Instead of entering the next room turn around and head back up the stairs, toward the room you began in, to find the door closed. The woman, Iosefka, will be unwilling to let you inside, but she will offer a Iosefka’s Blood Vial instead. She will continue to give you one of these as long as you do not currently have one already.
You can now return down the stairs to the clinic to encounter the Scourge Beast again, defeating him to continue.
The next room contains Blood Vial x2 on the body in the left corner and before exiting through the gate make sure to grab the Quicksilver Bullets x10 in the yard.