Nope meds don't work on virus.
You need to issolate the healthy fish, as when the growth burst in will infect the other fish.
Get you some more info.
Taken from this link.
<a href="http
/www.fish-disease.net/diseases.htm" target="_blank">http/www.fish-disease.net/diseases.htm</a>
Lymphocystis
Symptoms:
Fish infected with Lymphocystis will present with clusters of whitish, berry-like growths on the skin and fins. These "clusters" may resemble small clutches of eggs or cauliflower (hence, it is sometimes called Cauliflower Disease). They will be clearly visible and may even become extremely large. This disease often affects the fins first.
Cause:
Viral infection. The virus will eventually kill the fish if it is unable to mount a strong enough immune response as the virus rampages through the fish’s tissues, destroying its cells.
Treatment:
As with all viral infections, there is no suitable cure or efficacious treatment; however Quick Cure claims to be helpful. I have also heard of people who trim the fish's fins, followed by several baths in Malachite Green. Fortunately, this disease is uncommon and in some cases, infected fish are able to recover quickly without treatment.
Lymphocystis is highly infectious. When infected cells from the fish’s skin or fins burst the virus is spread throughout the aquarium and can remain contagious for periods of up to two months. Fish not showing symptoms should be removed from the aquarium and placed in quarantine, away from other fish, for at least 60 days. Note, remove uninfected fish, not the other way around because the aquarium has become contaminated. The infected aquarium should be emptied and thoroughly disinfected before returning any fish to it. Do not use soap to clean the aquarium.
