Vaccines Flashcards
Explain how vaccines elicit an immune response and provide protection from disease
Memory from Adaptive Immunity is the basis of vaccination program
- The first exposure to an antigen leads to development of a primary immune response with proliferation of activated B cells and T cells into effector cells and some to memory B cells and T cells.
Live attenuated vaccine?
virus is weakened, often by repeatedly passing it through a tissue culture which it replicated poorly
+:• Activates killer T cells
• 1/2 doses can provide lifelong immunity
-: • Must be refrigerated
• Less safe for ppl with weakened immune systems
E.g. Measles, mumps, rubella, varicella, rotavirus
Inactivated vaccine?
Pathogen is treated with heat or chemicals to kill it before it is introduced into the body
+: • Easy to store and transport
• Low risk of causing an infection
-: • Elicits weaker immune response
• May require several doses and boosters
E.g. Polio, hep A, rabies
Subunit vaccine?
One or more parts of the pathogen, e.g. protein, are isolated and used to evoke and immune response
+: • Low risk of adverse reaction
• Can be used in people with weakened immune systems
-: • Can be difficult to manufacture
• May require boosters
Toxoid vaccine?
Toxin produced by pathogen instead of pathogen itself, is deactivated & used to produce immune response
+: • Unable to cause disease or to spread
• Stable so ez to dist
-: • May require boosters to maintain immunity
E.g. Diphtheria, tetanus
Recombinant vaccine?
Vaccines produced using genetic engineering. Contain modified strain of the virus (no actual virus)
E.g. Hep B, HPV
Vaccines against respiratory infections?
Influenza Pneumococcus Meningococcus Diphtheria, pertusis H.Influenzae MMR Chickenpox BCG (tuberculosis)
Vaccines against food & water infections?
Hep A, typhoid, cholera, rotavirus
Vaccines against vector-borne infections?
Yellow fever
Japananese Encephalitis dengue
Blood & body fluids
Hep B
HPV
Contact
Tetanus
Rabies
Shingles
List the vaccines in Singapore’s childhood immunization schedule
- Bacillus Calmette-Guerin (BCG)
- Hep B
- Diphtheria, tetanus & acellular pertussis (paediatric) (DTaP)
- Tetanus, reduced diphtheria & acellular pertussis (Tdap)
- Inactivated poliovirus (IPV)
- Haemophilus influenzae type b (Hib)
- Pneumococcal conjugate (PCV10 or PCV13)
- Pneumococcal polysaccharide (PPSV23)
- Measles, mumps and rubella (MMR)
- Varicella (VAR)
- Human papillomavirus (HPV2 or HPV4)
- Influenza (INF)
List the vaccines in Singapore’s adult immunization schedule
- Influenza (INF)
- Pneumococcal conjugate (PCV13)
- Pneumococcal polysaccharide (PPSV23)
- Tetanus, reduced diphtheria & acellular pertussis (Tdap)
- Human papillomavirus (HPV2 or HPV4)
- Hep B
- Measles, mumps and rubella (MMR)
- Varicella (VAR)
C/I of vaccines?
- Allergy to vaccine or components
- Moderate/severe illness (fever >38C)
- Bleeding risk (on anti-coagulation/ low platelet counts)
- Pregnancy (live vaccines)
- Infancy (live vaccines)
- Immunocompromise; including those on high conc of steroids (live vaccines)
exceptions to simultaeneous administration of vaccines?
- Pneumococcal conjugate vaccine (PCV) and meningococcal conjugate vaccine
in patients with functional or anatomical asplenia . 4‐week interval between the administration of the two vaccines to avoid interference of the meningococcal conjugate vaccine with PCV - Live vaccines administered via intramuscular or subcutaneous route to be spaced 28 days apart
