Pharm 428
September 14, 2004
Paediatric Immunizations
Allison Dekker, BSP, RPh
allison.dekker@sickkids.ca
1. The Pharmacist’s Role
- ensure parents are informed about benefits and risks of immunizations
- be a resource for questions regarding new immunization products
- help parents manage adverse effects
- report vaccine-related adverse reactions
2. Immunization Resources
a. For health professionals
- Canadian Immunization Guide (6th edition – 2002)
www.hc-sc.gc.ca/pphb-dgspsp/publicat/cig-gci/index.html
- Canadian Paediatric Society
www.cps.ca
- Compendium of Pharmaceuticals and Specialties (purple pages)
b. For parents
- Your Child’s Best Shot (available from the Canadian Paediatric Society)
- Caring for Kids website www.caringforkids.cps.ca
- Government of Ontario website (includes a link to information sheets in different
languages) www.health.gov.on.ca/english/public/pub/pub_menus/pub_immun.html
- Canadian Immunization Awareness Program www.immunize.cpha.ca
cpha = Canadian Public Health Association (a coalition of organizations including the
Canadian Pharmaceutical Association)
3. Definitions
a. passive immunization
- administration of preformed antibodies as immune globulin or monoclonal
antibodies
- produces temporary immunity; often given post-exposure to decrease risk
of developing disease
- examples: rabies IG, palivizumab
b. active immunization
- the body actively produces antibody in response to the
vaccine or toxoid
- toxoid = modified bacterial toxin which stimulates the production of
antibodies versus the toxin, not the actual bacterium (i.e. tetanus)
c. live attenuated vaccines
- contain altered, weakened, or avirulent microorganisms
- provides strongest immunity, closest to that of natural infection
- examples: MMR (measles mumps rubella), varicella
d. inactivated vaccines
- whole killed organisms, modified bacterial toxins (proteins), or purified capsular
material (polysaccharides)
Pharm 428
September 14, 2004
e. conjugate vaccines
- portion of polysaccharide capsule conjugated to a protein carrier to enhance immune
response
- advantages over polysaccharide vaccines: can be used in children <2 yrs of age, better
response in immunocompromised individuals, longer lasting immunity
- example: Haemophilus influenzae type b (Hib)
f. adsorbed vaccines
- antigen or toxoid is fixed or adsorbed to the surface of aluminum phosphate, which
enhances the immune response
- examples: diphtheria, tetanus
g. herd immunity
- the point at which non-immune persons are protected from spread of a disease because
the majority of the population is immune
- prevents a disease from spreading throughout a population
- requires a high rate of immunity
4. Routine Immunizations (Ontario)
- schedules may differ slightly by province (different products used)
- “catch up” schedules in the CPS (purple pages)
DaPT = diphtheria, acellular pertussis, tetanus
Polio = inactivated polio vaccine
Hib = Haemophilus influenzae type b
MMR = measles, mumps, rubella
Td = tetanus, diphtheria (smaller diphtheria dose than preparations given to children < 7 years old)
Immunization Schedule for Infants and Children (Ontario)
Age
Vaccine
2 months
DaPT Polio and Hib* + pneumococcal conjugate + meningococcal conjugate
4 months
DaPT Polio and Hib* + pneumococcal conjugate + meningococcal conjugate
6 months
DaPT Polio and Hib* + pneumococcal conjugate + meningococcal conjugate
> 12 months
MMR + varicella§
12 – 15 months pneumococcal conjugate
18 months
DaPT Polio and Hib*
4 – 6 years
DaPT Polio + MMR
12 years
hepatitis B
14 – 16 years
Td or TdaP
every 10 years Td
yearly starting
influenza
at 6 months old
*
schedule for Pentacel® (Act-HiB® reconstituted with DaPT Polio)
§
must be given at the same visit, or > 1 month apart
Pharm 428
September 14, 2004
5. “New” Immunizations
a.
varicella vaccine (Varivax III®, Varilrix®)
- introduced in 1999
- complications of varicella infection: superinfection of lesions, necrotizing fasciitis,
cerebellar ataxia, encephalitis, pneumonia, congenital varicella syndrome (skin scarring,
hypoplastic limbs, neurologic defects)
- severe disease in immunocompromised individuals and adults
- 6-7 deaths per year; over 2000 hospitalizations (350 000 cases annually)
- mortality: infants 1/13 000 cases, children (ages 1-14) 2/100 000 cases
- efficacy of vaccine: 70 – 90% protection vs. varicella of any severity, and 95%
protection vs. severe disease
- studies from Japan indicate protection for at least 20 years
- side effects: local reaction (20%), low grade fever (15%)
mild rash (2-5 lesions) in 7% (rarely has virus been isolated)
- most rashes occurring within 2 weeks are due to wild-type virus
- spread of virus strain to others – v. rare (always with rash)
- NACI recommends for all persons older than 1 year who are susceptible
Age at immunization
12 months – 12 years
> 12 years
Varicella vaccine schedule
1 dose
2 doses given 4 – 8 weeks apart
b.
pneumococcal conjugate vaccine (Prevnar®)
- introduced June 2001
- leading cause of invasive bacterial infection in children: meningitis, pneumonia
- spread by nasal droplets (significant nasopharyngeal colonization)
- 15 deaths per year in children < 5yrs old
- side effects: irritability, fever, local reactions
- provides immunity against 7 of the 90 known serotypes of Streptococcus pneumoniae
- contains serotypes responsible for 80% of invasive disease and majority of penicillin
resistance
c.
meningococcal conjugate vaccine (Menjugate®, Meningitec® ,Neisvac-C®)
- introduced July 2001
- Neisseria meningitidis can cause rapid onset meningitis and/or septicemia
(meningococcemia)
- 300 cases per year (cyclical); peak incidence 6-24 months and 15-19 years
- spread by nasal droplets (10% nasopharyngeal colonization)
- fatal in 10% of cases; 10 – 20% with severe sequelae (deafness, disability)
- 13 serogroups
- B most common but poorly immunogenic (no vaccine available)
- C responsible for outbreaks (fatality rate 14%)
- vaccine contains serogroup C only
- side effects: irritability, local reactions, fever
Attached to your handout:
Schedule for rolling out provincial coverage for the new vaccines (Ontario Government document)
Pharm 428
September 14, 2004
6. Vaccine Administration
a. route: subcutaneous (SC) – MMR, varicella
intramuscular (IM) – most others, all adsorbed and conjugate vaccines
b. site: infants (2, 4, 6mo) – lateral thigh
children and adults – upper arm (deltoid)
7. Contraindications to Immunization
- anaphylactic reaction to a previous dose of the vaccine
- anaphylactic reaction to neomycin: MMR, varicella
- pregnancy: MMR, varicella
- severe immunodeficiency: MMR, varicella
- anaphylactic egg allergy: influenza vaccine
- not contraindications:
- mild to moderate local reactions to previous injection of the vaccine
- minor illness with or without fever (including common cold)
- convalescent phase of an acute illness
- concurrent antimicrobial therapy
- breastfeeding
- personal or family history of allergy
- MMR in egg allergy (immunization should take place where there are facilities to
manage anaphylaxis; patient must be monitored for 30 minutes post vaccination)
8. Adverse Effects
Adverse effects of vaccines have become a focus for public concern because
we are no longer familiar with the morbidity and mortality caused by the
diseases they prevent.
Attached to your handout:
“Comparison of effects of diseases and vaccines” (table from the Canadian Immunization Guide)
“Hot Shots” (article from Today’s Parent magazine)
- general side effects
- mild fever
- soreness at site of injection
- prevention
- acetaminophen 10-15mg/kg po 30 min before and q4h x 2-3 doses after immunization
- maximum 65mg/kg/day (15mg/kg/dose q6h or 10mg/kg/dose q4h) or 4g/day
- vaccine specific side effects
a. whole cell pertussis
febrile seizures and hypotonic-hyporesponsive episodes
incidence has declined considerably with the change to accelular pertussis
vaccine
Pharm 428
September 14, 2004
b.
-
varicella
mild rash (2-5 lesions) within 5-26 days of immunization (lesions appearing within
two weeks of immunization are usually due to wild type virus)
c.
-
oral polio (live vaccine)
very small risk of developing polio
risk has been eliminated with the change to inactivated polio vaccine
d.
-
influenza
oculo-respiratory syndrome (ORS): onset within 24 hours of bilateral red eyes,
respiratory symptoms, or facial edema
small risk of recurrence, but most recurrences are milder than initial episode
not a contraindication to receiving subsequent doses
e.
-
MMR
recent claim that MMR is associated with development of autism has not been
substantiated
initial study was small (12 patients) and highly flawed
retrospective studies from many countries have not found an association between
MMR and autism
Attached to your handout:
Medication forum: Does the MMR vaccine cause autism? (from the journal Pharmacy Practice)
- ADR reporting programs
- ADR reporting form can be found at the back of the CPS
- IMPACT: Immunization Monitoring Program – Active
- paediatric hospital based network, funded by Health Canada
- an active surveillance system which collects information on potential vaccine
related adverse reactions
9. Vaccine Storage
- vaccines are susceptible to degradation with heat or freezing
- must be transported and stored properly
- don’t store in the door of the refrigerator - this area is prone to temperature fluctuations
Additional reading:
Offit P, Quarles J, Gerber M, et al. Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or
Weaken the Infant’s Immune System? Pediatrics 2002;109: 124-29.
table on the back of this page: Canadian Immunization Guide (6th edition – 2002)
IPV = inactivated polio vaccine Hib = Haemophilus influenzae type b
DT = diphtheria, tetanus
SSPE = subacute sclerosing panencephalitis
DTaP = diphtheria, tetanus, acellular pertussis
CRS = congenital rubella syndrome