Influenza vaccination coverage across ethnic groups in Canada

Neurological Events Following COVID-19 Vaccination: Does Ethnicity Matter?

We conducted a retrospective cohort study in Ontario, Canada between December 1, 2020 and June 31, 2021 to compare the incidence of neurological events (hospitalization or emergency room visit) within six weeks of COVID-19 vaccination in Chinese, South Asian and Other ethnic groups. Compared to Others, the crude rates after the first dose for Bell's palsy, ischemic stroke and intracerebral hemorrhage were lower in Chinese (34, 159 and 48 per 1,000,000 doses) and in South Asians (44, 148 and 32), but similar after adjusting for age, sex and vaccine type. Our findings should help encourage vaccination for all, irrespective of ethnicity.

COVID-19 vaccine mistrust, health literacy, conspiracy theories, and racial discrimination among a representative ethnically diverse sample in Canada: The vulnerability of Arab, Asian, Black, and Indigenous peoples

Despite increased risk of severe acute respiratory syndrome coronavirus 2 infections and higher rates of COVID-19-related complications, racialized and Indigenous communities in Canada have lower immunization uptake compared to White individuals. However, there is woeful lack of data on predictors of COVID-19 vaccine mistrust (VM) that accounts for diverse social and cultural contexts within specific racialized and Indigenous communities. Therefore, we sought to characterize COVID-19 VM among Arab, Asian, Black, and Indigenous communities in Canada. An online survey was administered to a nationally representative, ethnically diverse panel of participants in October 2023. Arabic, Asian, Indigenous, and Black respondents were enriched in the sampling panel. Data were collected on demographics, COVID-19 VM, experience of racial discrimination, health literacy, and conspiracy beliefs. We used descriptive and regression analyses to determine the extent and predictors of COVID-19 VM among racialized and Indigenous individuals. All racialized respondents had higher VM score compared to White participants. Among 4220 respondents, we observed highest VM among Black individuals (12.18; ±4.24), followed by Arabic (12.12; ±4.60), Indigenous (11.84; ±5.18), Asian (10.61; ±4.28), and White (9.58; ±5.00) participants. In the hierarchical linear regression analyses, Black participants, women, everyday racial discrimination, and major experience of discrimination were positively associated with COVID-19 VM. Effects of racial discrimination were mediated by addition of conspiracy beliefs to the model. Racialized and Indigenous communities experience varying levels of COVID-19 VM and carry specific predictors and mediators to development of VM. This underscores the intricate interaction between race, gender, discrimination, and VM that need to be considered in future vaccination campaigns.

A population-based, province-wide, record-linkage interrupted time series analysis of impact of the universal seasonal influenza vaccination policy on seasonal influenza vaccine uptake among 5-64-year-olds in the province of Manitoba, Canada

INTRODUCTION

Universal seasonal influenza vaccination policy (USIVP) was introduced in Manitoba, Canada in 2010. Its impact on seasonal influenza vaccine (SIV) uptake remains underexplored.

METHODS

We used population-wide data from Manitoba to assess the impact of the USIVP on SIV uptake. The study covered twenty influenza seasons (2000/01-2019/20). We summarized SIV uptake for influenza seasons before and after the USIVP. Utilizing a single-group interrupted time series analysis and appropriately accounting for autocorrelation, we estimated absolute change and annual trend in SIV uptake percentages among 5-17-, 18-44-, and 45-64-year-olds across strata of certain population socioeconomic and health-related characteristics following the USIVP.

RESULTS

Average SIV uptake percentage in all age groups was significantly higher after compared with before the USIVP. Following the USIVP, there was no significant absolute change in SIV uptake percentage among 18-44- and 45-64-year-olds overall; however, a significant decrease was observed among 18-44-year-old males in the higher income quintiles, across healthcare utilization, and in some regions of residence. A significant increase was observed among 5-17-year-olds in the lowest income quintiles, in Northern Manitoba, and among those with less healthcare utilization, and no chronic disease. Overall, there was mostly no significant annual trend in SIV uptake percentage among 18-44-year-olds, and while a significant upward and downward trend was observed among 5-17-year-olds and 45-64-year-olds, respectively, a significant downward trend was observed across all strata of population characteristics within all age groups in Northern Manitoba.

CONCLUSIONS

The USIVP in Manitoba was followed by an absolute increase in SIV uptake percentage only in some socioeconomically disadvantaged subpopulations among 5-17-year-olds. While there was mostly an upward annual trend in SIV uptake percentage among 5-17-year-olds, a downward trend was observed among 45-64-year-olds and across all age groups and subpopulations in socioeconomically disadvantaged Northern Manitoba. These findings are novel for Manitoba and require investigation and public health attention.

Hepatitis B and influenza vaccination coverage in healthcare workers, the elderly, and patients with diabetes in Malaysia

Adult immunization remains to be a neglected issue in developing countries including Malaysia. This nationwide study determined the vaccination coverage of hepatitis B and influenza among Malaysia's healthcare workers (HCWs), the elderly (aged 60 y and above) and patients with diabetes, who are the participants of The Malaysia Cohort Program. The participants were categorized based on their occupation, age and medical history. Self-reported questionnaire was used to assess the participant's hepatitis B and influenza vaccination status. A Chi-square test and logistic regression analyses were performed to determine the risk factors associated with vaccination behavior. The hepatitis B vaccination coverage for healthcare workers, elderly, and patients with diabetes were 34.6%, 10.1% and 9.8%, respectively. The influenza vaccination coverage rates for healthcare workers, the elderly and patients with diabetes were 26.3%, 5.5% and 6.4%, respectively. The Chinese were more likely to be vaccinated against hepatitis B, while Malay was more likely to be vaccinated against influenza. Individuals with higher education and living in urban areas were more likely vaccinated than those with low education levels and who lived in rural areas. The low vaccination coverage for healthcare workers was alarming because hepatitis B and influenza were subsidized for the healthcare workers. The hepatitis B and influenza vaccination coverage among healthcare workers, elderly and patients with diabetes in Malaysia were low. Specific interventions such as educational and awareness programs should be conducted to increase the vaccination rate among adults, especially those at high risk.

Improved vaccine coverage for First Nations children receiving first dose on-reserve: a retrospective cohort study in western Canada

INTRODUCTION

Fragmentation in immunisation reporting systems pose challenges in measuring vaccine coverage for First Nations children in Canada. Some Nations have entered into data-sharing agreements with the province of Alberta's health ministry, enabling novel opportunities to calculate coverage.

METHODS

Partnering with a First Nations community in Alberta, this retrospective cohort study calculated routine childhood vaccine coverage. Administrative data for vaccines delivered within and outside the community were linked to calculate partial and complete immunisation coverage in 2013-2019 at ages 2 and 7 years for children living in the community. We also compared vaccine coverage each year for (a) children who were and were not continuous community residents and (b) children who received or not their first vaccine at the on-reserve community health centre. We also calculated the mean complete coverage across all study years with 95% CIs.

RESULTS

For most vaccines, coverage was higher (p<0.05) at ages 2 and 7 years for children that received their first vaccine at the First Nations health centre, compared with those who received their first dose elsewhere. For example, for pneumococcal vaccine, the mean level of complete coverage in 2-year-olds was 55.7% (52.5%-58.8%) for those who received their first vaccine in the community, compared with 33.3% (29.4%-37.3%) for those who did not; it was also higher at 7 years (75.6%, 72.7%-78.5%, compared with 55.5%, 49.7%-61.3%).

CONCLUSION

Initiating the vaccine series at the on-reserve community health centre had a positive impact on coverage. The ability to measure accurate coverage through data-sharing agreements and vaccine record linkage will support First Nations communities in identifying individual and community immunity. The findings also support the transfer of health funding and service delivery to First Nations to improve childhood immunisation uptake.

