What Does Immunization Coverage Mean?
Immunization coverage can be defined as the percent of people who receive one or more vaccine(s) of interest in relation to the overall population. For example, immunization coverage for influenza among people aged 65 years and over is calculated as:
| People aged 65 years and over receiving influenza vaccine in the previous season |
x 100% |
|
Total population aged 65 years and over |
The BC Centre for Disease Control works with the province’s regional health authorities to assess immunization coverage in order to:
- Measure how many people are protected against vaccine-preventable diseases within the overall population
- Identify ‘populations’ (e.g. people living in certain communities), that have low vaccine coverage in order to explore reasons for low coverage
Immunization Coverage Measures
In British Columbia, immunization coverage is routinely measured for:
Why is monitoring coverage important?
Monitoring trends in coverage is important in order to identify the potential for outbreaks of vaccine-preventable diseases (i.e., when coverage rates drop in a population, that population has increased chances of having a vaccine-preventable disease outbreak). In addition, monitoring also guides the BCCDC to recommend where public health should allocate its resources, such as to improving access to immunization services or to public education efforts.