Vaccines Flashcards
What is active immunization?
Stimulating immune system response to create immunologic memory
What is passive immunization?
After exposure to infection, infusing antibodies or immunoglobulins for immediate protection (no time to vaccinate)
Describe live attenuated vaccines and their characteristics (i.e. measles, mumps, rubella, varicella, rotavirus)
Virus weakened via passage in medium where it replicates poorly
+ Activates killer T cells
+ Can provide lifelong immunity with 1 or 2 doses
- Refrigeration needed
- Less safe for immunocompromised pts
Describe inactivated vaccines and their characteristics (i.e. polio, hepatitis A, rabies)
Pathogen treated with heat/chemicals to kill it
+ Easy storage and transport
+ Low risk of infection
- Weak immune response, may require boosters
Describe subunit vaccines and their characteristics (i.e. influenza, hepatitis B, pertussis, pneumococcus)
Can be Protein/Polysaccharide/Conjugated 1 or more parts of pathogen isolated to invoke immune response \+ Low risk of adverse reaction \+ Suitable for immunocompromised pts - Difficult to manufacture - May require boosters
Describe toxoid vaccines and their characteristics (i.e. diphtheria, tetanus)
Toxin produced by pathogen inactivated and used to invoke immune response
+ No risk of infection
+ Stable, easy to distribute
- May require boosters
Describe recombinant vaccines and their characteristics (i.e. HPV, hepatitis B, live oral typhoid)
Vaccines made using Genetic engineering
May contain no actual virus i.e. HPV, Hepatitis B or modified strain of virus i.e. live oral typhoid
Precautions of live vaccines?
Avoid in pregnant women Usually not for infants Avoid in severely immunocompromised pts Avoid another live vaccine in 28 days Space 3-10mnths apart from antibody containing products (blood transfusion/immunoglobulins)
Available vaccines for respiratory transmission?
Influenza, pneumococcus, Meningococcus, Diphtheria, pertussis Hemophilus influenzae Measles, mumps, rubella Chickenpox BCG (Tuberculosis)
Available vaccines for Food/water transmission?
Hepatitis A, typhoid, cholera, Rotavirus
Available vaccines for vector transmission?
Yellow fever, Japanese Encephalitis Dengue
In development: malaria
Available vaccines for blood/fluids transmission?
Hepatitis B, Human papilloma virus
Available vaccines for contact transmission?
Tetanus
Rabies
Shingles
Explain herd immunity
Enough of the population is vaccinated to contain spread of disease, protecting unimmunized individuals
What are the 11 vaccines in the National Childhood Immunization Schedule (NCIS) ?
Bacillus Calmette-Guerin (BCG) Hepatitis B Diphtheria, Tetanus, acelullular Pertussis DTaP (paediatric) --> Tdap (later date) Inactivated poliovirus (IPV) Haemophilus influenzae type b (Hib) Pneumococcal conjugate (PCV10 or PCV13) Pneumococcal polysaccharide* (PPSV23) Measles, mumps and rubella (MMR) Varicella (VAR) HPV2 or 4 Influenza* (INF)
*Recommended for pts with specific medical condition/indication
What are the 8 vaccines in the National Adult Immunization Schedule (NAIS) ?
Tetanus, reduced Diphtheria, acelullular Pertussis* (Tdap) Influenza* (INF) Pneumococcal conjugate* (PCV10 or PCV13) Pneumococcal polysaccharide* (PPSV23) Measles, mumps and rubella (MMR) Varicella (VAR) Hepatitis B HPV2 or 4 (females)
*Recommended for pts with specific medical condition/indication
What are the factors that affect vaccine effectiveness?
Variation by vaccine (Hep B 95% vs Varicella 90%)
Site of vaccination (Hep A/B IM in deltoid, not gluteus)
Patient age and immune status
Cold chain problems
What are some adverse effect of vaccines?
- Mild & common: Pain at injection site, headache, myalgia
- Uncommon: Fever, hematoma
- Severe but rare: Anaphylaxis, hypersensitivity
Contraindication and precautions for vaccine use?
- Allergy to vaccine or components
- Moderate/severe illness (fever > 38C)
- Bleeding risk (on anti‐coagulation or low platelet counts) ‐ precaution
- Pregnancy (live vaccines)
- Immunocompromised (live vaccines)
Most vaccines can be administered simultaneously or within the same day. What are the exceptions?
Pneumococcal conjugate vaccine (PCV) and meningococcal conjugate vaccine in patients with functional or anatomical asplenia
- Space them out in a 4 week interval
Live vaccines should be given 28 days apart
If a patient misses a vaccine dose, what should be done?
Give the dose asap
- Additional doses not required
What is the role of adjuvants in vaccines?
Enhance the body’s immune system
- possibly by keeping antigens near site of injection (for easy access to immune cells)
What is the role of antibiotics in vaccines?
Used to remove contaminants in manufacturing process, removed in final product (residues remain)
What is the role of stabilizers in vaccines?
Ensure components remain stable and effective
- i.e. MgSO4, lactose, gelatin, sorbitol, msg
