IID 23 and 24: Immunizations Flashcards
What are the 6 factors that contribute to vaccine hesistancy?
- cognitive bias
- negativity bias
- confirmation bias
- omission bias
- naturalness bias
- risk perception
What is cognitive bias?
perception of reality based on how information is received – pattern recognition
- ie. parents notice delay in language development (1st birthday) or sudden loss of previous functioning (up to 3rd birthday) and relate delays to something recent in child’s life (ie. vaccines)
What is negativity bias?
focusing on the negative (what went wrong vs. what went right) – human nature
- explanatory attribution – search for reasons why something bad happens, need to blame (personal vs. external)
- ie. parents’ inability to understand onset of autism
What is confirmation bias?
tendency to more readily, and with less scrutiny, accept information – anecdotes, personal views, etc.
- trying to convince someone that a previously held belief is incorrect can actually increase their affinity for that idea
- available info can be confusing – default choice is to take NO action
- ie. parents who think about vaccines before their child is born are 8x less likely to vaccinate their children
What is omission bias?
judging harmful actions as less moral than harmful inactions
- ie. when choice to vaccinate is framed as action/choice, the average parent will only vaccinate their child if not vaccinating is at least 2x more dangerous – perception of future regret
What is naturalness bias?
tendency to perceive things that come from nature to be inherently less threatening compared to human-made substances
- ie. synthetic medicine vs. herbal, natural immunity vs. vaccination
What is risk perception?
subjective judgement that people make about characteristics and severity of risk, failure to appropriately quantify risk
- ie. parents weigh disease they have seen (ie. autism) against disease they have not seen (ie. measles) – immediate vs. long-term risk
- ie. success of vaccines may influence why parents are less likely to vaccinate their children
What is the recommended immunization schedule for Tdap?
- 2 months
- 4 months
- 6 months
- 18 months
- 4-6 years
- grade 9
- diphtheria and tetanus booster every 10 years
What is the recommended immunization schedule for polio?
- 2 months
- 4 months
- 6 months
- 18 months
- 4-6 years
What is the recommended immunization schedule for H. influenzae type B (HiB)?
- 2 months
- 4 months
- 6 months
- 18 months
What is the recommended immunization schedule for hepatitis B?
- 2 months
- 4 months
- 6 months
What is the recommended immunization schedule for rotavirus?
- 2 months
- 4 months
What is the recommended immunization schedule for pneumococcal?
- 2 months
- 4 months
- 12 months
What is the recommended immunization schedule for meningococcal?
- meningococcal C: 2 and 12 months
- meningococcal A, C, Y, W-135: grade 9
What is the recommended immunization schedule for MMR?
- 12 months
- 4-6 years
What is the recommended immunization schedule for varicella?
- 12 months
- 4-6 years
What is the recommended immunization schedule for influenza?
annual – for children ≥ 6 months
What is an additional recommended vaccination for Indigenous children?
hep A vaccine at 6 and 18 months
What is the recommended immunization schedule for HPV9?
grade 6 – 2 doses at 6 months apart
Diphtheria
Corynebacterium diphtheriae
- spread by nasal droplets
- affects tonsils, throat, nose, skin, heart
- signs and symptoms: severe pharyngitis, cervical adenopathy
- toxin → myocardial and neurological complications
Tetanus
(lock jaw)
Clostridium tetani
- found in soil and animal feces
- signs and symptoms: painful muscular contractions, convulsions
Pertussis
(whooping cough)
Bordetella pertussis
- spread by cough and nasal droplets
- produces toxins that paralyze respiratory cell cilia
- signs and symptoms: runny nose, cough
- complications: bacteria pneumonia, seizures, encephalopathy
- usually not serious in older children and adults, but they can give it to younger child
What is the catarrhal stage (1-2 weeks) of pertussis?
runny nose, sneezing, low-grade fever, mild cough
What is the paroxysmal stage (1-6 weeks) of pertussis?
bursts of coughs, thick mucus, long inspiratory effort (with high-pitched whoop), vomiting, exhaustion
- appears normal between attacks
What is the convalescent stage (2-3 weeks) of pertussis?
gradual recovery
What is the DTap vaccine?