Racial disparities in COVID-19 vaccination in Canada: results from the cross-sectional Canadian Community Health Survey

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.

Impact of the universal seasonal influenza vaccination policy in the province of Manitoba, Canada: A population-based, province-wide record-linkage study

INTRODUCTION

In 2010, the government of the province of Manitoba, Canada introduced universal seasonal influenza vaccination policy (USIVP), providing free-of-charge vaccination to all registered residents of the province at least six months of age. Impact of the policy on seasonal influenza vaccine (SIV) uptake (receipt of vaccine) in Manitoba remains unclear, as there is a lack of published evaluations.

METHODS

We conducted an ecological study, utilizing population-wide data from several linked de-identified Manitoba Health and Seniors Care administrative health databases. The study period was from 2000/01-2019/20 influenza seasons. The primary exposure was USIVP (five influenza seasons pre-policy [2005/06-2009/10] compared with post-policy [2010/11-2014/15]). The outcome was SIV uptake. We conducted pre/post logistic regression analysis stratified by age group (<5-, 5-17-, 18-44-, 45-64-, ≥65-year-olds) and certain population socioeconomic and health-related characteristics. Results are adjusted odds ratios with associated 95 % confidence intervals.

RESULTS

We observed significantly increased adjusted odds of SIV uptake post-policy relative to pre-policy in all age groups except ≥65-year-olds already covered from inception of the vaccination programme. The adjusted odds ratios ranged from 0.76 (0.75-0.76) among ≥65-year-olds to 2.15 (2.13-2.18) among 5-17-year-olds, and were largely homogeneous within age groups across sex, income quintiles, regions of residence, and categories of number of visits to primary care physician/hospitalization one year prior to an influenza season except among <5- and 5-17-year-olds. These findings were mostly consistent irrespective of sex and region of residence although there was variability across income quintiles in Northern Manitoba region.

CONCLUSIONS

Introduction of the USIVP in Manitoba was followed by a significant increase in SIV uptake in the five years post policy among <65-year-olds, with similar increased relative odds of vaccination observed within age groups across subpopulations. The observed variations in the relative odds of vaccination across income quintiles in Northern Manitoba region requires administrative attention.

Perceived facilitators and barriers to the uptake of the human papillomavirus (HPV) vaccine among adolescents of Arabic-speaking mothers in NSW, Australia: A qualitative study

Background

Australia has a large immigrant population but there is little data regarding whether human papillomavirus (HPV) vaccination coverage in adolescents varies according to parents' cultural or ethnic background. This work aims to identify facilitators and barriers to HPV vaccination of adolescents as perceived by Arabic-speaking mothers in Western Sydney, South Western Sydney and Wollongong, NSW, Australia.

Methods

A purposive sampling approach was applied to recruit mothers of adolescents from Arabic speaking backgrounds who had at least one child eligible for the HPV school-based vaccination program. Face-to-face semi-structured well as online interviews were conducted in Arabic between April 2021 and July 2021. The interviews were audio-recorded, transcribed, and translated into English and examined using thematic analysis.

Results

Sixteen mothers of adolescents from Arabic backgrounds described facilitators and barriers to HPV vaccination. A) Facilitators of HPV vaccination included: knowledge of HPV disease, trust in the school vaccination program, opportunistic recommendations from healthcare workers, information from friends. B) Barriers to accessing HPV vaccination included communication gaps: breakdown in school-parent information flow, lack of access to the Arabic language version of the information sheet, mother - GP communication barriers, mother-child communication gap; and health system gaps: missed opportunities for vaccination. C) Mothers' suggestions to improve HPV vaccination acceptance: to involve religious and cultural leadership, encourage engagement with GPs, and provide school-based education for parents and students.

Conclusion

Parents could benefit from assistance with HPV vaccination decision making. Interventions via schools, health professionals and religious and cultural organisations could play important roles in HPV vaccination acceptance for Arabic speaking immigrant families and in introducing their adolescent children to this vaccine.

Barriers experienced by families new to Alberta, Canada when accessing routine-childhood vaccinations

BACKGROUND

As Canada and other high-income countries continue to welcome newcomers, we aimed to 1) understand newcomer parents' attitudes towards routine-childhood vaccinations (RCVs), and 2) identify barriers newcomer parents face when accessing RCVs in Alberta, Canada.

METHODS

Between July 6th-August 31st, 2022, we recruited participants from Alberta, Canada to participate in moderated focus group discussions. Inclusion criteria included parents who had lived in Canada for < 5 years with children < 18 years old. Focus groups were transcribed verbatim and analyzed using content and deductive thematic analysis. The capability opportunity motivation behaviour model was used as our conceptual framework.

RESULTS

Four virtual and three in-person focus groups were conducted with 47 participants. Overall, parents were motivated and willing to vaccinate their children but experienced several barriers related to their capability and opportunity to access RCVs. Five main themes emerged: 1) lack of reputable information about RCVs, 2) language barriers when looking for information and asking questions about RCVs, 3) lack of access to a primary care provider (PCP), 4) lack of affordable and convenient transportation options, and 5) due to the COVID-19 pandemic, lack of available vaccine appointments. Several minor themes were also identified and included barriers such as lack of 1) childcare, vaccine record sharing, PCP follow-up.

CONCLUSIONS

Our findings highlight that several barriers faced by newcomer families ultimately stem from issues related to accessing information about RCVs and the challenges families face once at vaccination clinics, highlighting opportunities for health systems to better support newcomers in accessing RCVs.

Prevalence of influenza-specific vaccination hesitancy among adults in the United States, 2018

BACKGROUND

The role of vaccine hesitancy on influenza vaccination is not clearly understood. Low influenza vaccination coverage in U.S. adults suggests that a multitude of factors may be responsible for under-vaccination or non-vaccination including vaccine hesitancy. Understanding the role of influenza vaccination hesitancy is important for targeted messaging and intervention to increase influenza vaccine confidence and uptake. The objective of this study was to quantify the prevalence of adult influenza vaccination hesitancy (IVH) and examine association of IVH beliefs with sociodemographic factors and early-season influenza vaccination.

METHODS

A four-question validated IVH module was included in the 2018 National Internet Flu Survey. Weighted proportions and multivariable logistic regression models were used to identify correlates of IVH beliefs.

RESULTS

Overall, 36.9% of adults were hesitant to receive an influenza vaccination; 18.6% expressed concerns about vaccination side effects; 14.8% personally knew someone with serious side effects; and 35.6% reported that their healthcare provider was not the most trusted source of information about influenza vaccinations. Influenza vaccination ranged from 15.3 to 45.2 percentage points lower among adults self-reporting any of the four IVH beliefs. Being female, age 18-49 years, non-Hispanic Black, having high school or lower education, being employed, and not having primary care medical home were associated with hesitancy.

CONCLUSIONS

Among the four IVH beliefs studied, being hesitant to receiving influenza vaccination followed by mistrust of healthcare providers were identified as the most influential hesitancy beliefs. Two in five adults in the United States were hesitant to receive an influenza vaccination, and hesitancy was negatively associated with vaccination. This information may assist with targeted interventions, personalized to the individual, to reduce hesitancy and thus improve influenza vaccination acceptance.

Determinants of SARS-CoV-2 vaccine willingness among people incarcerated in 3 Canadian federal prisons: a cross-sectional study

BACKGROUND

Maximizing uptake of SARS-CoV-2 vaccines among people in prison is essential in mitigating future outbreaks. We aimed to determine factors associated with willingness to receive SARS-CoV-2 vaccination before vaccine availability.

METHODS

We chose 3 Canadian federal prisons based on their low uptake of influenza vaccines in 2019-2020. Participants completed a self-administered questionnaire on knowledge, attitude and beliefs toward vaccines. The primary outcome was participant willingness to receive a SARS-CoV-2 vaccine, measured using a 5-point Likert scale to the question, "If a safe and effective COVID-19 vaccine becomes available in prison, how likely are you to get vaccinated?" We calculated the association of independent variables (age, ethnicity, chronic health conditions, 2019-2020 influenza vaccine uptake and prison security level), identified a priori, with vaccine willingness using logistic regression and crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

We recruited 240 participants from Mar. 31 to Apr. 19, 2021 (median age 46 years; 19.2% female, 25.8% Indigenous). Of these, 178 (74.2%) were very willing to receive a SARS-CoV-2 vaccine. Participants who received the 2019-2020 influenza vaccine (adjusted OR 5.20, 95% CI 2.43-12.00) had higher odds of vaccine willingness than those who did not; those who self-identified as Indigenous (adjusted OR 0.27, 95% CI 0.11-0.60) and in medium- or maximum-security prisons (adjusted OR 0.36, 95% CI 0.12-0.92) had lower odds of vaccine willingness than those who identified as white or those in minimum-security prisons, respectively.

INTERPRETATION

Most participants were very willing to receive vaccination against SARS-CoV-2 before vaccine roll-out. Vaccine promotion campaigns should target groups with low vaccine willingness (i.e., those who have declined influenza vaccine, identify as Indigenous or reside in high-security prisons).

Understanding predictors of pneumococcal vaccine uptake in older adults aged 65 years and older in high-income countries across the globe: A scoping review

BACKGROUND

Pneumococcal disease causes substantial morbidity and mortality in older adults. Pneumococcal polysaccharide vaccine (PPV23) is routinely recommended to reduce the disease burden in this population. However, the vaccination coverage in older adults remains suboptimal in high-income countries.

OBJECTIVES

We sought to understand the current landscape of published literature on the predictors of pneumococcal vaccine uptake in older adults aged 65 years and older in high-income countries, and to identify the gaps in literature to inform future research.

METHODS

We conducted a scoping review employing the Arksey and O'Malley framework and Joanna Briggs Methods. We searched Medline, EMBASE, CINAHL, PsycInfo and Cochrane databases. We included quantitative and qualitative studies on predictors of pneumococcal vaccination in older adults that reported older adult- and pneumococcal vaccine-specific results, conducted in high-income settings, and published in English between January 2015 and April 2020. We excluded studies assessing interventions to improve vaccine uptake. We followed the Strategic Advisory Group of Experts on Immunization Working Group Vaccine Hesitancy Determinants Matrix to map the predictors within contextual, individual and social group, and vaccine and vaccination-specific influence determinants. Studies on providers and institutions were also included and results summarized separately.

RESULTS

We included 52 publications in our review. Most of the predictors in 39 quantitative studies belonged to the individual and social group influences (n = 12), followed by contextual influences (n = 11) and vaccine and vaccination-specific issues (n = 3). Few qualitative studies explored the barriers to pneumococcal vaccination. Only five studies examined predictors from the healthcare providers' perspective. Three studies examined the institutional characteristics as the predictors of pneumococcal vaccination in older adults.

CONCLUSIONS

We identified enablers and barriers of pneumococcal vaccination among older adults in high-income settings. We also identified gaps in the literature and provide recommendations for future research to address the gaps.

HPV vaccine: uptake and understanding among global Indigenous communities - a qualitative systematic review

BACKGROUND

Indigenous populations have a high prevalence of Human Papillomavirus (HPV) infection and a high incidence of HPV associated cancers, such as cervical and oropharyngeal cancer. There is an effective HPV vaccination program in almost all developed countries to prevent the incidence of cervical cancer, but reports suggest that the uptake of these vaccinations by Indigenous populations is low. The objective of this qualitative systematic review was to explore the knowledge and beliefs of global Indigenous populations regarding HPV vaccines. This review was performed to identify the barriers faced by Indigenous peoples and to provide evidence for more effective and acceptable execution of vaccination policies for Indigenous peoples.

METHODS

Two investigators independently searched MEDLINE, PubMed, SCOPUS, and Web of Science databases using a pre-specified search strategy to identify qualitative studies on narratives of Indigenous peoples regarding HPV vaccine awareness, knowledge and experiences across all geographic and income-level settings.

RESULTS

After performing the literature search and quality appraisals 5 papers were included in the final review. Three core synthesised findings were identified: reasons for acceptance or hesitancy, and areas for improvement. Lack of correct knowledge and mistrust in the healthcare system were important categories observed in all papers included in the review. Other categories within the conceptual model included prioritising disease prevention, health professional guidance, family support and supportive community environment.

CONCLUSION

Qualitative systematic reviews are an excellent means of exploring the gaps in current healthcare practices. Indigenous healthcare research should be grounded in community experiences and feedback. This review provides insights into HPV vaccination understanding and acceptance amongst Indigenous populations, from which recommendations for increasing resonance of vaccination strategies with Indigenous communities can be formed.

Factors associated with seasonal influenza and HPV vaccination uptake among different ethnic groups in Arab and Jewish society in Israel

Background

Parents in the Arab population of Israel are known to be “pro-vaccination” and vaccinate their children at higher rates than the Jewish population, specifically against human papilloma virus (HPV) and seasonal influenza.

Objectives

This study seeks to identify and compare variables associated with mothers’ uptake of two vaccinations, influenza and HPV, among different subgroups in Arab and Jewish society in Israel.

Methods

A cross-sectional study of the entire spectrum of the Israeli population was conducted using a stratified sample of Jewish mothers (n = 159) and Arab mothers (n = 534) from different subgroups: Muslim, Christian, Druse and Northern Bedouins. From March 30, 2019 through October 20, 2019, questionnaires were distributed manually to eighth grade pupils (13–14 years old) who had younger siblings in second (7–8 years old) or third (8–9 years old) grades.

Results

Arab mothers exhibited a higher rate of uptake for both vaccinations (p < .0001, HPV – 90%; influenza – 62%) than Jewish mothers (p = 0.0014, HPV – 46%; influenza – 34%). Furthermore, results showed that HPV vaccination uptake is significantly higher than seasonal influenza vaccination uptake in both populations. Examination of the different ethnic subgroups revealed differences in vaccination uptake. For both vaccinations, the Northern Bedouins exhibited the highest uptake rate of all the Arab subgroups (74%), followed by the Druse (74%) and Muslim groups (60%). The Christian Arab group exhibited the lowest uptake rate (46%). Moreover, the uptake rate among secular Jewish mothers was lower than in any of the Arab groups (38%), though higher than among religious/traditional Jewish mothers, who exhibited the lowest uptake rate (26%). A comparison of the variables associated with mothers’ vaccination uptake revealed differences between the ethnic subgroups.

Moreover, the findings of the multiple logistic regression revealed the following to be the most significant factors in Arab mothers’ intake of both vaccinations: school-located vaccination and mothers’ perceived risk and perceived trust in the system and in the family physician. These variables are manifested differently in the different ethnic groups.

Conclusions

This research shows that all Arabs cannot be lumped together as one monolithic group in that they exhibit major differences according to religion, education and access to information. Ranking of variables associated with uptake of the two vaccines can provide decision-makers an empirical basis for tailoring appropriate and specific interventions to each subgroup to achieve the highest vaccine uptake rate possible. Media campaigns targeting the Arab population should be segmented to appeal to the various sub-groups according to their viewpoints, needs and health literacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-021-01523-1.

