Rainbow City
https://www.mangago.me/read-manga/rainbow_city/
no not rainbow city. um from what i can remember the MC and the love interest were not working alongside each other. it was more like they were on opposing forces. the love interest was more of a politician/chaebol. the world was seperate strictly by class and i remember the MC had to kill his own parents bc they were infected with the virus
Monster in the Mist
https://www.mangago.me/read-manga/monster_in_the_mist/
thank you so much
it was a bl thriller manhwa and the MC was insanely smart and was able to go to the most prestigious school in their universe. apparently there was some virus that caused ppl to turn into zombies and the MC was helping survivors escape and go to safety. also im pretty sure the MC was working on a cure or vaccine for the virus. ALSO his love interest worked for the government and was behind the spread of the virus (i think) ??