Considering that China is charged 100,000,000,000,000USD to compensate for economic loss caused by pandemic, US$493.6 lent by China won't be a problem.
But, I think that a country where the original outbreak happened won't be responsible for pandemic.
First, when many people in Wuhan were reported to be infected, no patient was confirmed in Europe. It means Europe had time to prepare for protecting people from COVID-19. So, explosive increase of patients in Europe was caused by lack of preparation in Europe.
Second, European people forget the fact that they've also brought virus into native Americans in the Age of Discovery. Since they didn't have antibodies against the virus, some tribes were exterminated. If they tries to do the same thing against European people, can they accept the lawsuit?