Supplement to Statistics Canada's Generic Privacy Impact Assessment related to Childhood National Immunization Coverage Survey

Date: October 2021

Program manager: Director, Centre for Social Data Integration and Development

Director General, Census Subject Matter, Social Insights, Integration and Innovation

Reference to Personal Information Bank (PIB):

Personal information collected through the Childhood National Immunization Coverage Survey is described in Statistics Canada's "Special Surveys" Personal Information Bank. The Personal Information Bank refers to information collected through Statistics Canada's ad hoc surveys, which do not form part of the regular survey taking activity of the Agency. They cover a variety of socio-economic topics including health, housing, labour market, education and literacy, as well as demographic data.

The "Special Surveys" Personal Information Bank (Bank number: StatCan PPU 016) is published on the Statistics Canada website under the latest Information about Programs and Information Holdings chapter.

Description of statistical activity:

Statistics Canada has conducted the Childhood National Immunization Coverage Survey (CNICS) every second year since 2011, under the authority of the Statistics Act, on behalf of the Public Health Agency of Canada (PHAC). The purpose of the Childhood National Immunization Coverage Survey (CNICS) is to collect information on immunization coverage for vaccines administered to children and pregnant women.

The survey is intended to:

  • Determine whether children and pregnant women are vaccinated in accordance with recommended immunization schedules for publicly funded vaccines;
  • Provide the World Health Organization and the Pan American Health Organization with estimates of national vaccine coverage for childhood vaccines such as those against measles, diphtheria, pertussis, tetanus and polio;
  • Provide information on parental and guardian knowledge and beliefs about vaccines.

CNICS is a voluntary survey, and for the 2021 cycle it collects information for children and youth aged 2, 7, 14 and 17 years old, and women who gave birth between September 1, 2020, and March 1, 2021, living in the 10 provinces and three territories. It excludes those residing on First Nations reserves and those living in institutions. Vaccination data is collected from the parent or guardian of the child, the biological mother (for vaccines received during pregnancy), the health care provider who administered the vaccines (where possible and when permission is provided for children aged 2, 7, 14 and 17 years) and from immunization registries in the provinces of Manitoba and PEI (when the parent or guardian has given permission). These sources of data are combined to create a full and complete picture of vaccine coverage.

Survey topics include vaccination status for childhood vaccines and vaccines administered during pregnancy, reason for non-vaccination, trusted sources of information for vaccination, and knowledge and beliefs about vaccines in general. For the 2021 cycle, questions were added to help understand the impact the COVID-19 pandemic has had on immunization and vaccine coverage for children and pregnant women. In addition, parents and guardians of children aged 2, 7, 14 and 17 years old are asked for their child's COVID-19 vaccination status and, if not vaccinated, they are asked their likelihood to vaccinate their child.

As was the case in 2019, for the 2021 cycle parents and guardians living in the provinces of PEI and Manitoba will have the opportunity to skip the detailed questions about their child's vaccination history, if they agree to share their child's identifiers with the respective provincial immunization registry. Statistics Canada has data sharing and data acquisition agreements in place with both PEI and Manitoba and as such, when permission is given by the parent or guardian, is able to retrieve the child's detailed vaccination data from the provincial registry. Statistics Canada does not have access to all of the immunization registry records for PEI or Manitoba, only those for the children included in CNICS and where the parent or guardian has given express permission. Statistics Canada continues to negotiate agreements with health authorities to access data from the other provincial and territorial registries. To reduce respondent burden further, record linkage to tax data is used to provide total household income for all respondents.

No other immediate requirements for linking results from the CNICS to other administrative datasets, surveys or the Census have been identified. However, given the importance of vaccinations for health and for social and economic recovery from the pandemic, there is a potential need to have data on vaccination impacts in the future. Any requirements for record linkage would follow established procedures for approval from the Chief Statistician and a record linkage rationale would be provided. If approved, all record linkages would be performed within Statistics Canada's secure Social Data Linkage Environment. Any data products released will be based on aggregated responses and processed to ensure that no individual can be identified.

CNICS is expected to continue to be collected every 2 years, and the data collected for CNICS 2021 will be of particular interest to measure the impact of COVID-19 on routine childhood vaccinations and vaccines administered during pregnancy.

Reason for supplement:

While the Generic Privacy Impact Assessment (PIA) addresses most of the privacy and security risks related to statistical activities conducted by Statistics Canada, this supplement describes additional measures being implemented due to the sensitivity of the information being collected. The CNICS will be collecting information on COVID-19 vaccination status and the impact the COVID-19 pandemic, which becomes more sensitive when collected alongside personal information, such as age, education level, ethnicity or other demographic characteristics. This SPIA describes how Statistics Canada has accounted for the unique impact to vulnerable populations when designing and conducting this survey, and integrates relevant principles of the Office of the Privacy Commissioner's Framework for the Government of Canada to Assess Privacy-Impactful Initiatives in Response to COVID-19. As is the case with all PIAs, Statistics Canada's privacy framework ensures that elements of privacy protection and privacy controls are documented and applied.

