Background In 2019, the World Health Organization (WHO) designated vaccine hesitancy as one of the ten leading threats to global health. Vaccine hesitancy exists when vaccination services are available and accessible, but vaccine uptake is lower than anticipated. It is often attributed to lack of trust in vaccine safety and effectiveness, or low level of concern about the risk of many vaccine-preventable diseases. This study aimed to examine the sociodemographic factors associated with parental vaccine hesitancy and vaccine refusal in Canada using data from the 2017 Childhood National Immunization Coverage Survey (CNICS). Method The 2017 CNICS was a cross-sectional and nationally representative survey to estimate national vaccine uptake and to collect information about parents’ Knowledge, Attitudes and Beliefs (KAB) regarding vaccination. Using the KAB questions, parental vaccine hesitancy (i.e., parental hesitation, delay or refusal of at least one recommended vaccination) and refusal (i.e., unvaccinated children) by sociodemographic factors was estimated using weighted prevalence proportions. A multinomial logistic regression model was fitted to examine associations between parental vaccine hesitancy or refusal and sociodemographic factors among parents of two-year-old children in Canada. Adjusted odds ratios (aOR) of being vaccine-hesitant or vaccine-refusing versus being non-vaccine-hesitant were generated. Results Both unadjusted and adjusted logistic regressions models showed that parents with lower household income (aOR 1.7, 95% CI 1.2–2.5), and those with a higher number of children in the household (aOR 2.2, 95% CI 1.4–3.5) had higher vaccine hesitancy. Conversely, lower vaccine hesitancy was observed among non-immigrant parents (aOR 0.4, 95% CI 0.3–0.6). In addition, lower household income (aOR 4.0, 95% CI 1.3–12.9), and higher number of children in the household (aOR 6.9, 95% CI 2.1–22.9) were significantly associated with parental vaccine refusal. Regional variations were also observed. Conclusion Several sociodemographic determinants are associated with parental vaccine hesitancy and refusal. The findings of the study could help public health officials and policymakers to develop and implement targeted interventions to improve childhood vaccination programs.

INTRODUCTION:Disparities in COVID-19 vaccination coverage emerged during the vaccination campaign. This study aimed to assess whether inequalities in COVID-19 vaccination coverage in Canada persisted or resolved throughout the vaccine rollout. METHODS:Using data from the Canadian Community Health Survey, the analysis included people 18 and older from all ten provinces. Vaccination coverage for at least one dose of a COVID-19 vaccine was determined in three periods: June 2021-February 2022 (n = 28,182), February-June 2022 (n = 25,742), and July-December 2022 (n = 23,119). Statistically significant gaps across groups were assessed using non-overlapping 95 % confidence intervals (CI). RESULTS:In June 2021-February 2022, coverage for at least one dose (95 % CI) was 85.5 % (79.0-90.3) for off-reserve First Nations people, 85.7 % (79.6-90.1) for Métis people, 79.6 % (72.1-85.4) for Black people, 83.0 % (72.9-89.9) for Arab people, and 92.9 % (92.3-93.5) for White people. By July-December 2022, coverage was 87.4 % (80.2-92.3), 90.5 % (85.5-93.8), 92.1 % (87.2-95.2), 95.6 % (90.6-98.0), and 95.1 % (94.5-95.6), respectively, in the same populations. The gap between off-reserve First Nations and White people remained significant, at 7.4 percentage points (pp.) in the first period and 7.6 pp. in the third period. As for Métis and White people, the gap decreased from 7.3 pp. to 4.6 pp. In the first period, the gap compared to White people was 13.4 pp. for Black people and 9.9 pp. for Arab people, and resolved in the third period. Significant gaps also remained across age groups, levels of educational attainment, household income, for those residing in rural areas, those living with children under 12 years old, and those without a regular healthcare provider. CONCLUSION:Despite efforts to address them, several inequalities persisted throughout the vaccine rollout, underscoring the need for refined strategies to reach all population segments. As Canadian vaccination registries do not collect sociodemographic data beyond date of birth, sex and place of residence, survey data is needed to measure these disparities.

