What Does Immunizaton Coverage Mean?
Immunization coverage can be defined as the percentage of people who receive one or more vaccines 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 province’s five 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:
Immunization Targets
There are national and provincial targets for immunization rates against most vaccine preventable diseases. Declines in immunization coverage in other countries have resulted in some diseases reappearing, such as measles and whooping cough (pertussis).
Why is monitoring coverage important?
While immunization rates have been increasing in BC in recent years, monitoring trends in coverage is important in recognizing the potential for outbreaks of disease. 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.