Question

4. A study is conducted to determine the efficacy of the influenza vaccine. Subjects agree to participate for 2 years. In year 1, subjects are randomly assigned to be injected with the vaccine or a placebo. In year 2, the subjects who previously received the live vaccine are given the placebo and vice versa. Incidence rates of influenza for both groups over the 2 year period are recorded. a. This is an unethical study b. This is an invalid study c. This is a strong cross over design d. This study cannot establish the efficacy of the influenza vaccine

5. Justify your answer for Question 4 from an epidemiologic perspective

Answer 1

Answer:

The epidemiological perspective if this study:

This study Involves two groups in which one group is given the live vaccine and the other group is given the placebo for the first year.
In the second year the the group which had live action is given placebo and the other group which had the placebo for has been given the live action.

the study duration is so short that we cannot decide the efficiency of the vaccine because the people may not develop the disease within the one year so we have to at least provide them a minimum duration of 3 to 5 years to see whether there is any arising of the disease.

if we are going to conduct the study only for the two years then there should not be cross placing of vaccines between group A and group B .

the efficiency of the vaccine can be identified if the live vaccine is given to one group and the placebo is given to the other group separately without intersecting them.

this study doesn't have any purpose to improve the efficiency of the vaccine.