A decline in routine vaccination coverage in children has been observed after the onset of the COVID-19 pandemic, but it is unclear whether these declines were sustained over time. This analysis assessed changes in vaccination coverage at ages 2 and 7 years for routinely administered vaccinations before, during, and after the COVID-19 pandemic. Vaccination coverage was measured using yearly data from the Standardized Reporting on Vaccination (STARVAX) surveillance system between December 31, 2019, and December 31, 2023. Four provinces (Alberta, Saskatchewan, Manitoba, and New Brunswick) and one territory (Yukon) produced reports from their immunization registries and provided the Public Health Agency of Canada with the numbers of vaccinated 2-year-old and 7-year-old children. Population estimates from Statistics Canada and the Yukon Bureau of Statistics were used as the denominators. There was a decline in vaccination coverage in 2023 compared to 2019. In 2-year-olds, coverage for one dose of the measles, mumps, and rubella (MMR) vaccine and four doses of the diphtheria, tetanus, and acellular pertussis (DTaP) vaccine decreased from 89.5

Abstract Background Vaccination prevents seasonal influenza and its complications, particularly among high-risk populations. The COVID-19 pandemic has been reported to impact healthcare behaviors and vaccination patterns. This study aims to assess influenza vaccination coverage and changes in vaccination settings among Canadian adults from the 2018–2019 to the 2023–2024 seasons. Method We conducted a retrospective analysis of data from multiple cycles of the Seasonal Influenza Vaccination Coverage Survey (SIVCS). Vaccination coverage was examined across different seasons, stratified by population groups. Odds ratios (ORs) were calculated to compare vaccination likelihoods across seasons, with 2018–2019 serving as the reference. Chi-square tests were applied to determine whether there were significant differences in the place of vaccination since the pre-pandemic season. Results When comparing vaccine uptake before, during and after the COVID-19 pandemic, we observed a temporary coverage decline in 2021–2022 season (OR = 0.882, 95% CI = 0.787–0.988) compared to the pre-pandemic season in 2018–2019. By the 2022–2023 and 2023–2024 seasons, vaccination coverage returned to pre-pandemic levels. Coverage among adults aged 18–64 without chronic medical condition consistently remained lower than in other groups. The places of vaccination shifted markedly, with pharmacies becoming the predominant site, increasing from 35.4% in 2018–2019 to 57.4% in 2023–2024, while doctor’s offices saw a decline from 32.7 to 15.2% over the same period. Conclusion Our findings highlight the transient effect of the pandemic on flu vaccine uptake in Canada. The increasing use of pharmacies for vaccinations underscores the importance of accessible and convenient vaccination sites. Future efforts should focus on maintaining and improving vaccination coverage through diverse and adaptable vaccination settings.

The objective of this study was to identify the determinants of influenza non-vaccination during pregnancy in Canada. Biological mothers of children born between December 2018 and March 2019 were surveyed about vaccinations they had received during pregnancy, reasons for non-vaccination, obstetrical history, and demographics. Simple and multiple logistic regression models were used to measure associations between various sociodemographic factors as well as obstetrical history, and non-vaccination against influenza. We analyzed data from 2361 mothers. Factors associated with non-vaccination included being followed during pregnancy by a midwife compared to by an obstetrician-gynecologist (OR 2.02; 95

Background: Racial and ethnic disparities in COVID-19 vaccination coverage have been observed in Canada and in other countries. We aimed to compare vaccination coverage for at least 1 dose of a COVID-19 vaccine between First Nations people living off reserve and Métis, Black, Arab, Chinese, South Asian and White people. Methods: We used data collected between June 2021 and June 2022 by Statistics Canada’s Canadian Community Health Survey, a large, nationally representative cross-sectional study. The analysis included 64 722 participants aged 18 years or older from the 10 provinces. We used a multiple logistic regression model to determine associations between vaccination status and race, controlling for collection period, region of residence, age, gender and education. Results: Nonvaccination against COVID-19 was more frequent in off-reserve First Nations people (adjusted odds ratio [OR] 1.8, 95% confidence interval [CI] 1.2–2.7) and Black people (adjusted OR 1.7, 95% CI 1.1–2.6), and less frequent among South Asian people (adjusted OR 0.3, 95% CI 0.1–0.7) compared to White people. Interpretation: This analysis showed significant inequalities in COVID-19 vaccine uptake between racial/ethnic populations in Canada. Further research is needed to understand the sociocultural, structural and systemic facilitators of and barriers to vaccination across racial groups, and to identify strategies that may improve vaccination uptake among First Nations and Black people.

