Oh, great. So we have Sunny, who worries too much for Yuu's mental peace to actually protect them, we have Yuu, who's enough of a cretin to start yelling that he's a walking vaccine, and then we have Kanae, who just openly admits to having been infected and cured. Truly, a team of geniuses.
Also, as usual, it feels like manga authors forget people have ears that work even if they don't fill the panel with sound effect bubbles. Kanae should have heard them walking around the car.