Is there a cure for the plague?

Yes, antibiotics. Patients with suspected plague are put in strict isolation units and treatment is started with antibiotics such as gentamicin, streptomycin, doxycycline, tetracyline, Septra, (sulfamethoxazole and trimethoprim) ciprofloxacin, or chloramphenicol. With treatment, the death rate drops from about 50% to about 15% (the majority of the cases are bubonic plague). Pneumonic plague is fatal if treatment is not started in 24 hours.
Plague. The plague - bubonic plague - is caused by a particular bacteria. When it wiped out populations it was because fleas spread it and there were no antibiotics at the time. Now there are classes of antibiotics that kill the yersinia bacteria that causes it.
Yes. Several common antibiotics are effective against the plague microbe. The key is making the diagnosis. Today cases are sporadic and caught from wild animals. Nobody actually knows how many people are cured because of shotgun antibiotic therapy of people who are sick and have fevers and big lymph nodes.