diphtheria, tetanus, acellular pertussis
- dose: 0.5 mL IM
Poliomyelitis
poliovirus (enterovirus)
- inhabits GI tract
- spread by feces and saliva
- viral replication in motor neurons (spinal cord and CNS)
- signs and symptoms: fever, headache, nausea and vomiting, muscle weakness, paralysis
What is the vaccine for poliomyelitis?
eIPV (enhanced potency inactivated polio)
- 3 doses: 99-100% seroconversion
- 4 dose: lifelong immunity
H. influenzae Type B (HiB)
Haemophilus influenzae, B serotype
- spread via nasal droplets
- common cause of bacterial meningitis (chance of permanent neurological sequelae, deafness), epiglottitis, pneumonia, bacteremia in children
What is the H. influenzae Type B (HiB) vaccine?
- conjugate vaccine – organisms’ capsule
- > 59 months (5 years): natural immunity, therefore revaccination not required
Hepatitis B
- virus
- risk factors: blood transfusion, needle stick accident, IVDA, sexual contact, vertical transmission, breastfeeding
- signs and symptoms: asymptomatic, flu-like illness
- sequelae: hepatic failure, liver cancer, death
What is the hepatitis B vaccine?
Recombivax-HB, Energix-B
- inactivated vaccine:
- recombinant HBsAg
- 3 doses
- titres 1-2 months post
- deltoid muscle – immunogenicity lower in buttock
What is the quadrecel vaccine?
dTaP, IPV
- dose: 0.5 mL IM
What is the pediacel vaccine?
dTaP, IPV, HiB
- dose: 0.5 mL IM
What is the infanrix-hexa vaccine?
dTaP, IPV, HiB, HepB
- dose: 0.5 mL IM
S. pneumoniae
Streptococcus pneumoniae
- common bacterial pathogen in URTIs, childhood meningitis, pneumonia
- varying prevalence and invasiveness
What are the 2 vaccines for S. pneumoniae?
- pneumococcal 7-valent vaccine (PCV7)
- pneumococcal 23 vaccine
What is the pneumococcal 7-valent vaccine (PCV7)?
Prevnar 13®
- dose: 0.5 mL IM
- conjugate
- more than 90% effective
What is the pneumococcal 23 vaccine?
Pneumovax23® and Pnu-Immune 23®
- dose: 0.5 mL IM or SC
- polysaccharide
- Ab levels elevated for children 3-5 years, NOT effective in children < 2 years
- recommended for: 2-64 years at high risk of invasive pneumococcal disease, ≥ 65 years of age, residents of long-term care facilities
What is the timeline for S. pneumoniae vaccines?
- 2 months: PCV13
- 4 months: PCV13
- 6 months: PCV13
- 12-15 months: PCV13
- (PPV23 8 weeks after in high risk groups)
- 2 years: PPV23
- 7 years: PPV23
What are conjugate vaccines?
- created by attaching polysaccharide molecule to carrier protein to create T-cell dependent response that establishes B cell memory
- provide longer-lasting production
- part of routine childhood immunization schedule
What are polysaccharide vaccines?
- made of long chains of sugar molecules that resemble the surface of certain bacteria, which stimulates independent T-cell response but no B-cell memory
Meningococcus
spread by close direct contact (kissing, coughing, sneezing), or through saliva (sharing of cigarettes, lipstick, food/drink, toothbrush, toys, mouth guards, musical instruments, etc.)
What are the 3 vaccines for meningococcus?
- Menjugate
- Menactra
- Mencevax AC
What is the Menjugate vaccine?
meningococcus C conjugate vaccine
- dose: 0.5 mL IM
- effective in infants and children < 2 years
- part of routine childhood immunizations
What is the Menactra vaccine?
N meningitidis A, C, Y, and W-135 ‘conjugate’ vaccine
- dose: 0.5 mL IM
- polysaccharides linked to protein (diphtheria toxic)
- children > 2 years, teens, adults
- part of public plan in BC for all in grade 9, and people at ↑ risk of meningococcal infection
What is the Mencevax AC vaccine?