Human papillomavirus (HPV) vaccine uptake among a community-recruited sample of gay, bisexual, and other men who have sex with men in the three largest cities in Canada from 2017 to 2019

INTRODUCTION

In 2015/2016, Canada's largest provinces implemented publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) ≤ 26 years old. We sought to describe HPV vaccine uptake among GBM and determine barriers and facilitators to vaccine initiation with a focus on healthcare access and utilization.

METHODS

Engage is a cohort study among GBM aged 16 + years in three Canadian cities recruited from 2017 to 2019 via respondent driven sampling (RDS). Men completed a comprehensive questionnaire at baseline. By publicly-funded vaccine eligibility (≤26 years old = eligible for vaccination, ≥27 years old = ineligible), we described HPV vaccine uptake (initiation = 1 + dose, completion = 3 doses) and explored factors associated with vaccine initiation using Poisson regression. All analyses were weighted with the RDS-II Volz-Heckathorn estimator.

RESULTS

Across the three cities, 26-35% and 14-21% of men ≤ 26 years and 7-26% and 2-9% of men ≥ 27 years initiated and completed HPV vaccination, respectively. Vaccine initiation was significantly associated with STI/HIV testing or visiting a HIV care specialist in the past six months (≤26: prevalence ratio[PR] = 2.15, 95% confidence interval[CI] 1.06-4.36; ≥27: PR = 2.73, 95%CI 1.14-6.51) and past hepatitis A or B vaccination (≤26: PR = 2.88, 95%CI 1.64-5.05; ≥27: PR = 2.03, 95%CI 1.07-3.86). Among men ≥ 27 years old, vaccine initiation was also positively associated with accessing PrEP, living in Vancouver or Toronto, but negatively associated with identifying as Latin American and increasing age. Vaccine initiation was twice as likely among men ≥ 27 years with private insurance versus no insurance.

CONCLUSIONS

Sixty-five to 74% of men eligible for publicly-funded vaccine across the three cities remained unvaccinated against HPV by 2019. High vaccine cost may partly explain even lower uptake among men ≥ 27 years old. Men seeking sexual health care were more likely to initiate vaccination; bundling vaccination with these services may help improve HPV vaccine uptake.

The geographic distribution of un-immunized children in Ontario, Canada: Hotspot detection using Bayesian spatial analysis

BACKGROUND

In Ontario, Canada, little is currently known about the extent to which un-immunized children may cluster geographically. Our objectives were to: describe the geographic distribution of fully un-immunized children; identify geographic clusters (hotspots) of un-immunized children; and to characterize the contribution of spatial effects and covariates on hotspots, where found.

METHODS

Our analytic cohort consisted of Ontario students aged 7-17 years in the 2016-2017 school year. We defined students as un-immunized if they had zero doses of any vaccine and a non-medical exemption recorded in Ontario's registry. We calculated unadjusted proportions of un-immunized students by Census Subdivision (CSD) and then used a sequential approach to identify hotspots starting first with hotspot identification at the CSD level and then probed identified hotspots further by Dissemination Area (DA) and including covariates. Hotspots were identified using the Besag-York-Mollie Bayesian spatial model and were defined as areas with >95% probability of having two times the proportion of un-immunized students, relative to the province overall.

RESULTS

We identified 15,208 (0.94%) un-immunized children within our cohort consisting of more than 1.61 million students. Unadjusted proportions of un-immunized students varied greatly by geography, ranging from 0% to 21.5% by CSD. We identified 16 hotspot CSDs which clustered in five distinct areas, all of which were located in southern Ontario. The contribution of covariates and spatial effects on the risk of having un-immunized students varied greatly across hotspot areas.

CONCLUSIONS

Although the provincial proportion (0.94%) of un-immunized students is small, geographical clustering of such students is evident in Ontario and in some areas presents an important risk for future outbreaks. Further qualitative work within these hotspot areas would be a helpful next step to better characterize the factors associated with vaccine refusal in these communities.

Newcomer knowledge, attitudes, and beliefs about human papillomavirus (HPV) vaccination

BACKGROUND

Human Papillomavirus (HPV) is the most common sexually transmitted infection in Canada and around the world. Vaccination is an effective prevention strategy, but uptake is low, especially among newcomers to Canada. We sought to understand newcomers' knowledge, attitudes, and beliefs (KAB) on HPV and HPV vaccination and their role in HPV vaccine acceptance.

METHODS

Newcomers were defined as individuals born outside Canada, (i.e., individuals born in a different country, the majority of whom are immigrants or refugees, but also includes students and undocumented migrants). Eligible participants were newcomers, aged 16 or older and who could read or write in English, French or Arabic. Surveys were administered in two community health centres in Ottawa, Canada that primarily engage with newcomer populations. Follow-up interviews were conducted either at the community health centre or over the phone, depending on participants' preferences.

RESULTS

Fifty participants completed the survey, the majority of whom were women (74%) and spoke Arabic as their first language (54%). Seven participants completed supplemental interviews to complement their survey responses. The majority (70%) of participants had not previously heard of HPV. Less than half (46%) knew that the vaccine is effective in preventing certain types of cancer; nearly 40% incorrectly believed the vaccine could cure HPV. Qualitative interviews supported the survey findings.

CONCLUSIONS

Despite a lack of HPV knowledge due to cultural and language barriers, there is still a strong desire among newcomers to receive the vaccine, especially when accompanied by a physician recommendation. Cultural and language-appropriate resources are needed to help newcomers make informed vaccination decisions and promote HPV vaccine uptake.

Perceived trust in the health system among mothers and nurses and its relationship to the issue of vaccinations among the Arab population of Israel: A qualitative research study

The literature indicates that trust plays an important role in people's decision-making with respect to vaccinations. This research seeks to examine the impact of trust on the high response rate to vaccinations among the minority Arab population living in Israel. The research employs the qualitative phenomenological research method, using personal interviews to identify and analyze perceived trust among mothers of young children and teenagers (n = 70) and among nurses (n = 20) in the Arab population in the context of vaccinations and the high response rate to vaccinations among this population. The research findings point to differing levels of trust in the medical system. The participants placed the highest trust in the nurses working in the Tipat Halav Family Health Centers run by the Ministry of Health. These nurses are the main communicators of information about childhood vaccinations in Israel. Moreover, the interviewees saw vaccinations as an example of the state offering equal and optimal services to the Arab minority population. In addition, the interviewees consider the explanatory materials to be limited, superficial and not culturally appropriate. These positive attitudes toward vaccinations alongside reports that no importance is attributed to the explanatory materials due to their low quality may cause the population to accept vaccination recommendations as they are and to delegate responsibility and authority to the state.

Factors Related to Chinese Parents' HPV Vaccination Intention for Children

Objectives: Successful human papilloma virus (HPV) vaccine delivery depends heavily on parents' attitudes, perceptions, and willingness to have their children vaccinated. In this study, we assessed parental knowledge, attitudes, and beliefs about the HPV vaccine, and examine factors associated with willingness to have eligible children receive HPV vaccination. Methods: From a community health center serving Chinese members in the Greater Philadelphia area, 110 Chinese-American parents with at least one child aged 11 to 18 who had not received HPV vaccine were recruited. Data were collected in face-to-face interviews. Results: Chinese-American parents generally lacked knowledge on HPV and the HPV vaccine, yet had a moderately high level of intention to vaccinate their children against HPV. Ordinal logistic regression results indicated that knowledge, whether or not to involve children, doctor influence, and time lived in the United States were significantly and independently related to parental intention to have their children vaccinated against HPV. Conclusion: Interventions should make efforts to raise awareness of HPV and promote vaccination in doctors' offices. The lower level of parental intention among relatively recent immigrants indicated the necessity to target this population in public health campaigns and intervention efforts.

Are we speaking the same language? an argument for the consistent use of terminology and definitions for childhood vaccination indicators

Vaccination indicators are used to measure the health status of individuals or populations and to evaluate the effectiveness of vaccination programs or policies. Ensuring that vaccination indicators are clearly and consistently defined is important for effective communication of outcomes, accurate program evaluation, and comparison between different populations, times, and contexts. The purpose of this commentary is to describe commonly used vaccination indicators and to highlight inconsistencies in how childhood vaccine researchers use and define these terms. The indicators we describe are vaccine coverage, uptake, and rate; vaccination status, initiation, and completion; and up-to-date, timely, partial, and incomplete vaccination. We conclude that many vaccination indicators are not explicitly defined within published research studies and/or are used quite differently across studies. We also note that the choice of indicator in a given study is often driven by program or vaccine specific factors, may be constrained by data availability, and should be chosen to best reflect the outcome of interest. We conclude that the use of consistent language and definitions would promote more effective communication of research findings. We also propose some standardized definitions for common indicators, with the goal of provoking discussion and debate on the issue.

Influenza Vaccination Coverage Among English-Speaking Asian Americans

INTRODUCTION

English-speaking non-Hispanic Asians (Asians) in the U.S. include populations with multiple geographic origins and ethnicities (e.g., Asian Indian, Chinese, Filipino, Japanese, Korean, and Vietnamese). Health behaviors and outcomes can differ widely among Asian ethnicities, and highlight the importance of subgroup analysis. Aggregating Asians may mask differences in influenza vaccination across various ethnicities.

METHODS

Combined data from 2013 to 2015 Behavioral Risk Factor Surveillance System, a population-based, telephone survey of the non-institutionalized, U.S. population aged ≥18years, were analyzed in 2017 to assess influenza vaccination among Asians. Weighted proportions were calculated. Multivariable logistic regression was used to determine independent associations between sociodemographic factors and receipt of influenza vaccination.

RESULTS

Influenza vaccination varied widely among Asian ethnicities, both nationally and by state. Overall, 42.1% of Asians reported having received an influenza vaccine, similar to vaccination among whites (42.4%). Coverage ranged from 36.1% among Koreans to 50.9% among Japanese. Factors independently associated with influenza vaccination among some or all Asian ethnicities included age (≥50 years), female, never married, high school or higher education, annual household income ≥$75,000, possession of medical insurance and personal healthcare provider, routine checkup in the previous year, and presence of certain chronic conditions.

CONCLUSIONS

Though Asians and whites had similar overall influenza vaccination coverage, differences existed between Asian ethnicities, both nationally and by state. This information may help community-based, state-level, and national-level public health agencies to support targeted approaches for outreach to these populations, such as improving cultural and linguistic access to care, to improve influenza vaccination.

Barriers, supports, and effective interventions for uptake of human papillomavirus- and other vaccines within global and Canadian Indigenous peoples: a systematic review protocol

BACKGROUND

Despite the existence of human papilloma virus (HPV) vaccines with demonstrated safety and effectiveness and funded HPV vaccination programs, coverage rates are persistently lower and cervical cancer burden higher among Canadian Indigenous peoples. Barriers and supports to HPV vaccination in Indigenous peoples have not been systematically documented, nor have interventions to increase uptake in this population. This protocol aims to appraise the literature in Canadian and global Indigenous peoples, relating to documented barriers and supports to vaccination and interventions to increase acceptability/uptake or reduce hesitancy of vaccination. Although HPV vaccination is the primary focus, we anticipate only a small number of relevant studies to emerge from the search and will, therefore, employ a broad search strategy to capture literature related to both HPV vaccination and vaccination in general in global Indigenous peoples.

METHODS

Eligible studies will include global Indigenous peoples and discuss barriers or supports and/or interventions to improve uptake or to reduce hesitancy, for the HPV vaccine and/or other vaccines. Primary outcomes are documented barriers or supports or interventions. All study designs meeting inclusion criteria will be considered, without restricting by language, location, or data type. We will use an a priori search strategy, comprised of key words and controlled vocabulary terms, developed in consultation with an academic librarian, and reviewed by a second academic librarian using the PRESS checklist. We will search several electronic databases from date of inception, without restrictions. A pre-defined group of global Indigenous websites will be reviewed for relevant gray literature. Bibliographic searches will be conducted for all included studies to identify relevant reviews. Data analysis will include an inductive, qualitative, thematic synthesis and a quantitative analysis of measured barriers and supports, as well as a descriptive synthesis and quantitative summary of measures for interventions.

DISCUSSION

To our knowledge, this study will contribute the first systematic review of documented barriers, supports, and interventions for vaccination in general and for HPV vaccination. The results of this study are expected to inform future research, policies, programs, and community-driven initiatives to enhance acceptability and uptake of HPV vaccination among Indigenous peoples.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO Registration Number: CRD42017048844.

Barriers to immunization among newcomers: A systematic review

INTRODUCTION

Currently, there is a lack of comprehensive evidence exploring vaccine decision-making among newcomers. We conducted a systematic review of qualitative studies aimed at identifying factors that influence newcomers' decision-making with regards to vaccination.

METHODS

We conducted a search of MEDLINE, EMBASE, CINAHL and Cochrane Central. To be included, studies needed to employ a qualitative methodology and address newcomer attitudes, beliefs, and/or perceptions regarding vaccination. Two independent reviewers screened the articles for relevant information and applied a content analysis methodology to code the identified barriers.

RESULTS

Twenty-one studies were included in this review, and four types of barriers were identified: cultural factors, knowledge barriers, insufficient access to healthcare, and vaccine hesitancy. Insufficient knowledge about vaccination and the virus being prevented and concerns about safety were the most commonly reported barriers. A sub-analysis of barriers specific to HPV indicated that cultural beliefs about sexuality and incomplete knowledge about the role of HPV in the development of cervical cancer are major barriers to vaccine uptake.

CONCLUSION

Strategies to improve vaccination uptake in newcomers should consider focusing on the barriers identified in this review while taking into account the unique opportunities for promoting uptake within newcomer populations.

Facebook Recruitment of Vaccine-Hesitant Canadian Parents: Cross-Sectional Study

Background

There is concern over the increase in the number of “vaccine-hesitant” parents, which contributes to under-vaccinated populations and reduced herd immunity. Traditional studies investigating parental immunization beliefs and practices have relied on random digit dialing (RDD); however, this method presents increasing limitations. Facebook is the most used social media platform in Canada and presents an opportunity to recruit vaccine-hesitant parents in a novel manner.

Objective

The study aimed to explore the use of Facebook as a tool to reach vaccine-hesitant parents, as compared with RDD methods.

Methods

We recruited Canadian parents over 4 weeks in 2013-14 via targeted Facebook advertisements linked to a Web-based survey. We compared methodological parameters, key parental demographics, and three vaccine hesitancy indicators to an RDD sample of Canadian parents. Two raters categorized respondent reasons for difficulties in deciding to vaccinate, according to the model of determinants of vaccine hesitancy developed by the World Health Organization’s Strategic Advisory Group of Experts on Immunization.

