penicillin

Injectable penicillin is the go-to treatment for syphilis and the only treatment considered safe for pregnant people with the disease.

The shortage comes as there has been a steady increase in rates of syphilis since 2000. Inventory can start depleting as early as this month, Pfizer said.

The medication is the only one available to prevent an infected pregnant woman from passing the disease to a fetus. Pfizer says the shortage should be over in July.