Part of immune evasion pathogen survival strategy

Envelope has two important proteins:

HA- attaches to host receptors (15 variants)
NA- breaks down sialic acid to allow budding (9 variants)

Antigenic drift: Minor mutations occur as a result of low fidelity viral polymerase (rapid replication= fast polymerase= less accurate)

Antigenic shift: Major reassortment of genomic segments caused by two viruses that infect different species infecting a cell simultaneously and recombining genetic material

Epidemics: associated with antigenic drifts, cause seasonal flu outbreaks, cycle 2-3 years

Pandemics: associated with antigenic shifts, worldwide outbreaks of increased severity, cycle 10-40 years

	Criado por Chloe Cavarretta mais de 7 anos atrás

L4 Immunology

3. Antigenic Variation