Results

The Facebook campaign received a total of 4792 clicks from unique users, of whom 1696 started the Web-based survey. The total response rate of fully completed unique Web-based surveys was 22.89% (1097/4792) and the survey completion rate was 64.68% (1097/1696). The total cost including incentives was reasonable (Can $4861.19). The Web-based sample yielded younger parents, with 85.69% (940/1097) under the age of 40 years as compared with 23.38% (408/1745) in the RDD sample; 91.43% (1003/1097) of the Facebook respondents were female as compared with 59.26% (1034/1745) in the RDD sample. Facebook respondents had a lower median age of their youngest child (1 year vs 8 years for RDD). When compared with the RDD sample, the Web-based sample yielded a significantly higher proportion of respondents reporting vaccines as moderately safe to not safe (26.62% [292/1097] vs 18.57% [324/1745]), partially or not at all up-to-date vaccination status of youngest child (22.06% [242/1097] vs 9.57% [167/1745]), and difficulty in making the decision to vaccinate their youngest child (21.06% [231/1097] vs 10.09% [176/1745]). Out of the Web-based respondents who reported reasons for the difficulties in deciding to vaccinate, 37.2% (83/223) reported lack of knowledge or trust due to conflicting information and 23.8% (53/223) reported the perception of the risk of the adverse effects of vaccines being higher than the risk of disease acquisition.

Conclusions

We successfully recruited a large sample of our target population at low cost and achieved a high survey completion rate using Facebook. When compared with the RDD sampling strategy, we reached more vaccine-hesitant parents and younger parents with younger children—a population more likely to be making decisions on childhood immunizations. Facebook is a promising economical modality for reaching vaccine-hesitant parents for studies on the determinants of vaccine uptake.

Explanations for Not Receiving the Seasonal Influenza Vaccine: An Ontario Canada Based Survey

Despite evidence of the importance of the seasonal influenza vaccine for both individual and population health, only a third of the Ontario population received the vaccine in 2013/2014. The objective of this study was to identify why Ontarians are not getting the seasonal influenza vaccine. Written responses to the question "Why didn't you get the seasonal flu vaccine in the last flu season?" were deductively analyzed using the Conceptual Model of Vaccine Hesitancy. Inductive coding was also conducted to identify explanations that fall outside of the present model and may be unique to the seasonal influenza vaccine. Data were collected between August and early September, 2014 through a survey in the Region of Waterloo, Ontario. Overall, 91.4% of responses could be explained using the conceptual model and specifically relate to perceived importance of vaccination (46.8%), moral convictions (19.4%), and past experiences with vaccinations services (14.5%). Notably, explanations related to healthcare professional attitudes, risk perceptions and trust, and subjective norms were identified to a much lesser extent than those discussed above. The remaining 8.6% of responses cannot be explained by the model because they do not relate to hesitancy. Our data contribute to the minimal body of Canadian research investigating low uptake of the seasonal flu vaccine, adding to an evidence-base upon which to inform promotional campaigns. Our data also highlight the utility of the Conceptual Model of Vaccine Hesitancy for the design and analysis of research investigating seasonal flu vaccine refusal or delay.

Barriers of Influenza Vaccination Intention and Behavior - A Systematic Review of Influenza Vaccine Hesitancy, 2005 - 2016

BACKGROUND

Influenza vaccine hesitancy is a significant threat to global efforts to reduce the burden of seasonal and pandemic influenza. Potential barriers of influenza vaccination need to be identified to inform interventions to raise awareness, influenza vaccine acceptance and uptake.

OBJECTIVE

This review aims to (1) identify relevant studies and extract individual barriers of seasonal and pandemic influenza vaccination for risk groups and the general public; and (2) map knowledge gaps in understanding influenza vaccine hesitancy to derive directions for further research and inform interventions in this area.

METHODS

Thirteen databases covering the areas of Medicine, Bioscience, Psychology, Sociology and Public Health were searched for peer-reviewed articles published between the years 2005 and 2016. Following the PRISMA approach, 470 articles were selected and analyzed for significant barriers to influenza vaccine uptake or intention. The barriers for different risk groups and flu types were clustered according to a conceptual framework based on the Theory of Planned Behavior and discussed using the 4C model of reasons for non-vaccination.

RESULTS

Most studies were conducted in the American and European region. Health care personnel (HCP) and the general public were the most studied populations, while parental decisions for children at high risk were under-represented. This study also identifies understudied concepts. A lack of confidence, inconvenience, calculation and complacency were identified to different extents as barriers to influenza vaccine uptake in risk groups.

CONCLUSION

Many different psychological, contextual, sociodemographic and physical barriers that are specific to certain risk groups were identified. While most sociodemographic and physical variables may be significantly related to influenza vaccine hesitancy, they cannot be used to explain its emergence or intensity. Psychological determinants were meaningfully related to uptake and should therefore be measured in a valid and comparable way. A compendium of measurements for future use is suggested as supporting information.

Factors associated with influenza vaccination coverage among the elderly in South Korea: the Fourth Korean National Health and Nutrition Examination Survey (KNHANES IV)

OBJECTIVE

The annual outbreak of influenza is one of the major causes of morbidity and mortality among the elderly population around the world. While there is an annual vaccine available to prevent or reduce the incidence of disease, not all older people in Korea choose to be vaccinated. There have been few previous studies to examine the factors influencing influenza vaccination in Korea. Thus, this study identifies nationwide factors that affect influenza vaccination rates in elderly Koreans.

METHODS

We obtained data from the Fourth Korean National Health and Nutrition Examination Survey 2007-2009 (KNHANES IV), a nationwide health survey in Korea. To assess influenza vaccination status, we analysed answers to a single question from the survey. From the respondents, we selected 3567 elderly population aged 65 years or older, to analyse the effects of variables including sociodemographic, health behavioural risk, health status and psychological factors on vaccination coverage. We identified factors that affect vaccination status using a multiple logistic regression analysis.

RESULTS

The rate of influenza vaccination in this elderly population was 75.8%. Overall, the most significant determinants for choosing influenza vaccination were a recent history of health screening (adjusted OR (aOR) 2.26, 95% CI 1.92 to 2.66) and smoking (aOR 0.78, 95% CI 0.62 to 0.98). Other contributing factors were age, household income, marital status, alcohol consumption, physical activity level, self-reported health status and a limitation in daily activities. In contrast, psychological factors, including self-perceived quality of life, stress and depressive mood, did not show close association with vaccination coverage.

CONCLUSIONS

To boost influenza vaccination rates in the elderly, an influenza campaign should focus on under-represented groups, especially smokers. Additionally, promoting routine health screening for the elderly may be an efficient way to help achieve higher vaccination rates. Our results highlight the need for a new strategy for the vaccination campaign.

Persistent racial and ethnic disparities in flu vaccination coverage: Results from a population-based study

BACKGROUND

The Advisory Committee on Immunization Practices recommends annual flu vaccination for all adults. We aimed to identify predictors of receiving a flu vaccination, with an emphasis on the impact of race and ethnicity.

METHODS

We used data from the 2011-2012 California Health Interview Survey and included all individuals aged ≥18 years. We performed a survey-weighted logistic regression on receipt of flu vaccination within the last year, adjusted by demographic and socioeconomic variables, and calculated odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Our study included a population-weighted sample of 27,796,484 individuals. Overall, 35.8% received a flu vaccination within the last year. Blacks were 33% less likely (95% CI, 21%-43%) to have been vaccinated than whites. Conversely, Koreans (OR, 1.77; 95% CI, 1.35-2.33) and Vietnamese (OR, 1.57; 95% CI, 1.19-2.07) were more likely than whites to have been vaccinated. No differences were seen between whites and the remaining racial and ethnic groups (Latino, Japanese, Chinese, Filipino, South Asian, Asian other, and other).

CONCLUSIONS

Racial and ethnic disparities in flu vaccination uptake exist in California. Namely, blacks have lower vaccination rates than whites, and there are disparate vaccination rates among the Asian-American subgroups. Efforts to increase vaccination rates among these groups are needed.

