Surprised that nobody said this already. But I guess I'll take the honor for it.
Some people said that Queen didn't use Ice Oni virus or any Plague related abilities in general is because it was to represent Sanji's hatred for his family. Queen uses Ichiji's laser, Niji's lightning, Yonji's winch, Sanji's stealth black, etc. against Sanji because that's what he hates the most. Queen always comparing himself to Judge and wants to prove that his science is better than Judge by beating Sanji which he also hates. Queen didn't use Reiju's Poison Pink because Reiju was the only person who take care of Sanji during his childhood. The Sanji vs Queen is supposed to be symbolic and as a way to get revenge against his family (bar Reiju of course) that Sanji despised.