Necessity and Proportionality

The collection and use of personal information for the CNICS can be justified against Statistics Canada's Necessity and Proportionality Framework:

  1. Necessity:
    The main objectives of CNICS are to determine if children are being vaccinated in accordance with the recommended immunization schedules for publicly-funded vaccines and to measure to what degree recent public health recommendations are being adopted to increase vaccination against the flu and pertussis during pregnancy. CNICS results also allow Canada to meet its commitment to provide the World Health Organization and the Pan American Health Organization with estimates of national coverage for childhood vaccines such as measles, diphtheria, pertussis, tetanus and polio.
    Analysis of vaccination status, the knowledge and beliefs section together with demographic characteristics provides information to help health authorities focus vaccination campaigns for the under-vaccinated and vulnerable populations within our communities. CNICS results help inform the development of communication strategies and education outreach programs to address vaccination concerns. It is also important to note that CNICS targets the same age groups, provides the same demographic characteristics, and criteria to measure vaccine coverage for all provinces and territories, which allows for analysis and comparisons across jurisdictions. This information, together with the results on parents' knowledge and beliefs about vaccination, provides data that is not available from other sources such as provincial or territorial vaccine registries.
    For CNICS2021, a section was added to measure the impact of the COVID-19 pandemic on immunization for children and pregnant women, as well as COVID-19 vaccine uptake for vaccine eligible children. It is believed that the pandemic has had an impact on the routine immunization of children with recommended vaccines and on the vaccination of pregnant women. It is important to measure and understand this impact in order to address any delays and/or barriers. It is also important to understand how the pandemic may have influenced beliefs about vaccination in general.
    The personal identifiers for the children included in the survey (child's full name, date of birth, and provincial or territorial health card number) are collected in order to link with vaccine registry data and so reduce response burden now and in the future (once new agreements with provincial and territorial health authorities are signed). Personal identifiers are removed from the data file and stored separately and securely, once the linkage has been performed. When identifiers are provided and parent or guardian permission has been given, it allows Statistics Canada to use an administrative source of vaccination data rather than asking detailed questions of respondents, thereby decreasing burden. At the moment, this is only possible for respondents residing in the provinces of PEI and MB, with whom Statistics Canada has negotiated data sharing agreements to access vaccination registries. Statistics Canada is actively pursuing agreements with the other provinces and territories.
    The stakeholders for CNICS include: the Public Health Agency of Canada (who funds the survey program to measure vaccination coverage and reports results to the World Health Organization); provincial and territorial health authorities (who use the results to inform vaccination programs); healthcare providers and experts in epidemiology (for analysis and understanding of the factors influencing decisions around vaccination); and the Canadian public (to understand how well their children and pregnant women are protected against infectious diseases).
  2. Effectiveness - Working assumptions:
    The Public Health Agency of Canada has been sponsoring the Childhood National Immunization Coverage Survey (CNICS) every two years since 1994. Statistics Canada began conducting the survey on behalf of PHAC in 2011. The primary objective of the CNICS is to estimate immunization coverage rates for childhood vaccines in accordance with the national immunization recommendations.
    The CNICS collects immunization data for the following vaccinations: measles, mumps, rubella, varicella, polio, diphtheria, tetanus, pertussis, Haemophilus influenzae type b, for children ages 2 and 7; Rotavirus, pneumococcal, meningococcal and hepatitis B for 2-year old's; human papilloma virus (HPV) and hepatitis B for 14-year old's; meningococcal, and the tetanus-diphtheria-pertussis (Tdap) booster for 17-year old's. In 2019, the survey scope was expanded to collect immunization data from biological mothers of babies 0-6 months in order to estimate the rates of vaccination against pertussis and flu during pregnancy. New for the upcoming 2021 survey cycle, questions about the impact of COVID-19 pandemic on vaccination will be asked of parents of children (all age groups) as well as biological mothers of babies 0-6 months in age. Questions on COVID-19 vaccination uptake and likelihood of vaccination will be asked of parents of children aged 2, 7, 14 and 17 years.
    All Statistics Canada directives and policies for the development, collection, and dissemination of surveys and their results are followed. Survey responses will not be attached to respondents' addresses or phone numbers. The 2021 data will be representative of the Canadian population at a national level, and may be broken down (disaggregated) at the provincial and territorial level for pregnant women and children aged 2 years old. More detailed results are needed for pregnant women because the pertussis and flu vaccines have only recently been recommended for women during pregnancy to protect their child in the first few months of life. Provincial and territorial level results for 2 year old's have been collected every 2nd cycle of CNICS to allow for accurate and detailed tracking of progress towards childhood vaccination goals. In addition, childhood vaccine coverage results from each cycle of CNICS are also reported to the WHO and Pan-American HO. When the quality of the estimates is sufficient and the identity of respondents is protected, disaggregation by other demographic characteristics (such as ethnicity or immigration status) may be possible.
    The CNICS asks parents and guardians of children to provide personal identifiers for the selected child in order to perform record linkages with provincial and territorial immunization registries and reduce response burden now (for residents of PEI and Manitoba who have sharing agreements in place) and in the future (for residents of provinces and territories with whom Statistics Canada is pursuing data sharing agreements). These identifiers include the child's name, date of birth and their provincial or territorial health card number and are used to link to the child's detailed vaccine history housed within the immunization registries when the parent or guardian has given permission and when sharing agreements have been negotiated with the appropriate health authority. All parents are asked about sharing data for the purposes of record linkage with registry data. If there are no data sharing agreements currently in place for the respective province or territory, the parents permission would be required to evaluate the coverage and quality of registry data compared to survey data, once agreements have been approved and signed. The identifiers are not retained in the final survey data results.
