I need help finding a manhwa bl

I cant fully remember it but i di remember its like in an apocalyptic genre in which the mc is a researcher(?) And the ml is also one (i think???) then there was this virus(?) Or was it a zombie(?) But basically the ml is infected and the mc doesnt know it and basically the mc trynna find a cure. Its one of those more rich/powerfuk gets safer space iirc he also went back to his university that has a research lab and uhhh i think the ml caught the mc in the sewer hmm its really blurry but its no rainbow city