Impact of pharmacist administration of influenza vaccines on uptake in Canada

BACKGROUND

Uptake of influenza vaccination in Canada remains suboptimal despite widespread public funding. To increase access, several provinces have implemented policies permitting pharmacists to administer influenza vaccines in community pharmacies. We examined the impact of such policies on the uptake of seasonal influenza vaccination in Canada.

METHODS

We pooled data from the 2007-2014 cycles of the Canadian Community Health Survey (n = 481 526). To determine the impact of influenza vaccine administration by pharmacists, we estimated the prevalence ratio for the association between the presence of a pharmacist policy and individual-level vaccine uptake using a modified Poisson regression model (dependent variable: vaccine uptake) with normalized weights while controlling for numerous health and sociodemographic factors.

RESULTS

Across all survey cycles combined, 28.8% of respondents reported receiving a seasonal influenza vaccine during the 12 months before survey participation. Introduction of a policy for pharmacist administration of influenza vaccine was associated with a modest increase in coverage (2.2%) and an individual's likelihood of uptake (adjusted prevalence ratio 1.05, 95% confidence interval 1.02-1.08).

INTERPRETATION

Uptake of influenza immunization was modestly increased in Canadian jurisdictions that allowed pharmacists to administer influenza vaccines.

Vaccine-preventable disease-related hospitalization among immigrants and refugees to Canada: Study of linked population-based databases

While immigrants tend to be healthier especially when they first arrived, this healthy immigrant effect may not apply to vaccine-preventable diseases (VPD) especially among immigrants from countries without vaccination programs. There is therefore an important information gap regarding differential health outcome and hospitalization usage by immigrant status, landing cohort, world region and immigrant category. This study focused on acute-care hospitalization, and used two recently linked population-based databases in Canada, namely, the 2006 Census linked to the Hospital Discharge Abstract (DAD), and the Immigrant Landing File linked to the DAD (ILF-DAD) to estimate crude and age-standardized VPD-related hospitalization rates (ASHR) by the above-mentioned immigrant characteristics to be compared with that for overall Canadian-born reference population. Based on the 2006 Census-DAD linked database, VPD-specific ASHR for overall immigrants was significantly higher than that for the Canadian-born population (1.6, 95% CI, 1.5, 1.6 vs 1.2, 95% CI, 1.1, 1.2, respectively). VPD-specific ASHRs by landing cohorts also increased with years in Canada (e.g. 1.4, 95% CI, 1.3, 1.5 for the 1990-2006 cohort, and 1.6, 95% CI, 1.5, 1.7 for the pre-1980 cohort). Based on the 1980-2006 ILF-DAD, the VPD-specific ASHRs were highest among Southeast and East Asians (e.g. 2.1, 95% CI, 1.9, 2.3 for East Asia). Compared with the Canadian-born, economic class immigrants overall had significantly lower ASHR (1.4, 95% CI 1.2, 1.6), but the low rate was mainly due to the dependants (spouse or children) within this class (0.8, 95% CI 0.6, 1.1). Both family and refugee categories had significantly higher ASHRs (1.3, 95% CI, 1.2, 1.5 and 1.7, 95% CI, 1.4, 2.1, respectively), especially among those refugees assisted by government (2.0, 95% CI, 1.4, 2.6). With increasing immigration, changing source countries and emerging needs for refugee settlements in Canada, these newly linked datasets help to monitor VPD-related hospitalization pattern among Canadian immigrants.

Influenza immunization among Canadian health care personnel: a cross-sectional study

BACKGROUND

Influenza immunization coverage among Canadian health care personnel remains below national targets. Targeting this group is of particular importance given their elevated risk of influenza infection, role in transmission and influence on patients' immunization status. We examined influenza immunization coverage in health care personnel in Canada, reasons for not being immunized and the impact of "vaccinate-or-mask" influenza prevention policies.

METHODS

In this national cross-sectional study, we pooled data from the 2007 to 2014 cycles of the Canadian Community Health Survey and restricted it to respondents who reported a health care occupation. Using bootstrapped survey weights, we examined immunization coverage by occupation and by presence of vaccinate-or-mask policies, and reasons for not being immunized. We used modified Poisson regression to estimate the prevalence ratio (PR) of influenza immunization for health care occupations compared with the general working population.

RESULTS

For all survey cycles combined, 50% of 18 446 health care personnel reported receiving seasonal influenza immunization during the previous 12 months, although this varied by occupation type (range 4%-72%). Compared with the general working population, family physicians and general practitioners were most likely to be immunized (PR 3.15, 95% confidence interval [CI] 2.76-3.59), whereas chiropractors, midwives and practitioners of natural healing were least likely (PR 0.17, 95% CI 0.10-0.30). Among those who were not immunized, the most frequently cited reason was the belief that influenza immunization is unnecessary. Introduction of vaccinate-or-mask policies was associated with increased influenza immunization among health care personnel.

INTERPRETATION

Health care personnel are more likely to be immunized against influenza than the general working population, but coverage remains suboptimal overall, and we observed wide variation by occupation type. More efforts are needed to target specific health care occupations with low immunization coverage.

Trends in influenza vaccine coverage and vaccine hesitancy in Canada, 2006/07 to 2013/14: results from cross-sectional survey data

BACKGROUND

Past studies have reported influenza vaccination coverage below national targets, but up-to-date estimates are needed to understand trends and to identify areas for intervention. The objective of this study was to describe recent trends in influenza vaccination in Canada, timing of uptake and reasons for not receiving the vaccine.

METHODS

We pooled data from the 2007 to 2014 cycles of the Canadian Community Health Survey. Using bootstrapped survey weights, we examined influenza vaccine coverage by various groups, including by age and by presence of chronic medical conditions.

RESULTS

The overall sample included 481 526 respondents. Across all survey cycles combined, 29% of respondents reported receiving seasonal influenza vaccination in the past 12 months. Coverage levels were fairly consistent during the study period, but varied by province or territory. Vaccination coverage decreased over time among those aged 65 years and older. Among those who received a vaccination, it was most common to do so in October or November. Among those not vaccinated, the most frequently cited reason was believing it was unnecessary.

INTERPRETATION

Influenza vaccination coverage continues to fall below national targets, with substantial declines seen among those aged 65 years and older, a group for which vaccination is particularly important. More intensive efforts are needed to improve coverage in Canada, particularly for high-risk groups.

The coexistence or replacement of two subtypes of influenza

A pandemic subtype of influenza A sometimes replaces but sometimes coexists with the previous seasonal subtype. For example, the 1957 pandemic subtype H2N2 replaced the seasonal subtype H1N1; whereas after 1977 subtypes H1N1 (from the pandemic) and H3N2 continue to coexist. In an attempt to understand these alternatives, a hybrid model for the dynamics of influenza A is formulated. During an epidemic season the model takes into account cross-immunity of strains depending on the most recent seasonal infection. This cross-immunity reduces susceptibility to related strains of the seasonal subtype, and wanes with time due to virus drift. The population is assumed to reach an equilibrium distribution in susceptibility after several seasons, and then a pandemic subtype appears. Individuals who have been infected by the seasonal subtype all have the same cross-immunity to the pandemic subtype. A combination of theoretical and numerical analyses shows that for very strong cross-immunity between the subtypes the pandemic cannot invade, whereas for strong and weak cross-immunity there is coexistence for the season following the pandemic, and for intermediate levels of cross-immunity the pandemic may replace the seasonal subtype. This replacement depends on the basic reproduction numbers of seasonal and pandemic influenza. Vaccination against the seasonal subtype is found to slightly increase this range for pandemic replacement, with the range increasing with increasing vaccine protection and with the length of time that vaccine-induced immunity lasts.

