Would an injection of Vampire blood wipe it out? Prevent you from being infected again? Would people even take Vampire blood if it cured / prevented them from getting Cornoavirus. People aren’t even sure they want to take the current RL vaccine, not sure the masses would accept Vampire Blood 🙂
As for Singh, he’d do whatever the Elders or Tatiana wanted him to do. If the Vampires felt the coronavirus was going to have a significant affect on their blood supply, they may direct Singh to help out.