True to his epithet, Queen has immense knowledge in virology, having invented extremely infectious and deadly viruses which are contained in his creations the Excite Bullets.
The viruses are powerful enough to affect even Luffy, who developed an immense resistance to poison due to his previous battle with Magellan.
As we have seen in the latest chapter, Daifugo shoots the prisoners with special bullets, which inflict a debilitating virus created by Queen and known as Mummy onto them that is spread through touch. The virus basically eats the person from inside destroying their cells at a rapid speed.
The prisoners with broken spirits move to subdue Luffy’s group, but Luffy unexpectedly grabs them and becomes infected.
As we know Luffy possesses incredible toxin resistance thanks to Ivankov’s help. Nevertheless, the virus spread to his face and he starts bleeding from his nose.
At the end Luffy falls unconscious because of the virus.
So Queen hype is still ongoing good. His plagues have shown to have affects on even poison resistant High Tiers like Luffy, and Queen also got bigger doses of same virus which will have even more impact. This is great ability to have in his arsenal!