Vulnerable and Hard-to-reach Populations COVID-19 Immunization Coverage Survey (VHCICS)

Methodological Report

Prepared for the Public Health Agency of Canada
Supplier name: Advanis Inc.
Contract number:6D142-224912
Contract value: $296,072.43 (including HST)
Award date: October 7, 2022
Delivery date: July 24, 2023

Registration number: POR 058-22
For more information on this report, please contact Health Canada at:

Ce rapport est aussi disponible en français.

Table of contents

Vulnerable and Hard-to-reach Populations COVID-19 Immunization Coverage Survey

Methodological Report

Prepared for the Public Health Agency of Canada
Supplier Name: Advanis Inc.
July 2023

This report presents the methodological details for the Vulnerable and Hard-to-reach Populations COVID-19 Immunization Coverage Survey (VHCICS) conducted by Advanis Inc. on behalf of the Public Health Agency of Canada (PHAC). The survey was administered among 5,703 members of the adult Canadian general public, between January 9 and February 23, 2023.

Ce rapport est aussi disponible en français sous le titre: Enquête sur la couverture vaccinale contre la COVID-19 auprès des populations vulnérables et difficiles à atteindre

This publication may be reproduced for non-commercial purposes only. Prior written permission must be obtained from the Public Health Agency of Canada. For more information on this report, please contact:

Health Canada, CPAB
200 Eglantine Driveway, Tunney's Pasture
Jeanne Mance Building, AL 1915C
Ottawa, Ontario K1A 0K9

Catalogue Number:
International Standard Book Number (ISBN):

Related publications (registration number: 58-22):
Catalogue number: H14-440/2023F-PDF (Rapport methodologique, Francais)
International Standard Book Number (ISBN): 978-0-660-49118-9 (Francais)

©His Majesty the King in right of Canada, as represented by the Public Health Agency of Canada, 2023

1. Executive Summary

1.1 Background

Surveillance data suggests that vaccine coverage is uneven across Canada. Furthermore, results from existing surveillance tools suggest that some population subgroups are under-surveyed, which results in insufficient data regarding immunization status, knowledge, attitudes, and behaviours towards vaccination within these specific groups. In turn, this hinders core immunization functions including COVID-19 vaccine surveillance, vaccine confidence, available data, policy, public health guidance, and knowledge mobilization activities.

In the effort of addressing COVID-19 coverage gaps relating to vulnerable and hard-to-reach populations, the Public Health Agency of Canada (PHAC) developed this new surveillance tool, the Vulnerable and Hard-to-reach Populations COVID-19 Immunization Coverage Survey (VHCICS).

The purpose of the VHCICS is to provide information that is currently unavailable regarding COVID-19 immunization coverage and uptake in select vulnerable and hard-to-reach populations.

New surveillance tools are needed to address data coverage gaps identified for these sub-populations and to inform public health vaccination programs and initiatives. It will also inform decisions on prioritizing investments and crucial information funneled through PHAC, as well as federal, provincial, territorial and private partners.

1.2 Objectives

The primary objective of this surveillance project was to establish a surveillance tool to gain a better understanding of COVID-19 coverage-related information in select vulnerable and hard-to-reach populations.

Specifically, this survey aimed to collect information on:

The second survey objective was to document the socioeconomic, cognitive, and motivational factors associated with low uptake of the COVID-19 vaccine in eleven (11) vulnerable and hard-to-reach populations in relation to a general population benchmark sample.

1.3 Methodology

Data collection started on January 9, 2023, and ended on February 23, 2023, and was conducted by Advanis.

Advanis first focused on a benchmark survey that was a probability-based survey of 1,005 Canadians aged 18 or older using Advanis' General Population Representative Sample (GPRS) sample in a multi-phase sampling approach. This approach involves collecting data from randomly selected sample units (GPRS), and then collecting more data from a randomly selected subsample1.

Advanis then used the same core questions in the questionnaire administered to the general population to survey 11 specialized, vulnerable and hard-to-reach populations, each with a couple of variations according to the target population. Overall, a sample of 5,703 Canadians aged 18 or older was reached using Advanis' GPRS sample. For the specialized groups, recruitment was completed using targeting information Advanis had on profile within the GPRS database to ensure quota minimums were met. Targeting was possible for those in groups A and B, but group C was based on natural fallout of the sample. The results can be extrapolated to general population and to the targeted A and B subpopulations.

The 11 specialized vulnerable and hard-to-reach populations included:

Participants pulled from Advanis' GPRS sample were recruited by cell phone and were invited to participate in a Web survey. Those who agreed to participate received an email or SMS inviting them to take part in the survey.

Survey results were weighted by nested data obtained from Statistics Canada from the 2021 census. The weighting variables included status on gender, education, income, age, population center, visible minority, recent immigrant and Indigenous. The results for 2023 are based on responses from 5,703 Canadians across all provinces and territories. Recruitment ensured quotas were reached for key sub-populations to ensure statistical relevance and representativeness.

1.4 Contract Value

The contract value for this survey was $296,072.43 (including HST).

1.5 Political Neutrality Requirement

I hereby certify as a Senior Officer of Advanis that the deliverables fully comply with the Government of Canada political neutrality requirements outlined in the Communications Policy of the Government of Canada and Procedures for Planning and Contracting Public Opinion Research.

Specifically, the deliverables do not contain any reference to electoral voting intentions, political party preferences, standings with the electorate, or ratings of the performance of a political party or its leader.

Nicolas Toutant
Vice President, Research and Evaluation

1 Statistics Canada (2021). Statistics: Power from Data! – Probability Sampling – Multi-Phase Sampling Approach.