Paediatrics - Childhood immunization Flashcards
Hong Kong Childhood Immunization Program.
Vaccines given at:
Newborn?
1 month?
Newborn:
B.C.G Vaccine
Hepatitis B vaccine - 1st dose
1 month:
Hepatitis B vaccine - 2nd dose
Hong Kong Childhood Immunization Program. Vaccines given at: 2 months, 4 months, 6 months?
2 months:
DTaP-IPV - 1st dose
PCV13 - 1st dose
4 months:
DTaP-IPV - 2nd dose
PCV13 - 2nd dose
6 months:
DTaP-IPV - 3rd dose
Hepatitis B - 3rd dose
Hong Kong Childhood Immunization Program.
Vaccines given at:
12 months
18 months
12 months:
MMR - first dose
PCV13 - Booster dose
Varicella - 1st dose
18 months:
DTaP-IPV - Booster
MMR - 2nd dose
Hong Kong Childhood Immunization Program. Vaccines given at: Primary 1 Primary 5 Primary 6
P1:
DTaP-IPV - Booster
P5:
9-valent HPV vaccine - 1st dose
P6:
9-valent HPV vaccine - 2nd dose
List 2 vaccine not under Hong Kong Childhood Immunization Program.
Haemophilus Influenza type B vaccine
Rotavirus vaccine
Difference between active and passive immunization
Active = antigen, elicit immune response and long-term memory Passive = Immunoglobulin (Ig), Short-term protection
List 5 types of vaccines
- Live attenuated organism
- Killed whole organism
- Inactivated exotoxin
- Subunit
- Subunit conjugated
Define and give Example of live attenuated vaccine
Attenuated/ weakened form of virus of bacteria that replicate
Immune response similar to natural infection
Varicella
BCG
Chicken pox
MMR
Define and give Example of killed whole organism vaccine
Whole cell Pertussis
IPV (polio)
HAV
Define and give Example of inactivated exotoxin vaccine
Diphtheria toxoid
Tetanus Toxoid
Define and give Example of Subunit vaccine
Acellular pertussis
Pneumovax
Define and give Example of Subunit conjugated vaccine
Hemophilus influenzae type B
Pneumococcal vaccine
3 disadvantages of live attenuated vaccines
Severe reaction possible
Interference from circulating antibody (e.g. IV Ig can counteract the vaccine effects)
Unstable - require special storage and transport
Advantages and Disadvantages of Inactivated vaccines
Advantage:
- Minimum interference from circulating antibody
- Cannot replicate, rare severe reaction
- Humoral immune response
Disadvantages:
- Less effective than live vaccine
- Require 3-5 doses (primary + booster)
- Antibody titer falls over time
Define 2 types of vaccine failure
Primary = Vaccine fail (e.g. spoiled from poor storage, contaminated)
Secondary = No host response
Time gap between vaccine and antibody admin.
Vaccine given first = Wait 2 weeks before giving Ab
Ab given first = wait >3 months before giving vaccine
High dose Ab need even longer
2 reasons why HK has not implemented Hemophilus influenza type B vaccine in program
HiB Universal vaccination not implemented because:
- Low mortality rate and Low disease burden in HK (mostly in middle east and Africa)
- Cost of vaccines - only available in private sector with 50% coverage
Varicella virus:
- Reservoir
- Transmission
- Temporal pattern
- Communicability
- Reservoir = human
- Transmission = airborne droplet, direct contact with lesion
- Temporal pattern = peak in winter, early spring
- Communicability = 1-2 days before rash until 4-5 days after. Longer if immunocompromised
Varicella pathogenesis pathway
Repiratory transmission»_space; Replication in nasopharynx and regional lymph nodes»_space; repeated episodes of viremia»_space; Multiple organs and tissue infected (including sensory ganglia)»_space; vesicular rash on skin
4 types of lesions present: red nodule > vesicle > pustule > crust/ scar
Reactivation of varicella virus?
Dormant in Dorsal root ganglion
> > reappear as shingles: Groups of lesions unlike isolated dots in chickenpox
3 complications of Varicella infection
- Bacterial infection of lesions: skin sepsis and impetigo, necrotizing fasciitis
- CNS: Reye’s syndrome, Cerebellar ataxia
- Pneumonia
Which people have increased risk of complications from Varicella
Normal adults infected for the 1st time (young children cope much better)
Immunocompromised
Newborn with maternal rash: onset after delivery
Congenital Varicella Syndrome.
- Cause
- Period of risk
- Symptoms
Maternal infection during pregnancy > vertical Tx
Period of risk through first 20 weeks to pregnancy
Atrophy of extremities, Skin scaring, Low birth weight, Neurologic abnormalities
Varicella Vaccine
- Composition
- Efficacy
- Duration of immunity
- Schedule in vaccine program
Live virus vaccine
95% efficacy (mostly mild reaction illness without complication)
>7 years immunity
1st dose at 1 year old
2nd booster at 18 months
Rotavirus vaccine efficacy
- High in industrialized and middle income countries, 96% effective against severe rotavirus gastroenteritis
Which populations are most at risk of influenza and require vaccine.
Children from 6m to 5 years
Pregnant women
Elderly >= 65 (+/- living in residential care homes)
Healthcare workers
Poultry workers
Chronically ill/ disabled
Program for children influenza vaccine?
Efficacy and coverage?
School Outreach Vaccination program for all primary schools and kindergartens
Doubles coverage to 70%
Vaccine efficacy = 45.3% against influenza-like-illness
3 types of pneumococcal vaccine?
PCV7,10,13
Protects against 7,10 or 13 serotypes of pneumococci
4 diseases that are associated with pneumococcal infection.
Meningitis
Empyema
Necrotizing pneumonia
Septic shock
Which pneumococcal serotypes are implicated in Necrotizing pneumonia, empyema, septic shock, fatality rate?
Serotype 3** and 19A
Which pneumococcal vaccine can protect against empyema?
Only PCV13
Coverage for Serotype 1,3,5,7F,8,19A
Efficacy of pneumococcal conjugate vaccines against clinical pneumonia vs CXR-positive pneumonia.
How does pneumococcal vaccine protect against infection?
Clinical = 8%
CXR +ve = 36%
Direct protection against colonization in nasopharynx, direct protection against disease in lungs or bacteremia
Which pneumococcal serotype is causing an increase in invasive pneumococcal disease? Which vaccine type is failing?
Serotype 3 is causing increase in invasive pneumococcal disease in aged 2-4 and 5-17
PVC13 failing
Pneumococcal vaccine failure is predominant in which serotype?
Serotype 3
Efficacy of PCV10 vs PCV13?
Similar
due to PCV13 serotype 3 failure
Major barrier for using PCV vaccines?
- PRICE ***
- Serotype 3 failure
