14 - Vaccination Flashcards
Variolation
Pus taken from a smallpox blister and introduced into skin of an uninfected person to confer protection
Who discovered vaccination
Edward Jenner
Discovery of vaccination
Inoculation with cowpox protects against smallpox (closely related)
First human viral disease to be eradicated by vaccination
Smallpox (caused by infection with variola virus) via protective immunity induced by closely related virus (vaccinia virus)
Herd immunity
- Occurs when a large portion of a community becomes immune to a disease.
- The spread of disease from person to person therefore becomes unlikely, protecting susceptible individuals who cannot be vaccinated
Passive immunity
- Administration of antiserum containing preformed antibodies
- Immediate protection against recent infection or ongoing disease
Limitations of passive immunity
Can trigger hypersensitivity, antibodies are degraded very quickly
Active immunity
- Protection induced by person’s own immune system with specificity and memory
- Both humoral and cell mediated
- Can last decades
Types of vaccines
Inactivated, subunit, killed
Passive natural immunity
Antibodies acquired through breast milk or placenta
Passive artificial immunity
Immunity gained through antibodies harvested from another person or animal
Active natural immunity
Immunity gained through illness and recovery
Active artificial immunity
immunity acquired through vaccine
Rabies
- Zoonotic viral disease spread to humans via bite of infected animal
- Virus travels along nerves to reach CNS
- Delay between infection and arrival in CNS means post-exposure prophylaxis can prevent disease
- Most people with symptomatic rabies do not survive
Rabies vaccine
Inactivated vaccine (killed virus), or rabies immunoglobulin are offered, depending on exposure or degree of risk