The Graph Below Illustrates the Predicted Number of Meningitis Cases

The graph below illustrates the predicted number of meningitis cases with or without herd immunity after the initiation of the meningitis vaccination program in the United Kingdom in 1999.Write a short paragraph comparing the observed number of cases to the predicted number of cases.Assess the predictive value of the model used to generate the graph and how this relates to the prediction of the number of cases that would exist without herd immunity.