OBJECTIVE:The purpose of this study was to measure the proportion of non-vaccination for pertussis in mothers in Canada who had been advised by their prenatal care provider to get vaccinated, and to identify sociodemographic factors and beliefs associated with non-vaccination.METHODS:The Survey on Vaccination during Pregnancy (part of childhood National Immunization Coverage Survey) included biological mothers of children born from September 2018 to March 2019. This analysis was restricted to 2657 mothers who had been advised by their prenatal care provider to get vaccinated against pertussis during pregnancy and knew whether or not they had been vaccinated.RESULTS:Of those who had been advised to get vaccinated against pertussis, 21% were not. This rate varied across provinces and territories, ranging from 9% in Prince Edward Island to 32% in Newfoundland and Labrador. Factors independently associated with pertussis non-vaccination included lower household income, having had past live births, and having received prenatal care from an obstetrician-gynecologist or a midwife compared to a family doctor. The risk of pertussis non-vaccination despite prenatal care advice was higher for those who disagreed that the baby would be at greater risk of pertussis if the mother did not get vaccinated. It was also higher for those who disagreed with statements regarding perceived benefits of vaccination. Conversely, disagreement with statements on perceived barriers was negatively associated with pertussis non-vaccination.CONCLUSION:These findings highlight the underlying factors associated with non-vaccination against pertussis despite prenatal care provider recommendation. Some inaccurate beliefs about pertussis and vaccination during pregnancy persist, leading to non-vaccination.

Abstract Background By July 2021, Canada had received enough COVID-19 vaccines to fully vaccinate every eligible Canadian. However, despite the availability of vaccines, some eligible individuals remain unvaccinated. Differences in vaccination uptake can be driven by health inequalities which have been exacerbated and amplified by the pandemic. This study aims to assess inequalities in COVID-19 vaccination uptake and intent in adults 18 years or older across Canada by identifying sociodemographic factors associated with non-vaccination and low vaccination intent using data drawn from the June to August 2021 Canadian Community Health Survey (CCHS). Methods The CCHS is an annual cross-sectional and nationally representative survey conducted by Statistics Canada, which collects health-related information. Since September 2020, questions about the COVID-19 pandemic are asked. Adjusted logistic regression models were fitted to examine associations between vaccination uptake or intent and sociodemographic and health related variables. Region, age, gender, level of education, Indigenous status, visible minority status, perceived health status, and having a regular healthcare provider were considered as predictors, among other factors. Results The analysis included 9,509 respondents. The proportion of unvaccinated was 11%. Non-vaccination was associated with less than university education (aOR up to 3.5, 95% CI 2.1–6.1), living with children under 12 years old (aOR 1.6, 95% CI 1.1–2.4), not having a regular healthcare provider (aOR 1.6, 95% CI 1.1–2.2), and poor self-perceived health (aOR 1.8, 95% CI 1.3–2.4). Only 5% of the population had low intention to get vaccinated. Being unlikely to get vaccinated was associated with the Prairies region (aOR 2.2, 95% CI 1.2–4.1), younger age groups (aOR up to 4.0, 95% CI 1.3–12.3), less than university education (aOR up to 3.8, 95% CI 1.9–7.6), not being part of a visible minority group (aOR 3.0, 95% CI 1.4–6.4), living with children under 12 years old (aOR 1.8, 95% CI 1.1–2.9), unattached individuals (aOR 2.6, 95% CI 1.1–6.1), and poor self-perceived health (aOR 2.0, 95% CI 1.3–2.9). Conclusions Disparities were observed in vaccination uptake and intent among various sociodemographic groups. Awareness of inequalities in COVID-19 vaccination uptake and intent is needed to determine the vaccination barriers to address in vaccination promotion strategies.

