What is one primary use of immunization registry data in disease surveillance?

• A. Identify susceptible populations
• B. Track disease outbreaks across countries
• C. Predict weather patterns
• D. Schedule immunizations.

Answer: (A)

Immunization registry data are used in disease surveillance to identify susceptible populations—people who have not been vaccinated or have incomplete immunity. By mapping vaccination status by age, location, and vaccine type, public health teams can spot gaps in immunity, target outreach or catch-up campaigns, and allocate resources to areas at higher risk. This helps explain and anticipate where transmission is most likely to occur and informs prevention efforts. Other options don’t fit as well: tracking outbreaks across countries relies on broader surveillance networks beyond individual vaccination records; predicting weather is unrelated; and scheduling immunizations is a program function, not the primary surveillance use of these data.