Question

Antigenic evoution : influenza virus from North America and Asia are sampled In two successive years and plotted in two-dimensional antigenic space. The coordinates of each are (i) North American viruses: (2,1) for 2013 and (4,3) for 2014, and (ii) Asian: (4,18) for 2013 and (5,17) for 2014. (a) how does the maqnitude of antigenic change compare between the two regions? (b)how does the direction of antigenic change compare between the two regions?

Answer 1

(a) The following is the compared maqnitude of antigenic change between the two regions

North America:

[(2,1)] [(4,3)] = 2(4) + 1(3) = 11

Asia:

[(4,18)] [(5,17)] = 4(5) + 18(17) = 20 + 306 = 326

11-326 = -315

(b) The direction of antigenic change compared between the two regions is:

←315

Explanation:

The value to which influenza virus evolves within an specific time and location frame is sometimes measured by the two dimensional antigenic space.