Alfred was supposed to have killed the Plague Bringer by then, but instead of doing so, the Plague Bringer screamed, and everyone in the area covered their ears in pain as the Plague Bringer screamed like their lungs were about to burst. It was so high-pitched that just listening to it can make one deaf.
After the scream, everyone's ears were ringing, and everyone felt dizzy afterwards, especially for Alfred, who was near the Plague Bringer when it screamed. His left ear is bleeding and seems to have ruptured his eardrum in the process. The moment the Plague Bringer stopped screaming, despite reeling from the scream, Layla forced herself to move and raise her staff into the air.
"A-area Heal!"
Everyone who was hurt by the scream recovered quickly, and even Alfred, who took the brunt of the scream, managed to recover as well. The blood on his ears remains, but it seems the damage that was done earlier has been recovered, and he is not in pain anymore.