HPV Vaccine utilization, Alberta 2008/09-2013/14 School year

Factors influencing human papillomavirus school-based immunization in Alberta: A mixed-methods study protocol

More than 1,300 Canadians are diagnosed with cervical cancer annually, which is nearly preventable through human papillomavirus (HPV) immunization. Across Canada, coverage rates remain below the 90% target set out by the Action Plan for the Elimination of Cervical Cancer in Canada (2020-2030). To support this Plan, the Canadian Partnership Against Cancer has commissioned the Urban Public Health Network (UPHN) to coordinate a quality improvement project with Canada's school-based HPV immunization programs. In Alberta, the UPHN partnered with Alberta Health Services (AHS) for this work. This study has one overarching research question: what are parent/guardian and program stakeholder perceived barriers, enablers and opportunities to immunization for youth as part of the school-based HPV immunization program in Alberta? This study uses a mixed-methods sequential explanatory design. A survey will be emailed to a sample of Albertans with children aged 11-17 years. Questions will be based on a Conceptual Framework of Access to Health Care. Subsequent qualitative work will explore the survey's findings. Parents/guardians identifying as vaccine hesitant in the survey will be invited to participate in virtual, semi-structured, in-depth interviews. Stakeholders of the school-based immunization program will be purposively sampled from AHS' five health zones for virtual focus groups. Quantitative data will be analyzed using SAS Studio 3.6 to carry out descriptive statistics and, using logistic regression, investigate if Framework constructs are associated with parents'/guardians' decision to immunize their children. Qualitative data will be analyzed using NVivo 12 to conduct template thematic analysis guided by the Framework. Study results will provide insights for Alberta's public health practitioners to make evidence-informed decisions when tailoring the school-based HPV immunization program to increase uptake in vaccine hesitant populations. Findings will contribute to the national study, which will culminate in recommendations to increase HPV immunization uptake nationally and progress towards the 90% coverage target.

Distribution of HPV genotypes among women with abnormal cytology results in Alberta, Canada

BACKGROUND

Persistent infection with a subset of human papillomavirus (HPV) genotypes can cause abnormal cytology and invasive cervical cancer. This study examines the circulating HPV genotype strains in a local population of the province of Alberta (a largely unvaccinated population) to establish baseline frequency of vaccine and non-vaccine genotypes causing abnormal cervical cytology.

METHOD

Remnant liquid-based cytology specimens from the Alberta Cervical Cancer Screening Program (March 2014-January 2016) were examined. Only specimens from women who had a cytology grading of atypical squamous cells of undetermined significance or higher were included. HPV genotype was determined for all samples, and results were stratified by demographics and cytology results.

RESULTS

Forty-four unique HPV genotypes were identified from 4,794 samples. Of the 4,241 samples with a genotype identified, the most common genotypes were HPV 16, 18, 31, and 51, with 1,599 (37.7%), 441 (12.2%), 329 (7.8%), and 354 (8.4%), respectively. HPV9 vaccine genotypes made up 73.2% of these genotyped samples. Compared with specimens in which HPV9 vaccine genotypes were not detected, those with a genotype covered by the HPV9 vaccine were from younger women (33 [interquartile range {IQR] 28 to 42] y versus 40 [IQR 32 to 51] y; p < 0.00001).

CONCLUSIONS

The baseline distribution of HPV genotypes in this largely unvaccinated population indicates that the HPV9 vaccine provides good protection from high-risk HPV infections. Determining the frequency of genotypes causing abnormal cytology in this population post-vaccine implementation will be important to assess efficacy of vaccination and monitor for any potential genotype replacement.

Review of Evidence and Recommendation for Human Papillomavirus (HPV) Vaccination of Canadian Males Over the Age of 26 Years

Human papillomavirus (HPV) remains the most common sexually transmitted infection with a lifetime incidence of over 75%. Based on US data from the Centers for Disease Control and Prevention (CDC), 64% of invasive HPV-associated cancers are attributable to HPV 16 or 18 (65% for females; 63% males) and may be prevented by vaccination with either the quadrivalent or nonavalent HPV vaccine. Public HPV vaccination programs are now the norm for women aged 9-45 years and men aged 9-26 years in Canada. Yet, only recently have guidelines begun to consider vaccination of men older than 26 years of age. There now exist compelling reasons to recommend vaccination against HPV amongst males >26 years of age. Recognizing that the risks posed by HPV infection persist beyond 26 years of age, that the vaccination of men aged 26-45 years with HPV vaccine confers immunogenicity at levels demonstrably efficacious against HPV-related diseases, and that the Food and Drug Administration recently expanded the HPV vaccination to include older men, it is argued that HPV vaccination in men older than 26 years of age should be routinely recommended.

Identification of adenovirus species in Iranian pediatric population with severe acute respiratory infections

Aim: In this study we aimed to find the rate of human adenovirus (HAdV) infections and identify HAdVs molecular epidemiology in children younger than 5 years old with clinical diagnosis of severe acute respiratory infections in Iran. Patients & methods: A semi-nested PCR with in-house designed primers for HAdV was performed on 200 oropharyngeal swabs collected within 5 days from the onset of symptoms. The positive samples were subjected to sequencing and a phylogenetic tree was drawn. Results: Out of 200 specimens, 71 (35.5%) cases were positive for HAdVs. Detected strains matched with HAdV species B (80.3%), C (15.5%), D (2.8%) and E (1.8%). HAdV- B14/55 and HAdV-B3 were the most prevalent types, respectively. Conclusion: This study showed that infections with HAdV species B, were common in children, who were clinically diagnosed as severe acute respiratory infection cases in Iran. The results could be useful for future epidemiological researches.

A National Survey of Canadian Adults on HPV: Knowledge, Attitudes, and Barriers to the HPV Vaccine

OBJECTIVE

Identifying human papillomavirus (HPV) vaccination motivators and barriers among adults could lead to new approaches to improve HPV vaccination rates in non-pediatric populations. This Canadian survey aimed to assess current knowledge of, attitudes towards, and barriers to the HPV vaccine among the general public.

METHODS

An online panel was used to survey HPV unvaccinated women (n = 802) and vaccinated women (n = 250) 18 to 45 years old, as well as 18- to 26-year-old men (n = 200), in May and June 2016. A 16-item questionnaire collected data on sociodemographic factors, health-seeking behaviours, knowledge of HPV infection and its consequences, and the HPV vaccine. Data were stratified by sex and by vaccination status among women.

RESULTS

The majority of individuals somewhat or strongly agreed that vaccination is an important aspect of disease prevention (vaccinated women, 93%; unvaccinated women, 85%; and men, 59%). However, a high proportion of patients were concerned about vaccine safety (vaccinated women, 26%; unvaccinated women, 40%; and men, 36%). Moreover, 58% to 61% of participants were generally cautious about taking any vaccine. The number one reported barrier to vaccination was not having a recommendation from a doctor (38%). Cost was seen as a barrier by only 18% to 20% of participants.

CONCLUSION

Canadian participants show a broad diversity in HPV knowledge and regarding barriers to vaccination. The youngest populations (vaccinated women and men) showed higher levels of knowledge regarding HPV.

A review of 65 years of human adenovirus seroprevalence

Introduction: Human adenovirus (HAdV)-derived vectors have been used in numerous pre-clinical and clinical trials during the last 40 years. Current research in HAdV-based vaccines focuses on improving transgene immunogenicity and safety. Because pre-existing humoral immunity against HAdV types correlate with reduced vaccine efficacy and safety, many groups are exploring the development of HAdV types vectors with lower seroprevalence. However, global seroepidemiological data are incomplete. Areas covered: The goal of this review is to centralize 65 years of research on (primarily) HAdV epidemiology. After briefly addressing adenovirus biology, we chronical HAdV seroprevalence studies and highlight major milestones. Finally, we analyze data from about 50 studies with respect to HAdVs types that are currently used in the clinic, or are in the developmental pipeline. Expert opinion: Vaccination is among the most efficient tools to prevent infectious disease. HAdV-based vaccines have undeniable potential, but optimization is needed and antivector immunity remains a challenge if the same vectors are to be administrated to different populations. Here, we identify gaps in our knowledge and the need for updated worldwide epidemiological data.

"One of the greatest medical success stories:" Physicians and nurses' small stories about vaccine knowledge and anxieties