OBJECTIVE:This study was undertaken to measure the uptake of pertussis vaccination during pregnancy in Canada and to identify sociodemographic factors associated with non-vaccination.METHODS:A total of 5091 biological mothers of children born between September 2, 2018, and March 1, 2019, were interviewed about pertussis vaccination during their pregnancy.RESULTS:Among 4607 mothers who recalled whether they had been vaccinated for pertussis, 43% had been vaccinated and 57% had not. The main reason given by mothers for not having been vaccinated was not being aware that pertussis vaccination was recommended. Factors independently associated with non-vaccination were being born outside Canada, lower household income, living in a province or territory where pertussis vaccination was not provided free of charge, having had previous live births, and having received maternity care from a midwife.CONCLUSION:Advice from the maternity care provider is an important driver of pertussis vaccination during pregnancy.

The immunological basis for a >10-fold resistance of outbred CD-1 mice compared to inbred BALB/c mice to pulmonary blastomycosis was investigated. Bronchoalveolar macrophages (BAM) from CD-1 mice killed yeast cells of Blastomyces dermatitidis (Bd) by 25% and this increased to 59% when activated by IFN-γ. In contrast, BAM from BALB/c mice lacked significant killing (5%) of Bd but could be activated by IFN-γ for enhanced killing (19%). Peritoneal macrophages (PM) from CD-1 mice had significant fungicidal activity for Bd (43%) and this increased to 63% with IFN-γ treatment. By contrast, PM from BALB/c mice did not significantly kill Bd (14%) but were activated by IFN-γ for significant killing (24%). Fungicidal activity of peripheral blood polymorphonuclear neutrophils (PMN) from CD-1 (87%) was greater than that of BALB/c (75%) (P<0.05). Macrophage inflammatory protein-1α (MIP-1α) production by BAM from BALB/c was significantly less than that from CD-1 in response to co-culture with Bd. IFN-γ production by CD-1 spleen cells in response to concanavalin A (Con A, 1μg/ml) was 8-fold greater than that by BALB/c spleen cells. In contrast, BAM and PM from BALB/c mice in co-culture with Bd secreted several-fold more TNFα than BAM or PM from CD-1 mice. IL-2 production by BALB/c spleen cells in response to Con A was 3- to 4-fold greater than that by CD-1 spleen cells. Depressed IL-2 production by Con A stimulated CD-1 spleen cells correlated with depressed proliferative responses. Resistance of CD-1 mice to pulmonary blastomycosis correlates with enhanced fungicidal activity of BAM, PM, PMN, and IFN-γ production by Con A stimulated spleen cells, compared to BALB/c mice. Consistent with the in vitro enhancement of effector cell function by IFN-γ, in vivo therapy with IFN-γ significantly (P<0.0001) improved survival of BALB/c mice with pulmonary blastomycosis.

Childhood vaccination efforts in Canada have been negatively impacted by parents' vaccine hesitancy based on their knowledge, attitudes, and beliefs (KAB) about vaccinations. Less understood is the extent to which child vaccination receipt and KAB vary by parents' socioeconomic status (SES). Analyzing different age groups of children and vaccinations, we examine the extent to which (a) family SES (parent education, household income) is a determinant of Canadian parents' vaccination KAB and child vaccination receipt, and (b) whether SES was indirectly associated with receipt via KAB. In 2017, we analyzed 2013 Childhood National Immunization Coverage Survey (CNICS) data. We estimated models for parental KAB and child vaccination receipt for measles, mumps, and rubella (MMR) at age 2 (n = 3620); diphtheria, pertussis, and tetanus (DPT) at age 7 (n = 3465); and human papillomavirus (HPV) at ages 12-14 (n = 5213 females). SES is inconsistently associated with KAB and vaccine receipt across the three age groups. SES differences in KAB mostly center on vaccine-specific side effect and safety concerns, with lower education and income levels associated with higher odds of being concerned. Non-receipt of minimum age-specific vaccination dosages was associated with concerns about vaccine effectiveness (DPT, HPV) and side effects (MMR, HPV) and lower perceived importance of immunizing a child (MMR, HPV). KAB mediation was mostly limited to SES patterns in MMR. We discuss the implications of these findings for designing general and population-specific vaccination education strategies and future studies of KAB and undervaccination.