Influenza immunization in Canada's low-income population

BACKGROUND

Immunization offers the best protection from influenza infection. Little evidence describes disparities in immunization uptake among low-income individuals. Higher rates of chronic disease put this population at increased risk of influenza-related complications. This analysis examines if the type of main source of household income in low-income groups affects influenza immunization uptake. We hypothesized that individuals on social assistance have less access to immunization compared to those with employment earnings or seniors' benefits.

METHODS

Data was obtained from the Canadian Community Health Survey annual component 2009-2010. A total of 10,373 low-income respondents (<20,000$ Canadian per annum) were included. Logistic regression, stratified according to type of provincial publicly funded immunization program, was used to examine the association between influenza immunization (in the last 12 months) and main source of household income (employment earnings; social assistance as a combination of employment insurance or worker's compensation or welfare; or seniors' benefits).

RESULTS

Overall, 32.5% of respondents reported receiving influenza immunization. In multivariable analysis of universal publicly funded influenza immunization programs, those reporting social assistance (AOR 1.24, 95% CI 1.02-1.51) or seniors' benefits (AOR 1.56, 95% CI 1.23-1.98) were more likely to be immunized compared to those reporting employment earnings. Similar results were observed for high-risk programs.

CONCLUSIONS

Among the low-income sample, overall influenza immunization coverage is low. Those receiving social assistance or seniors' benefits may have been targeted due to higher rates of chronic disease. Programs reaching the workforce may be important to attain broader coverage. However, CCHS data was collected during the H1N1 pandemic influenza, thus results may not be generalizable to influenza immunization in non-pandemic years.

The challenges of sustaining measles elimination in Canada

Recent importations of measles into Canada have not generally led to large outbreaks, indicating that measles is well controlled in Canada. Isolated large outbreaks that have occurred remind us of the need to remain vigilant. Measles presents particular challenges because it is the most infectious disease known, it thrives among those who do not access the child health system for one reason or another, and we do not always have the information we need to identify and target communities with low immunization coverage. Outbreaks typically arise from Canadians who travel and are exposed to measles abroad. Controlling sporadic outbreaks arising from importations is time and resource intensive, which makes immunization for Canadians travelling outside the region of the Americas (where measles has been eliminated) a priority. To prevent importations of measles into Canada altogether requires other countries and regions of the world to make progress in eliminating measles.

Ethnic disparities in acquiring 2009 pandemic H1N1 influenza: a case-control study

BACKGROUND

Novel risk factors were associated with the 2009 pandemic A/H1N1 virus (pH1N1). Ethnicity was among these risk factors. Ethnic disparities in hospitalization and death due to pH1N1 were noted. The purpose of this study is to determine whether there are ethnic disparities in acquiring the 2009 pandemic H1N1.

METHODS

We conducted a test-negative case-control study of the risk of pH1N1 infection using data from Ontario, Canada. Cases were laboratory confirmed to have influenza using reverse-transcriptase polymerase chain reaction (RT-PCR), and controls were obtained from the same population and were RT-PCR negative. Multivariate logistic regression was used to determine the association between ethnicity and pH1N1 infection, while adjusting for demographic, clinical and ecological covariates.

RESULTS

Adult cases were more likely than controls to be self-classified as East/Southeast Asian (OR = 2.59, 95% CI 1.02-6.57), South Asian (OR = 6.22, 95% CI 2.01-19.24) and Black (OR = 9.72, 95% CI 2.29-41.27). Pediatric cases were more likely to be self-identified as Black (OR = 6.43, 95% CI 1.83-22.59). However, pediatric cases without risk factors for severe influenza infection were more likely to be South Asian (OR 2.92, 95% CI 1.11-7.68), Black (OR 16.02, 95% CI 2.85-89.92), and West Asian/Arab, Latin American or Multi-racial groups (OR 3.09 95% CI 1.06-9.00).

CONCLUSIONS

pH1N1 cases were more likely to come from certain ethnic groups compared to test-negative controls. Insights into whether these disparities arise due to social or biological factors are needed in order to understand what approaches can be taken to reduce the burden of a future influenza pandemic.

The effect of physicians' awareness on influenza and pneumococcal vaccination rates and correlates of vaccination in patients with diabetes in Turkey: an epidemiological Study "diaVAX"

We aimed to examine the effect of increased physician awareness on the rate and determinants of influenza and pneumococcal vaccinations in diabetic patients. Diabetic patients (n = 5682, mean [SD] age: 57.3 [11.6] years, 57% female) were enrolled by 44 physicians between Sept 2010 and Jan 2011. The physicians were initially questioned regarding vaccination practices, and then, they attended a training program. During the last five years, the physicians recommended influenza and pneumococcal vaccinations to 87.9% and 83.4% of the patients, respectively; however; only 27% of the patients received the influenza and 9.8% received the pneumococcal vaccines. One year after the training, the vaccination rates increased to 63.3% and 40.7%, respectively. The logistic regression models revealed that variables which increased the likelihood of having been vaccinated against influenza were: longer duration of diabetes, presence of hyperlipidemia and more use of concomitant medications whereas more use of anti-hyperglycemic medications was associated with increased odds of vaccination. On the other hand, older age, longer duration of diabetes and presence of a cardiovascular disease were variables which decreased the likelihood of having been vaccinated against pneumococcal disease during the past five years. However, during the study period, variables which decreased the odds of having been vaccinated included: older age and anti-hyperglycemic medications for influenza, and presence of hyperlipidemia and a family history of hypertension for pneumococcal disease. While variables which increased the likelihood of vaccination in the same period were: increased number of co-morbidities for influenza, and family history of diabetes for pneumococcal disease. We conclude that increased awareness of physicians may help improve vaccination rates against influenza and pneumococcal disease. However, diabetic patients with more severe health conditions are less likely to having been vaccinated. More structural/systematic vaccination programs are needed to increase the vaccination rates in patients with diabetes.

Safety, immunogenicity, and tolerability of three influenza vaccines in older adults: results of a randomized, controlled comparison

To determine if newer influenza vaccines can safely improve seroprotection rates of older adults, we compared three licensed trivalent inactivated vaccines (TIVs) in a randomized, controlled trial with evaluator blinding. Participants were non-frail adults ≥ 65 y old, annually TIV-immunized. Study vaccines included intradermal (IDV), MF59-adjuvanted (ADV) and subunit (TIV) formulations of equal potency and strain composition. Blood was obtained before vaccination (V1) and 21 (V2) and 180 d (V3) afterward and tested by hemagglutination inhibition (HAI) assay. Safety diaries were completed daily by participants and specific tolerability questions were posed regarding injections and symptoms. In total, 911 participants were immunized and 887 (97.4%) completed V3. Groups had similar demographics. General symptom rates post-vaccination were similar among groups. Rates of injection site redness after IDV/ADV/TIV were 75%/13%/13% and rates of pain were 29%/38%/20%, respectively, but each vaccine was well tolerated, with symptoms causing little bother. Baseline antibody titers did not differ significantly among groups but B/Brisbane titers were too high for meaningful response assessments. At V2, seroprotection rates (HAI titer ≥ 40) were highest after ADV, the rate advantage over IDV and TIV being significant at 11.8% and 11.4% for H3N2 and 10.2% and 12.5% for H1N1, respectively. At day 180, seroprotection rates had declined ~25% and no longer differed significantly among groups. While IDV and TIV were also well tolerated, ADV induced modestly higher antibody titers in seniors to influenza A strains at 3 weeks but not 6 mo post-vaccination. Immune responses to IDV and TIV were similar in this population.