidates, following a case of motor neuropathy in a participant in a mid-stage trial.