An idea that tickled my fancy.
In a different universe, energy-sucking aliens keep well away from the cordyceps-infested, intergalactically-quarantined Earth. There's no (traditional enemy) need (and thus no awakening) for Sailor Scouts but the reincarnations of the princesses can still call upon a degree of their powers, as they discover in times of danger.
Luna finds Usagi, who can heal the recently infected (brain infestation = brain damage, beyond her ability) and the two eke out a life on the streets of a military-run Tokyo who cannot be allowed to find the girl rumored to be capable of curing the infection.
The other Inners are in similar situations, with Artemis urging Minako to find the reincarnated Moon Princess, both to protect and because she might be able to heal the planet some day. Rei is discovering increasing powers over fire and psychic awareness of the dead - aided by the sheer mass of death around her, a drastic reduction in the usual rituals that settle the unquiet dead and the horrible way many of them died. Makoto signs up for the army and is alarmed by incidents of electrical energy discharges from her person during infected attacks, culminating in her deserting for her own (and her comrades') safety. Ami is trying to contribute to the research effort but, although naturally brilliant, most efforts have already been wound down and with her status as both a youth and a girl, she is dismissed and issued a place in the general workforce.
The Outers don't come into it much. Pluto is at the Time Gate and has issued to Haruka and Michiru the duty of guarding Hotaru until the time comes when Earth is judged to be irrecoverable and the only solution is the total destruction (and rebirth) of it all.
I don't have any editing software at the moment so I can't tidy up the above but when I do, I'll move it to scraps.
I know, lots of errors. I'll keep practicing.