Question

Why might it be more difficult to prepare a vaccine against noroviruses than against rotaviruses?

Answer 1

Designing efficacious norovirus vaccines remains a major challenge due to several factors:

(1) the extreme genetic variability within the norovirus family and within genogroups

(2) the rapid evolution of antigenically dissimilar pandemic GII.4 norovirus strains

(3) the lack of lasting immunity upon natural exposure to noroviruses in at least a proportion of the population.