HISTORICAL PERSPECTIVE

EDWARD JENNER

  • The term vaccination is coined from the Latin word “vacca” which means cow.
  • In 1736, Benjamin Franklin’s son died of small pox at age 4
  • In 1751, 3138 people died of small pox in London
  • Small pox used as war weapon in 1776 to preserve British Canada
  • In 1781, a future US president Andrew Jackson contacted small pox at age 14
  • In 1796, he tested and proved the hypothesis that infection with cowpox could protect against small pox, by innoculating 8yrs old James Phipps and the boy made full recovery from small pox within days
  • Public use of vaccination did not start till 1802 in Massa chussettes USA
  • In 1863, Abraham Lincoln contacted small pox and recovered after 4wks

AVIAN DISEASES:TRANSMISSION & ECONOMIC IMPORTANCE

I.INFECTIOUS DISEASES

  • BACTERIAL
  • VIRAL
  • MYCOPLASMA
  • PROTOZOAN
  • MYCOTIC

II.NON-INFECTIOUS DISEASES

  • NUTRITIONAL DEFICIENCIES
  • POISONS & TOXINS
  • GENETIC DISEASES
  • MANAGEMENT FAILURES
  • ENVIRONMENTAL
  • EMBRYONIC
  • HATCHERY DISSEMINATION (Bangers)
  • AEROSOL (Air-borne)
  • FEATHERS
  • LITTER DROPPINGS
  • MIXING OF MULTI-AGE & MULTI-SOURCE BIRDS
  • CONTAMINATION OF FEED & WATER
  • FAECAL CONTAMINATION
  • VECTORS (Man, wild birds, rodents, insects & worms, artificial insemination)

ELEMENTS OF DISEASE PREVENTION & CONTROL

  • BIOSECURITY
  • MONITORING
  • VACCINATION
  • MEDICATION

MECHANISM OF IMMUNITY IN CHICKENS

ORGANS OF IMMUNITY

  • Primary
  • Secondary

DEVELOPMENT OF THE IMMUNE SYSTEM

  • B-cells (humoral immunity)
  • T-cells (cell-mediated immunity)

STIMULATION OF THE IMMUNE SYSTEM

  • Infection
  • Vaccination

PASSIVE AND ACTIVE IMMUNITY

PURPOSE OF VACCINATION

  • “THE PURPOSE OF VACCINATION IS THE STIMULATION OF THE IMMUNE RESPONSE TO OVERCOME A DISEASE”.
  • “A HOST THAT IS MADE RESISTANT TO AN INFECTION BY VACCINATION IS SAID TO BE IMMUNIZED”
  • AN IMMUNIZED CHICKEN EXHIBITS: -formation of antibodies (humoral immunity)  -activated lymphoid cells/macrophages

ADMINISTRATION OF VACCINES IN POULTRY

MASS VACCINATIONS

  • DRINKING WATER
  • NEBULISATION
  • AEROSOL

INDIVIDUAL VACCINATION

  • OCCULAR OR INTRA-NASAL INSTILLATION
  • IN-OVO (EMBRYONIC)
  • INJECTION (I/M OR S/C)
  • WING-WEB PUNCTURE

FACTORS INFLUENCING SUCCESS OR FAILURE OF VACCINATION

  • QUALITY OF VACCINE (Production & Handling)
  • ROUTE OF ADMINISTRATION
  • MANAGEMENT OF VACCINATION PROCESS
  • IMMUNE STATUS OF RECIPIENTS
  • CONCURRENT STRESS FACTORS