Title: The Benefits of a Segmented Genome: Influenza
Abstract: Influenza is caused by a virus with a segmented RNA genome. The virus can infect humans, pigs and other mammals and birds. The viral envelope contains two key proteins, haemagglutinin (HA) and neuraminidase (NA). There are sixteen known variants of the HA and nine of the NA. During an infection, HA binds to receptors on airway epithelial cells. Human influenza viruses and bird influenza viruses have different receptors. Some animals, such as pigs have both types of receptors. NA removes sialic acid residues from viral glycoproteins and plays a role in the infection process. The RNA polymerase of influenza is error-prone and this results in mutations in HA and NA (antigenic drift). Some of these mutants are more infectious and cause seasonal influenza. If an avian influenza virus and a human influenza virus infect an animal with both virus receptors, such as a pig, reassortment of the eight RNA segments from each virus can occur. If any of the 256 possible new combinations (antigenic shift) has increased virulence then it can cause a pandemic. Seasonal vaccination of those most at risk is the best preventative strategy but occasionally the virus changes in unexpected ways and the vaccines in use have reduced effectiveness.
Publication Year: 2022
Publication Date: 2022-03-24
Language: en
Type: book-chapter
Indexed In: ['crossref']
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