I figured out how the vampirism was spread about a minute before I heard it in the story, and just started LOLing.
Of course, I was eating breakfast when the cure was explained. Um... yeah, okay, fine, it's natural and stuff, but I really don't like to hear about blood and such while I'm eating.
I enjoyed the story. I found it humorous and relatively accurate in terms of adolescence, at least in my own experience. (My summer camp didn't have vampires, but I did have a friend Sonya. She liked to pull hair. It hurt.)
I too saw the needles as Chekhov's gun.
Also someone noted the change in attitudes to homosexuality between women and men, I took this as not the writer's opinion but just her good writing of her main character. I'm pretty sure adolescent girls would find those kinds of urban myths gross.
I would never accuse this author of homophobia, but I do think you need to pay attention to the unintended side-elements of your work when you write, lest you accidentally send messages other than the one you want to send. In this case, I bet that the author either didn't notice ("Really? You read it that way? Huh... oops.") or decided that it didn't matter ("This story is for adolescent girls, some of which will be gay or bisexual - hence that out lesbian teen - not for boys, so I don't care if someone reads an unfortunate message into my story."). I don't think the author meant it. That doesn't mean it isn't there.
To me I assumed that the difference in attitude was not of a male/female homosexuality attitude, but just a matter of basic health. I don't think it's unreasonable to be bothered by the ookie cookie while not being bothered by other homosexual encounters, because of the potential for spreading STDs when you take turns eating a cocktail of sex fluids of a bunch of other people about whom you know little or none of their sexual history.
I think it's a combination. To adolescents (which, these days, extends to the mid-20s and later, sadly), female homosexuality is pretty and sexy, while male homosexuality is gross and disgusting. In fact, even among the other 30-year-olds with whom I have lunch on a regular basis, the anti-male-homosexual bias is quite alive and well. Rumors about our CEO are bandied about with impunity, negative stereotypes are used, and in general it's pretty unpleasant. Especially for me, because my best friend in the world since we were six came out to me when we were 19. I'm happy with whatever makes him happy, and in general I'm happy with whatever people do together so long as it does not cause non-consensual harm.
Plus, marketing: marketing using lesbians is HAWT AND SEXAY; marketing using gay guys is seen as EVIL AND WRONG.
I really could go on about this for a long time, but I'll cut it short. I really don't want to fall down this rabbit-hole.
(I happen to be in the southeastern US. Opinions and attitudes differ across the world.)