Chūntiān de huāfěn guòmǐn ràng rén fángbùshèngfáng.
Spring pollen allergies are impossible to avoid.
Tips
grammar
胜 here means 'to bear / to handle fully' (same 胜 as in 不胜枚举). Literal reading: 'guarding against it is more than guarding can bear' — the defenses can't keep up with the attacks.
usage
Often follows 让人 or 令人. Used for anything that comes at you from too many angles: scams, sneak attacks, bad luck, allergens.