OTTAWA — The Public Health Agency of Canada says it hopes to keep the number of wasted doses of COVID-19 vaccines in Canada under five per cent.
That would amount to 3.7 million of the 73.7 million vaccines that have been distributed to provinces and territories, used by the federal government or held in the central vaccine inventory as of Nov. 18.
While some vaccine waste is unavoidable, the federal, provincial and territorial governments aim to keep vaccine wastage as low as possible.
The Public Health Agency of Canada would not release the total number of wasted doses to date, but a Canadian Press survey of provincial governments shows an average of about 2.6 per cent of distributed doses in responding jurisdictions have been discarded.
"An estimate of 2.6 per cent of reported waste is within the planning parameters of five per cent that we have been using given the nature of the product (biological) and the management to date," a spokesperson for the agency wrote in a statement.
According to the informal survey conducted by The Canadian Press, vaccine wastage rates vary widely across the country, from 10.6 per cent in Nunavut to 0.3 per cent in Nova Scotia.
Several provinces did not respond to The Canadian Press in time for publication, while others released only the number of doses that have expired before use.
Managing a scarce and precious perishable commodity like COVID-19 vaccines is a complex matter that poses different challenges across the country.
Provinces gave various reasons for wasted doses. They included dropped vials or syringes, defective syringes or damaged vials, poor dose management and expired doses. Many could not provide a full breakdown.
In Nunavut for example, where smaller communities are often spread far apart, it may be difficult to use up entire vials of vaccine.
For years, health systems around the world have struggled to limit the wastage of vaccines as much as possible.
It's nearly impossible to declare an acceptable level of vaccine waste, according to Guidelines published by the World Health Organization in 2005.
That year the WHO reported 50 per cent of vaccines were wasted worldwide.
But it all depends on the local situation.
"For example, remote services have to open more vials … than urban services, and as a result higher wastage rates are expected in rural areas," the guidelines state.
A 1995 study found vaccine wastage accounted for 3.3 per cent of total regional vaccine budgets in Canada, while a study of 57 immunization programs in the United States found about 2.6 per cent of vaccines were wasted in 1999.
But vaccine wastage in unopened vials that simply expire is unacceptable and should be minimized, according to the WHO.
Of provinces that provided the information to The Canadian Press, 0.45 per cent of their vaccines had to be tossed after they expired — about 120,578 doses.
Vaccine coverage is also a major factor in wastage. Typically, the more people who are already vaccinated, the more waste that occurs, the WHO's guidelines state.
The government has warned that as demand for COVID-19 vaccines slows down, there could be more wastage because new vials may have to be opened without every dose making it into someone's arm.
"As the proportion of eligible Canadians vaccinated continues to increase and demand goes down, it is possible that some increased wastage will be observed due to multi-dose vial presentations, fewer opportunities for use, and limited shelf-life of the product once punctured," the spokesperson for PHAC said.
The government says it works with provinces and territories to make sure procurement of new vaccines align with their needs and helps facilitate the transfer of doses between provinces to minimize waste.
This report by The Canadian Press was first published Nov. 22, 2021.
Laura Osman, The Canadian Press