To explain: The way by which antigenic changes in the viral pathogens promote diseases.
Concept introduction: Antigenic variation is the mechanism in which an infectious agent like protozoa, bacterium and virus change the surface proteins to avoid the immune response from host. Antigenic variation enables immune invasion by pathogens. It will also allow the microorganisms to cause re-infection.
Explanation of Solution
The antigen variations that takes place in the viral pathogens can promote diseases. The antigenic variation that takes place in the viruses consists of six categories called the antigenic drift, shift, and rift, sift, lift, and gift. Usually, antigenic variations are minor and results from mutations.
Influenza A undergoes major antigenic changes. The virus can infect birds and mammals, and shifts occur in the animals coinfected by a human and an avian strain of influenza. The viral genome is segmented and undergoes recombination during which the human virus get new HA or NA antigen. When the shift is not occurred, clinical influenza will be considered as epidemic. When the major antigenic variation occurs, earlier protection may not exist. This results in a major pandemic and much more severe diseases.
Want to see more full solutions like this?
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education