N meningitidis A, C, Y, and W-135 polysaccharide vaccine
- dose: 0.5 mL SC
- for children ≥ 5 years and adults
Measles
virus: paramyxovirus
- spread by cough and nasal droplets
- signs and symptoms: fever, sore throat, cough, runny nose, red rash
- pneumonia, encephalitis, subacute sclerosing panencephalitis (SSPE)
Mumps
virus: paramyxovirus
- spread via saliva
- signs and symptoms: fever, parotitis
- sequelae: encephalitis, orchitis/oophoritis, infertility, deafness
Rubella
(German measles or third disease)
virus: togavirus
- spread via nasal droplets
- signs and symptoms: fever, headache, itchy eyes, cervical adenopathy, rash, arthralgias, arthritis
- sequelae: encephalopathy
- infections in first 10 weeks of pregnancy: 85% risk of CRS (congenital rubella syndrome – cataracts, deafness)
What is the MMR vaccine?
- dose: 0.5 mL SC
- live attenuated vaccine
- produces subclinical, non-communicable infection – some children develop rash
- 1st dose: 95% seroconvert
- 2nd dose: 100% seroconversion
- must be > 12 months old – maternal Ab neutralize vaccine (no effect)
Varicella
(chicken pox)
virus: similar to herpes viruses
- serious infection in adolescents and adults
- spread via coughing, sneezing, or contact with chickenpox sores
- signs and symptoms: itchy rash with up to 500 sores, fever, sore throat
- complications: shingles and post-herpetic neuralgia, pneumonitis, encephalitis, death
What is the vaccine for varicella?
- dose: 0.5 mL SC
- live attenuated vaccine
- lyophilized powder, stable for 30 mins once reconstituted
- 70-95% effective, milder disease
What is the MMRV vaccine?
- dose: 0.5 mL SC
- live attenuated vaccine (Priorix-Tetra®)
- concerns regarding risk of febrile seizures in young children – still give separate MMR and varicella vaccines to 12 month olds in BC
- used for 4-6 year old booster
Influenza
(flu)
virus
- signs and symptoms: fever, headache, cough, rhinitis, myalgia, severe malaise, sore throat
- complications: bacterial pneumonia
- can be fatal in infants, elderly
What is the vaccine for influenza?
- inactivated
- ‘most likely’ strains of influenza, changes each year
- < 9 years require 2 doses 1 month apart for first time receiving
- annual, during influenza season
What is the vaccine for HPV?
HPV9 vaccine
- against types 6, 11, 16, 18, 31, 33, 45, 52, 58
HPV 16 and 18: 70% cervical cancers - HPV 31, 33, 45, 52, and 58: 15% of cervical cancers
- HPV 6 and 11: 90% of anogenital warts
- age 9-14 years: 2 doses, 6 months apart
- age ≥ 15 years or immunosuppressed: 3 doses: 0, 2, 6 months
Who is the HPV9 vaccine publicly funded for in BC?
- individuals of all sexes, genders, sexual orientation, and levels of sexual activity
- recommended for all youth in BC
- part of routine immunization schedule in grade 6
- should get first dose before age 19
- should complete the series before age 26
Rotavirus
- causes gastroenteritis
- symptoms: fever, vomiting, diarrhea, stomach pain
- most common cause of diarrhea and need for hospitalization for dehydration 2º to diarrhea in children < 5 years
- almost all children will have at least 1 rotavirus infection by 5 yrs
What is the vaccine for rotavirus?
RotaTeq®
- dose: 2 mL po x 2 doses, at least 4 weeks apart
- live attenuated oral vaccine
- antacid component to prevent antigen inactivation in stomach
- adverse events (generally rare): irritability, diarrhea, dermatitis, abdominal pain, flatulence, anaphylaxis, intussusception
What are the mild adverse reactions to vaccines in children?
fever, malaise, arthralgia, chills, local site tenderness
What is the treatment for mild adverse reactions to vaccines in children?
- acetaminophen 15mg/kg/dose PO q6h PRN
- ibuprofen 10 mg/kg/dose PO q8h PRN
What are the serious adverse reactions to vaccines in children?
anaphylaxis, seizures, encephalopathy, Guillain-Barre (acute demyelination of peripheral nerves, immune-mediated, progressive motor weakness, areflexia, progresses over 2-3 weeks)
What are the absolute contraindications to vaccines? (2)
- anaphylactic allergies to any vaccine component
- pregnancy
When do we consider delaying vaccines? (2)
- immunocompromised
- moderate or severe acute illness – wait until recovering and no longer acutely ill