Newborns and infants less than 6 months of age continue to be at highest risk of severe outcomes from pertussis infection. Pertussis vaccination during the last trimester of pregnancy can confer protection to newborns as a result of trans-placental transfer of pertussis antibodies. In several countries, pertussis vaccination in pregnancy is recommended routinely and Canada’s National Advisory Committee on Immunization issued similar routine recommendations in February 2018. Using second trimester biobanked plasma samples (n = 1752) collected between 2008 and 2011, we measured the pre-existing anti-pertussis toxin (PT) levels in a large cohort of second-trimester pregnant women using a commercial ELISA test. We found that 97.5% of these women had anti-PT IgG titres below 35 IU/mL. Women with higher incomes had slightly higher anti-PT levels but 96% still had titres <35 IU/ml. In conclusion, almost all of the pregnant women in this large cohort had anti-PT levels low enough to suggest susceptibility to pertussis infection in both the mothers and their newborn infants.

The study objectives were to (1) identify determinants of non-vaccination against seasonal influenza in Canadian adults and (2) examine self-reported reasons for non-vaccination.

Background: In Canada, vaccine coverage for seasonal influenza remains below targets. Few studies have sought to determine the sociodemographic factors associated with non-vaccination using a Canada-wide survey. This study aims to identify the determinants of, and the reasons for, non-vaccination. Data and methods: Data from the 2013/2014 Canadian Community Health Survey (CCHS) were used. Respondents were divided into three groups: adults aged 18 to 64 years with a chronic medical condition (CMC), adults in the same age group with no CMC, and adults aged 65 years and older. Logistic regressions were used to measure the association between sociodemographic factors and non-vaccination. Results: Among adults aged 65 years and older, the proportion of non-vaccinated persons was 36.2%. This proportion was higher among adults aged 18 to 64 years with a CMC and those with no CMC (62.2% and 77.8%, respectively). Factors independently associated with non-vaccination in all groups included being young, having a lower level of education, and not having a family doctor. Among adults aged 65 years and older and 18 to 64 years with a CMC, excellent self-perceived health was also associated with non-vaccination. The belief that the vaccine is not necessary was the most common reason for non-vaccination. Interpretation: Too few Canadians get the influenza vaccine. The main reasons for not getting vaccinated have more to do with personal decision than barriers to access. This illustrates the ongoing need to inform the public about the importance of the vaccine and the risks associated with influenza.

1 World Health Organization Collaborating Centre for Research and Training in Parasite Epidemiology and Control, Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada, 2 Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland, 3 Department of Parasitology, College of Public Health, University of the PhilippinesManila, Philippines, 4 Department of Medicine, University of Melbourne, Parkville, Victoria, Australia, 5 GlaxoSmithKline, Twickenham, United Kingdom, 6 Neglected Tropical Diseases-Global Health, Bill and Melinda Gates Foundation, Seattle, Washington, United States of America, 7 Ciencias Médicas y de la Salud, Universidad Nacional de la Amazonia Peruana and Asociación Civil Selva Amazónica, Iquitos, Peru, 8 Department of Epidemiology of Infectious Diseases, St. George’s, University of London, London, United Kingdom, 9 Child Health, Ministry of Health and Family Welfare, New Delhi, India, 10 World Health Organization Collaborating Centre for Research and Training in Parasite Epidemiology and Control, Department of Epidemiology, Biostatistics and Occupational Health, Montreal, Quebec, Canada, 11 Children Without Worms, Atlanta, Georgia, United States of America, 12 National Helminth Control Programme, National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia, 13 Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institution and University of Basel, Basel, Switzerland, 14 Family, Women’s and Children’s Health, Maternal, Newborn, Child and Adolescent Health, Policy, Planning and Programmes, World Health Organization, Geneva, Switzerland, 15 STH Global Public Health, Johnson and Johnson, Raritan, New Jersey, United States of America, 16 Department of Virology, Parasitology, and Immunology, Ghent University, Merelbeke, Belgium