  3. Proportionality:
    CNICS has been collecting information on childhood vaccination for many years and with the advent of the pandemic and subsequent development of COVID-19 vaccines, it was deemed logical and appropriate that it also collects information on the vaccination status of children eligible for vaccination against COVID-19 and the likelihood of non-vaccinated children to be vaccinated in the future. This information may be considered sensitive, however after careful consideration and consultations with partners, the benefits of having results that measure coverage and risk to children's health during the pandemic were sufficient to warrant the added burden and impact on the privacy of respondents. The questions are short and simple, re-using wording from other CNICS questions, and adapting questions from other surveys such as the COVID-19 Vaccination Coverage Survey (CVCS). The new questions were reviewed and assessed by experts from the Questionnaire Design and Resource Centre at Statistics Canada to ensure they are clear, concise and coherent.
    All the data to be collected are required for the purpose of the survey as described above. Careful consideration was made for each question and response category to ensure that it would measure the research questions and help inform future decisions about childhood and pregnant women vaccine programs and specifically those related to COVID-19 vaccination. Experts at PHAC worked closely with Statistics Canada to determine the content of the survey questions, including the demographic information that will help in the analysis of the survey results. Information such as the respondent's age, gender, ethnicity and education level, all have the potential to affect a person's access to healthcare and their beliefs about vaccination. It is important to include these factors, where possible, when analyzing survey results and progress towards vaccination coverage goals.
    The 2021 sampling strategy was designed to provide results at the national level for all age groups (2, 7, 14 and 17 years) including pregnant women, and at the provincial and territorial level for children aged 2 years old and for pregnant women (except in the territory of Nunavut). Without substantially increasing the sample size, it is not possible to ensure that the survey would produce reliable results for smaller population groups, such as some of the more vulnerable populations.
    The sample size is 19,494 and can be broken down by age group as follows:
    Age group Sample size
    2 years 9,274
    7 years 1,044
    14 (male) 775
    14 (female) 774
    17 846
    Pregnant women 6,781
    Total 19,494
    The sample of pregnant women in Nunavut was reduced in order to alleviate burden which has been an emerging issue for the territory with a small and dispersed population, especially during the pandemic. The Northern Governance Committee at Statistics Canada was consulted and involved in determining the sampling strategy for the north and it was decided that, given the reporting obligations to WHO, collection efforts will focus on obtaining meaningful and publishable results for 2 year old's in the territory of Nunavut. The Centre for Indigenous Statistics and Partnerships also provided input to ensure appropriate engagement, and consideration for the interests of Indigenous peoples.
    Statistics Canada directives and policies with respect to data collection and publication will be followed to ensure the confidentiality of the data. Individual responses will be grouped with those of others when reporting results. Individual responses and results for very small groups will not be published. The grouping of results will make it impossible to identify individual respondents and reduces any potential impact on vulnerable populations or subsets of populations. Survey results will be made available in the Federal Research Data Centre (FRDC) but no personal identifiers will be included. PHAC experts, who have been deemed Statistics Canada employees, will have access to this micro data file to assist them with data validation and the analysis of survey results. Only aggregate/grouped data that has been vetted for confidentiality will be allowed to leave the FRDC. All data results are managed in accordance with Statistics Canada's security and confidentiality requirements.
    The survey findings will support decision-making at all levels of government concerned with ensuring the health and safety of children in Canada by protecting them from infectious diseases such as COVID-19. These benefits are believed to be proportional to the invasion of privacy and associated risks.
  4. Alternatives:
    The CNICS has been negotiating data sharing agreements with provincial and territorial health authorities to have access to children's detailed vaccination histories since 2017. The project has progressed with agreements now in place for Manitoba, Prince Edward Island and the Northwest Territories (with whom it is not yet possible to access the data because of technical reasons), but there is still a long way to go before it would be possible to use registry provided vaccine data instead of parent or healthcare practitioner provided information for all provinces and territories. As a result, the only way to obtain a complete and comprehensive picture of childhood vaccine coverage across Canada is through the CNICS. As a survey collecting information on childhood vaccines, it makes sense that CNICS should also incorporate questions on COVID-19 vaccination as children become eligible. There is no other survey that is as well placed to ask these questions about the COVID-19 vaccination status of children and the likelihood they will be vaccinated. Many Statistics Canada surveys, such as the Canadian Community Health Survey, the Canadian COVID-19 Antibody and Health Survey, the COVID-19 Vaccination Coverage Survey and the Canadian Perspectives Survey Series, collect information on COVID-19 vaccine status and willingness, but don't have the ability to easily focus their efforts to capture data for children's vaccination against COVID-19.
    The CNICS provides up-to-date and comparable results for the provinces and territories. It also provides a detailed breakdown of why people are choosing not to get their children vaccinated and allows health authorities to address concerns and promote childhood vaccine uptake.

