How is the Critical Immunization Threshold Calculated?
The CIT is calculated based on the basic reproduction number (R0) of the disease. The R0 represents the average number of secondary infections produced by one infected individual in a completely susceptible population. The CIT can be determined using the formula:
CIT = 1 - (1/R0)
For example, if the R0 of a disease is 5, the CIT would be:
CIT = 1 - (1/5) = 0.8 or 80%
Thus, 80% of the population would need to be immunized to prevent sustained transmission.
