Sorry but DMND is the only solid that's immune to virus; all other elements immune to virus are SOAP, AMTR, PLSM, and energy particles; SING is said to be immune to virus in the tpt wiki, but it isn't; they should really make SING immune to virus.

No, CONV with a ctype and a layer above it is also immume to VIRS. Two other mechanisms to make VIRS immune things are by using DRAY and CRAY to make it so that anything the VIRS erases is replaced quick enough it doesn't matter, preferable using subframe things. Also, it might not seem very useful, but VIRS is immune to VIRS. If you give some VRSS a really high tmp3, it will not infect anything for as many frames as you set it to (I can't remember the highest that is save-able), but it will prevent any VIRS it touches from infecting anything for the same time. Just keep in mind, if you go that route, you have to give the VRSS a tmp4 of 0, or it will despawn.

I just found out that you can make undying virus that doesn't infect by setting it's tmp3 to -1 and it's tmp4 to 0.