Public Health & the Canadian Immunization System Flashcards
What is the difference between Public Health and
Population Health?
Public Health
The organized efforts of society to
keep people healthy and prevent
injury, illness and premature death.
It is a combination of programs,
services and policies that protect
and promote the health of all
Canadians.
Population health is an approach to
health that aims to improve the
health of the entire population and
to reduce health inequities among
population groups. In order to reach
these objectives, it looks at and acts
upon the broad range of factors and
conditions that have a strong
influence on our health.
Pharmacists’ Roles
in Public Health and
Emergency
Preparedness
Immunizations – routine and
additional immunizations in
emergencies
Ensuring access to
medication and supplies in
emergencies
Health promotion
Health education
Point of care testing
Screening
Why Does Mortality Differ Across Countries?
- Differences in the number of people tested: With more
testing, more people with milder cases are identified. This
lowers the case-fatality ratio. - Demographics: For example, mortality tends to be higher in
older populations. - Cultural Differences: For example, housing differences and
extended family relations - Characteristics of the healthcare system: For example,
mortality may rise as hospitals become overwhelmed and
have fewer resources. - Other factors, many of which remain unknown
Why is SARS–COV-2 so Concerning?
▪ No inherent population protection from the virus means rapid spread and a rise in
cases
▪ No vaccine or treatments to control the spread
▪ Widespread uncontrolled infection leads to variants
▪ High R0 means rapid spread through the population
▪ Rapid spread means a huge rise in hospitalization rates
▪ Healthcare system becomes overwhelmed and is not able to handle the strain of the
infection as well as regular caseloads
▪ Even 1% of the population of the world is 80 million people (Australia, Canada, and
Belgium
What is R0?
R0 or “R-naught” is the reproductive number
of a disease. Essentially it is a measure of
how many people one sick person can infect
if there are no control measures in an
unimmunized population. (control measures
depend on how a disease is spread)
▪ If a disease has an R0 < 1 then it will fade
over time as it takes more than 1 sick
person to infect another.
▪ An R0 of 1 would keep the same number
sick all the time.
▪ An R0 of > 1 means it will spread and the
higher the number the faster the spread.
measles 16.0
Vaccination Benefits
▪ They are also one of the most important
accomplishments of Public Health.
▪ Immunization directly protects
individuals who receive the vaccine
and indirectly protects the community
▪ Has led to the elimination (smallpox,
polio), containment, and control of
diseases
▪ Vaccination programs are needed to
prevent re-emergence of disease
What is Herd Immunity
When sufficient proportion of a
population is immune to an
infectious disease (through
vaccination and/or prior illness) to
make its sustained spread from
person to person unlikely
▪ Has been used to establish critical
vaccination level or threshold
▪ Challenge – vaccination coverage
difference between groups in a
population
▪ Herd immunity threshold is defined by
1-(1/R0)
▪ Herd immunity Targets
▪ Influenza >35%
▪ Ebola > 50%
▪ Mumps > 78%
▪ Rubella/Small pox > 83%
▪ Measles > 94%
▪ Covid > 60%
▪ Omicron >70% to 88%
▪ BA.5/5 >95%
The more easily infection can spread the
greater the proportion of the population
that must be immune to block sustained
transmission.
Vaccination Goals
▪ Established Nationally and
Provincially
▪ National (Canadian) Vaccination
Goals by 2025
* Infants and children – achieve 95%
coverage of childhood vaccines by 2 years
and 7 years of age
* Adolescents – achieve 90% coverage by
17 years (e.g. meningococcal, HBV, HPV,
Tdap)
* Adults – achieve 80% coverage in adults ≥
65 years (pneumococcal)
* Seasonal influenza - achieve 80%
coverage in adults ≥ 65 years, those 19-64
years with chronic health conditions, and
healthcare professionals
none of the goals have been met
Vaccination Uptake
what ppl think and feel + social processes
= motivation
practical issues
vaccination
Vaccine Development and Delivery in Canada
lab studies
pre-clinical
clinical phase 1
clincal phase 2
clinical phase 3
How do We Monitor Vaccine Safety
▪ CAEFISS is managed by PHAC and is unique in that it includes both passive and active surveillance.
▪ Passive
▪ Canadian Adverse Events Following Immunization Surveillance System (CAEFISS)
▪ Active
▪ Immunization Monitoring Program ACTive (IMPACT)
What is an Adverse Event Following Immunization
* An AEFI is defined as an unfavourable h ealthoccurrence experienced by a patient that:
* Follows immunization
* Cannot be attributed to a pre-existing condition and
* Meets one or more of the following as determined by a health practitioner:
* A life-threatening health occurrence that requires hospitalization or urgent medical attention.
* The health occurrence is unusual or unexpected that:
* Has not previously been identified; or
* Has been previously identified but has increased frequency
* The health occurrence cannot be explained by the patient’s medical history, recent disease or illness or consumption of medication.
How do We Monitor Vaccine Safety
▪ CAEFISS is managed by PHAC and is unique in that it includes both passive and active surveillance.
▪ Passive
▪ Canadian Adverse Events Following Immunization Surveillance System (CAEFISS)
▪ Active
▪ Immunization Monitoring Program ACTive (IMPACT)
What is an Adverse Event Following Immunization
* An AEFI is defined as an unfavourable h ealthoccurrence experienced by a patient that:
* Follows immunization
* Cannot be attributed to a pre-existing condition and
* Meets one or more of the following as determined by a health practitioner:
* A life-threatening health occurrence that requires hospitalization or urgent medical attention.
* The health occurrence is unusual or unexpected that:
* Has not previously been identified; or
* Has been previously identified but has increased frequency
* The health occurrence cannot be explained by the patient’s medical history, recent disease or illness or consumption of medication.
Who Makes Recommendations for Vaccine Use?
National Advisory Committee on Immunization (NACI)
* Falls under the Public Health Agency of Canada
* Comprised of recognized experts - paediatrics, infectious diseases,
immunology, pharmacy, nursing, epidemiology,
Pharmacoeconomics, social science and public health
* Provides the scientific perspective
* Makes recommendations for the use of vaccines independent of
cost considerations only based on evidence and efficacy
Who Makes Recommendations for Immunization
Program Planning?
- Canadian Immunization Committee (CIC)
- Comprised of federal/provincial/territorial public health officials
- Review and provide recommendations on immunization program planning (e.g. cost-analysis
of vaccines vs overall benefit to society) - Established to develop national goals and targets
Immunization Programs in Alberta
role of AACI
ISC
Alberta Advisory Committee on Immunization (AACI):
* reviews vaccine recommendations
* provides scientific expert recommendations to Alberta Health for new or enhanced
immunization programs
Immunization Steering Committee (ISC):
* develop policies and high-level program guidelines
Decisions are made based on a variety of criteria including a cost benefit analysis to
determine if a vaccine will be publicly funded.
