Recent research (J. Food Protection, 67(2004)1743-1750) has shown that Norovirus and Hepatitis A virus survive during marinating for at least 4 weeks. During these 4 weeks only 10% reduction of the virus concentration was observed.
The pH during marinating was 3,75 and contained vinegar, sugar and herbs comparable to normal recipes for marinating.
Heating the marinated mussels (37 seconds in boiling water, plus steaming for 3 minutes) also hardly affected the virus concentrations.
It is thus clear that viruses survive in marinated mussels.