Mitigation factors:

Some questions contained in the CNICS may be considered sensitive as they relate to parents' and guardians' views on vaccination against COVID-19, a complex and often difficult topic to broach during the pandemic. However, the overall risk of harm to the survey respondents has been deemed manageable with existing Statistics Canada safeguards that are described in Statistics Canada's Generic Privacy Impact Assessment, as well as with the following measures:


Prior to the survey, respondents will be informed of the survey purpose, allowing them to decide whether they wish to participate. The survey purpose reads:

For parents/guardians of children aged 2, 7, 14 and 17 years:

The information collected by the Childhood National Immunization Coverage Survey (CNICS) measures the proportion of Canadian children who are vaccinated against certain diseases. It also asks parents and guardians about their knowledge of vaccines and the diseases they are meant to prevent, as well as their opinions about vaccines.

The data will be used to:

  • provide childhood vaccine coverage rates across Canada
  • understand parents' and guardians' knowledge and beliefs about vaccination
  • help improve public health programs.

For pregnant women:

The Childhood National Immunization Coverage Survey (CNICS) collects data on vaccines received by mothers during their pregnancy, and on mothers' knowledge and perceptions about vaccination during pregnancy.

The data will be used to:

  • measure the percentage of Canadian pregnant women who were vaccinated for whooping cough and influenza during their pregnancy
  • understand mothers' knowledge and beliefs about vaccination
  • help improve prenatal health programs.

This information will be provided to survey participants via invitation and reminder letters. It will also be reiterated at the beginning of the questionnaire. Respondents will also be informed in the invitation letter, reminder letters, and in the questionnaire itself, that their participation is voluntary before being asked any questions. Information about the survey, as well as the survey questionnaire, will also be available on Statistics Canada's website.


Variables that directly identify respondents or their children will be separated from the data files in the first stage of data processing and placed in a secure location with controlled access. Variables that might indirectly identify respondents are examined and modified as necessary in order to protect the privacy and confidentiality of respondents. Individual responses will be grouped with those of others when reporting results. Individual responses and results for very small groups will never be published or shared with government departments or agencies. Careful analysis of the data will be performed prior to the publication and sharing of aggregate data to ensure that marginalized and vulnerable communities are not disproportionally impacted.


This assessment concludes that with the existing Statistics Canada safeguards and additional mitigation factors listed above, any remaining risks are such that Statistics Canada is prepared to accept and manage the risk.

Formal approval:

This Supplementary Privacy Impact Assessment has been reviewed and recommended for approval by Statistics Canada's Chief Privacy Officer, Director General for Modern Statistical Methods and Data Science, and Assistant Chief Statistician for Social, Health and Labour Statistics.

Pierre Desrochers
Chief Privacy Officer
Date: October 28, 2021

Eric Rancourt
Director General,
Modern Statistical Methods and Data Science
Date: November 4, 2021

Lynn Barr-Telford
Assistant Chief Statistician,
Social, Health and Labour Statistics
Date: November 5, 2021

The Chief Statistician of Canada has the authority for section 10 of the Privacy Act for Statistics Canada, and is responsible for the Agency's operations, including the program area mentioned in this Supplementary Privacy Impact Assessment.

This Privacy Impact Assessment has been approved by the Chief Statistician of Canada.

Anil Arora
Chief Statistician of Canada

Date modified: