What is herd immunity? How is this achieved? Why is this a public health priority to reduce the prevention of the spread of infectious diseases?

1. What is herd immunity? How is this achieved? Why is this a public health priority to reduce the prevention of the spread of infectious diseases?

2. What is the herd immunity threshold for measles (hint: red line 9:05 in Ted Talk)? Share the recommended vaccination for children and when should it be administered?