Monitoring trends in coverage is important to identify the potential for transmission or outbreaks of vaccine-preventable diseases. When coverage rates drop in a population, the chances of a vaccine-preventable disease outbreak occurring in that population increase.
Coverage is assessed in order to:
- Measure how many people are protected against vaccine-preventable diseases within the overall population
- Identify specific populations (people living in certain communities) that have low vaccine coverage to explore reasons for low coverage and find ways to increase coverage
Monitoring also helps public health in resource allocation - for example, where to improve access to immunization services or public education efforts.
In BC, immunization coverage is routinely measured for uptake of:
- Pertussis vaccine in the first year of life
- Routine childhood immunizations at the second birthday
- Routine childhood immunizations among school-age children
- Influenza vaccine among acute care hospital staff and long-term care facility staff and residents
A routine
immunization schedule is in place in BC. Through this schedule, infants and children in BC are offered vaccines that protect against many different diseases.
Most infants and toddlers are immunized either by public health nurses at their local health unit or by their family physicians or nurse practitioner. While immunization records for most children in BC are kept in the Provincial Immunization Registry (PIR), some immunizations may be missing if not reported to public health, such as those received outside of BC. PIR records are used to measure immunization coverage for children living in Fraser Health, Interior Health, Island Health, and Northern Health. In Vancouver Coastal Health, immunization coverage for school-aged children is measured using PIR records, while coverage for early childhood is assessed by periodic surveys.
