system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Positive Schick test indicates that the person is:
assistant
The correct answer is  Positive Schick reaction: 
This is characterized by a local inflammatory reaction that reaches maximum intensity in 4–7 days in the test arm and then reduces gradually. This indicates the absence of an immunity to C.diphtheriae.
Parija SC. Textbook of Microbiology & Immunology. Elsevier Health Sciences; 2014. Page:219