In recent years, the Canadian province of Alberta experienced outbreaks of measles, mumps, pertussis, and influenza. Even so, the dominant cultural narrative maintains that vaccines are safe, effective, and necessary to maintain population health. Many vaccine supporters have expressed anxieties that stories contradicting this narrative have lowered herd immunity levels because they frighten the public into avoiding vaccination. As such, vaccine policies often emphasize educating parents and the public about the importance and safety of vaccination. These policies rely on health professionals to encourage vaccine uptake and assume that all professionals support vaccination. Health professionals, however, are socially positioned between vaccine experts (such as immunologists) and non-experts (the wider public). In this article, I discuss health professionals' anxieties about the potential risks associated with vaccination and with the limitations of Alberta's immunisation program. Specifically, I address the question: If medical knowledge overwhelmingly supports vaccination, then why do some professionals continue to question certain vaccines? To investigate this topic, I interviewed twenty-seven physicians and seven nurses. With stock images and small stories that interviewees shared about their vaccine anxieties, I challenge the common assumption that all health professionals support vaccines uncritically. All interviewees provided generic statements that supported vaccination and Alberta's immunisation program, but they expressed anxieties when I asked for details. I found that their anxieties reflected nuances that the culturally dominant vaccine narrative overlooks. Particularly, they critiqued the influence that pharmaceutical companies, the perceived newness of specific vaccines, and the limitations of medical knowledge and vaccine schedules.

Human Papillomavirus Vaccination Uptake in Canada: A Systematic Review and Meta-analysis

Human papillomavirus (HPV) is the most commonly sexually transmitted infection in the world and the primary cause of cervical cancer. Canada introduced publicly funded HPV vaccination programs in 2006. The objectives of this study are twofold and aim to (1) determine the levels and (2) examine the various factors influencing vaccine uptake among the general Canadian population. A literature search was conducted on seven databases, followed by screening, methodological quality review (using modified Newcastle-Ottawa Scale), and data extraction. Pooled meta-analysis and a subgroup analysis were conducted stratifying by a number of variables (age, sex, type of program, and method of payment) determined apriori. A total of 718 peer-reviewed articles were initially identified with 12 remaining after screening and underwent methodological quality review. HPV vaccination uptake in Canada varied from 12.40% (95% confidence interval [CI] 6.77–20.26) to 88.20% (95% CI 85.72–90.39). The pooled random effects model showed the HPV vaccination uptake to be 55.92% (95% CI 44.87–66.65). The subgroup analysis showed that vaccination uptake was 66.95% (95% CI 55.00–77.89) in participants ≤ 18 years as compared to 13.58% (95% CI 10.93–16.46) in participants > 18 years. Uptake for females was higher 57.23% (95% CI: 45.40–68.66) when compared to that of 47.01% (95% CI: 0.82–97.75) in males. HPV vaccine uptake among school-based programs was 69.62% (95% CI 57.27–80.68) as compared to 18.66% (95% CI 6.66–34.92) for community-based programs. Vaccination uptake for publicly funded programs was significantly higher 66.95% (95% CI 55.00–77.89) when compared to 13.58% (95% CI 10.92–16.46) for programs where participants had to pay out of pocket. To prevent infections and reduce the burden of HPV-related diseases (including cervical cancer), communities should be made aware and encouraged to vaccinate their children. There is a documented need to direct effort and focus interventions toward improving HPV vaccination uptake in Canada.

Effect of human papillomavirus vaccination on cervical cancer screening in Alberta

BACKGROUND

A school-based program with quadrivalent human papillomavirus (HPV) vaccination was implemented in Alberta in 2008. We assessed the impact of this program on Pap test cytology results using databases of province-wide vaccination and cervical cancer screening.

METHODS

We conducted a nested case-control study involving a cohort of women in Alberta born between 1994 and 1997 who had at least 1 Pap test between 2012 and 2015. Women with negative cytology results were controls. Women with low-grade (atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion) and high-grade (atypical squamous cells, cannot rule out a high-grade lesion; or high-grade squamous intraepithelial lesion) cervical abnormalities were cases. Exposure status was assigned according to records of HPV vaccination. Odds ratios (ORs) for abnormal cytology results by vaccination status were adjusted for neighbourhood income, laboratory service, rural versus urban residency, and age.

RESULTS

The total study population was 10 204. Adjusting for age, vaccinated women had a higher screening rate than unvaccinated women (13.0% v. 11.4%, p < 0.001). Among women who received full vaccination (≥ 3 doses), the adjusted OR for cervical abnormalities was 0.72 (95% confidence interval [CI] 0.63-0.82). For high-grade lesions, the adjusted OR was 0.50 (95% CI 0.30-0.85). With 2-dose HPV vaccination, the adjusted OR for cervical abnormalities was 1.08 (95% CI 0.84-1.38).

INTERPRETATION

Quadrivalent HPV vaccination significantly reduced high-grade cervical abnormalities but required 3 doses. Vaccination against HPV was associated with screening uptake. Population-based vaccination and screening programs should work together to optimize cervical cancer prevention.