Come to think of it the only time shown that type really meant anything was in:
A) DW1 where you had have a virus type partner to get into Grey Lord's Manor or a Vaccine to get into the Ice Sanctuary.
B) In Adventure where the cards had to be placed just right to allow the children to open the gate to get home.
Or
C) The effect of DNA Digivolution early in DW2.
Other than that I think the type didn't amount to much in day to day life.
Then again Ogremon made a vaguely racist comment about getting sick from being around data/vaccine types in the next to last episode of Adventure. (At least in the english dub.)
Stormy Wizard
Guest
Ah, I sort of get it now, Data type digimon are able to easily change into vaccine and virus types while vaccines and viruses don't normally change their types.
Patamon (data) --> Angemon (Vaccine) --> MagnaAngemon (Vaccine), etc
Demiveemon (data) --> Veemon (Vaccine) --> ExVeemon (Vaccine), etc
I don't know any digimon that change from Vaccine to Data naturally, ie, that follow a set digivolution path, or even virus to data. So, Data must be the neutral area after all, and once a digimon has the side that they're on (vaccine or virus) then they remain that way until they de-digivolve.
I think a non-digimon virus could also affect an already hatched digimon as well.
Look at Tsukaimon, it looks exactly like Patamon except it's purple. Say for argument’s sake that a virus got into a Tokomon just as it was nearing the time it would digivolve to Rookie. Now Patamon is a Data type but Tsukaimon is a virus type, that could explain how you get variations of the same basic appearance for some digimon.
Now as for the same type of digimon that look alike but have differences, Angemon/Piddomon, both vaccines it may work like this: one of them has a higher vaccine ratio in it's programming than the other. The same could be said about a virus' ratio in digimon like Devimon/IceDevimon.
Admittedly kind of a weak theory but it works.
Hey people just found a Virus that digivolves to a Vaccine:
Antylamon is a virus and while there is a virus type Cherubimon, Antylamon can digivolve into the "purified" vaccine version as well.
I think that kind of blows holes in my type theory, or maybe it's one of those exception that tests the rule kind of things. Oh well, I think the base of the theory still works.
Stormy Wizard
Guest
I've come up with the 'ridge' theory to clarify things a bit.
A data digimon grows as if it is moving along a 'ridge' with two downward slopes on each side. As it digivolves, it can either fall left (vaccine), right (virus) or keep going along the ridge (data). It's a bit odd I know, but it sort of makes sense if you think about it.
I see what you mean, the ridge theory makes sense to me.
Reminds me sort of like in Seiken Densetsu 3 you could classchange along the paths "Light" or "Dark", twice...
Looking through my index, I find very few VIRUS Digimon that actually do become Vaccine types (except Cherubimon in Frontier who was briefly changed back from his "corrupted" form into the "Vaccine" Cherubimon) through NORMAL evolution.
Wormmon can become Bullmon (Virus -> Vaccine) through an Armor evolution, and CAN become Angemon (Vaccine only), Airdramon (Vaccine only), Coatlmon (Armor evolution), Puttimon (Armor evolution), Revolmon, Sorcerymon, and XV-mon (all of these are Vaccine only).
It's far more common to find Digimon which go from Vaccine to Virus, which leads to my theory: Virus digimon are partly a result of a corruption of parameters, and partly a result of their nature. At low levels it's purely their nature, I believe, but because many Rookie Digimon can evolve from Virus to Vaccine, I think the "corruption" can be fixed, sort of a nurture vs. nature thing.
It's hard to understand exactly how it all works out, but I think level has a lot to do with the attribute -- few, if any, Champion level Viruses become Vaccines, though a number of Vaccine Digimon can become viruses.
:!: