At 3 days post-infection, wild-type virus and both mutant viruses replicated in the nasal turbinates to a similar level, whereas the virus titers in the lungs of hamsters infected with Nsp5-L50F/E166V or Nsp5-L50F/E166A/L167F were significantly lower than those of wild-type virus (Fig. 3c). This evidence concerns the gene SPECC1 and infection.