Lecture 7- Vaccination Flashcards Preview

Immune system > Lecture 7- Vaccination > Flashcards

Flashcards in Lecture 7- Vaccination Deck (24)
Loading flashcards...
1

Immunisation =

process of rendering a person immune or resistant to an infectious disease. Can be naturally acquired or artificially induced as a result of vaccination.

2

Vaccination

= process of stimulating protective adaptive immunity against a microbe by exposure to its nonpathogenic forms called vaccines.

3

Vaccine =

Live attenuated or killed organisms or microbial components (proteins, modified toxins or RNA) given for the prevention of infectious diseases. Vaccines can also be given as a therapy as a form of postexposure prophylaxis (PEP) following the exposure to a pathogen known to induce a disease.

4

5

active vs passive immunity

  • Active= best form of vaccination
    • Only active will lead to long term protection due to the production of memory cells

6

types of vaccine

live attenuated virus/bacteria

inactivated virus

inactivated toxin

conjugate/ subunit

7

live attenuated virus

rotavirus

influenza 

MMR

varicella zoster virus

8

live attenuated bacteria

BCG

9

inactivated virus

HepA

influenza

rabies

10

inactivated toxin 

diptheria, tetanus

11

conguhate

HepB, HiB

pneumomococaal and meningococcal

12

advantages and disadvantages of live vaccines

13

advantages and disadvantages of inactivates/subunit vaccines

14

Target population

15

Route of vaccine administration

16

 

Immune mechanism

 

  • APC (dendritic) engulf antigens from vaccine- initiating immune response
  • Stimulate CD8 and B cell response
    • Cytotoxic and humoral immunity
  • Long term protection --> memory B cells and plasma cells

17

 

Goals of active immunisation

 

  • Long lasting immune protection
    • Protective antibody (IgM, IgG)
    • Vaccine-specific T cell response (viruses)
    • Immunological memory to allow a quicker and more effective production of the above
  • Herd immunity

18

Herd immunity

'Herd immunity', also known as 'population immunity', is the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection. WHO supports achieving 'herd immunity' through vaccination, not by allowing a disease to spread through any segment of the population, as this would result in unnecessary cases and deaths

 

Importance:

  • Reduces or abolishes the circulation of the pathogen
  • Protects the immunocompromised patients
  • Protects the poor responders to vaccines (2-10%)

19

Immunisations strategies

 

Childhood immunisation (8 weeks up to 14 yo)

  • Routine immunisation (see table)
  • Non-routine immunisation

Adult immunisation

  • >65yo
  • Travelers
  • Medical conditions

20

Absolute contraindications to active immunisation

 

  • Any severe, local or generalized reaction to a previous dose of vaccine (anaphylaxis) 
  • Moderate and severe illness (with fever >38.5∘C) 

21

Special considerations for live vaccines

 

  • Infants born to a mother who received immunosuppressive biological therapy during pregnancy (no live vaccines)
  • Pregnant women (no live vaccines)
  • Allergy to egg (Influenza and Yellow fever vaccines)
  • Allergy to gelatin (MMR, varicella, shingles)
  • Allergy to neomycin, streptomycin, or polymyxin B (pertussis, polio, Tetanus, Shingles, varicella, MMR)

22

No LIVE vaccine in immunocompromised individuals

 

  • Those with primary or acquired immunodeficiency affecting cell immunity
  • Are within 6 months of having received chemotherapy/radiotherapy for malignant and non-malignant diseases
  • Have received bone marrow transplantation
  • Are receiving or have received high doses of immunosuppressive therapy in the past three months (corticosteroids, methotrexate, azathioprine) and in the past 12 months (biological therapies = monoclonal antibodies)

23

Adverse effects

 

  • Common : local reactions, rashes, fever, headache
  • Very rare: anaphylaxis* (1: 1 million) or syncope (fainting)

24

False contraindications to routine vaccines

 

  • Atopy and food intolerance
  • Prematurity
  • Currently breast-feeding or being breast-fed
  • Current antibiotic or topical corticosteroid therapy
  • Personal history of febrile convulsions or epilepsy
  • Underweight or past the age of vaccine recommended by the schedule
  • Pregnant mother (No LIVE vaccine)
  • Egg allergy and MMR vaccine