Vaccination coverage remains suboptimal in Canada and sporadic outbreaks of vaccine-preventable diseases such as measles and pertussis continue to occur. This study was undertaken to identify sociodemographic determinants of total non-vaccination (having never received any vaccine), non-vaccination for measles (0 doses) and incomplete vaccination for pertussis (< 4 doses) among 2-year-old Canadian children. Data from the 2013 Childhood National Immunization Coverage Survey (CNICS) were used. Associations between sociodemographic factors and outcomes were measured by multiple logistic regressions and adjusted odds ratios (aOR) were calculated. A total of 5,477 children were included in the analyses of total non-vaccination, and 3,899 children were included in the analysis of non-vaccination for measles and incomplete vaccination for pertussis. Overall, 2.7% of children (95% CI 2.0-3.3) had received no vaccine at all. Lower parental education, i.e., the responding parent having a high school diploma, trade certificate or less (compared with university graduation) was associated with total non-vaccination (aOR 1.99, 95% CI 1.02-3.91). Non-vaccination for measles was more frequent among children of single parent families (aOR 1.63, 95% CI 1.01-2.61) and those of parents with lower education (aOR 1.86, 95% CI 1.26-2.76). The odds of incomplete vaccination for pertussis was greater among children born outside Canada (aOR 3.10, 95% CI 1.73-5.58), of parents with lower education (aOR 1.92, 95% CI 1.41-2.62), and those whose household income was between $40,000 and $59,999 (aOR 1.47; 95% CI 1.04-2.07) or lower than $40,000 (aOR 1.58, 95% CI 1.13-2.22). Significant regional variation was also found for all outcomes. In conclusion, despite universal access to free childhood vaccines in Canada, regional variation and socioeconomic inequalities in vaccine uptake were still observed. Further analyses are warranted to identify barriers contributing to these variations.

Accurate and complete immunization data are necessary to assess vaccine coverage, safety and effectiveness. Across Canada, different methods and data sources are used to assess vaccine coverage, but these have not been systematically described. Our primary objective was to examine and describe the methods used to determine immunization coverage in Canada. The secondary objective was to compare routine infant and childhood coverage estimates derived from the Canadian 2013 Childhood National Immunization Coverage Survey (cNICS) with estimates collected from provinces and territories (P/Ts). We collected information from key informants regarding their provincial, territorial or federal methods for assessing immunization coverage. We also collected P/T coverage estimates for select antigens and birth cohorts to determine absolute differences between these and estimates from cNICS. Twenty-six individuals across 16 public health organizations participated between April and August 2015. Coverage surveys are conducted regularly for toddlers in Quebec and in one health authority in British Columbia. Across P/Ts, different methodologies for measuring coverage are used (e.g., valid doses, grace periods). Most P/Ts, except Ontario, measure up-to-date (UTD) coverage and 4 P/Ts also assess on-time coverage. The degree of concordance between P/T and cNICS coverage estimates varied by jurisdiction, antigen and age group. In addition to differences in the data sources and processes used for coverage assessment, there are also differences between Canadian P/Ts in the methods used for calculating immunization coverage. Comparisons between P/T and cNICS estimates leave remaining questions about the proportion of children fully vaccinated in Canada.

Delaying vaccination increases the period of vulnerability of children against vaccine-preventable diseases. We used a nationally representative sample of Canadian two-year-old children to explore factors associated with delays in the uptake of the first dose of measles-containing vaccine, recommended in Canada for children at 12 months of age. Distribution of delays was determined using data from the 2013 Childhood National Immunization Coverage Survey. Logistic regression was used to examine sociodemographic factors and knowledge, attitudes and beliefs (KAB) associated with the two outcomes of interest: delays of one to six months (vaccination at 13 to 18 months of age) and delays of seven to 18months (vaccination at 19 to 23 months of age). Overall, 69% (95% confidence interval [CI] 67-71) of children received their first valid dose on time. Twenty-nine percent (95% CI 27-31) and 11% (95% CI 9-12) of children were unvaccinated before turning 13 and 16months of age, respectively. Factors associated with delays of one to six months were being a girl, being born outside Canada, and the jurisdiction of residence. Being from a single-parent family, being born outside Canada and the jurisdiction of residence were associated with delays of seven to 18 months, suggesting that potential barriers might be at play. Associations between KAB and vaccination delays indicate that vaccine hesitancy could contribute to measles vaccination delays in Canada. Barriers in accessing vaccination services and the role of vaccine hesitancy in timely vaccination must be better understood to reduce vaccination delays in toddlers in Canada.