Summary of the NACI Supplemental Statement on Mammalian Cell Culture-Based Influenza Vaccines.

BACKGROUND: Mammalian cell culture-based technology is an innovative technique for influenza vaccine manufacturing that may be a valuable alternative to overcome some of the problems and vulnerabilities associated with conventional egg-based influenza vaccine production. Flucelvax® Quad (Seqirus, Inc.) is the first and only mammalian cell culture-based quadrivalent inactivated, subunit influenza vaccine (IIV4-cc) authorized for adult and pediatric use in Canada. The National Advisory Committee on Immunization (NACI) has not previously made a recommendation on cell culture-based influenza vaccines in any population. OBJECTIVE: To review the available evidence for the efficacy, effectiveness, immunogenicity, and safety of IIV4-cc, and to summarize the NACI recommendation regarding the use of Flucelvax Quad in Canada in adults and children. METHODS: A systematic literature review on the vaccine efficacy, effectiveness, immunogenicity and safety of IIV4-cc in persons four years of age and older was performed. The systematic review's methodology was specified a priori in a written protocol. The NACI evidence-based process was used to assess the quality of eligible studies, summarize and analyze the findings, and develop a recommendation regarding the use of Flucelvax Quad in adults and children. The proposed recommendation was then considered and approved by NACI in light of the available evidence. RESULTS: Thirteen eligible studies were included in the evidence synthesis. In the four observational studies that assessed vaccine effectiveness of IIV4-cc, there were some data indicating potentially improved protection against influenza compared to conventional egg-based quadrivalent inactivated influenza vaccines (IIV4) or trivalent inactivated influenza vaccine (IIV3), particularly against A(H3N2) virus infection. There was also some evidence that IIV4-cc may be more effective than egg-based trivalent or quadrivalent influenza vaccines against non-laboratory confirmed influenza-related outcomes, but there is insufficient evidence for laboratory-confirmed outcomes. Two randomized controlled trials assessed the immunogenicity and safety of IIV4-cc compared with mammalian cell culture-based trivalent inactivated, subunit influenza vaccine (IIV3-cc). The IIV4-cc was well-tolerated and the reported solicited local and systemic adverse events were generally mild to moderate in intensity, self-limited and did not precipitate sequelae. One clinical review of cases and six peer-reviewed randomized controlled trials (four in adults and two in children) that reported on the safety of IIV3-cc were included in the review. The evidence on immunogenicity and safety was consistent across these studies and showed that there was no significant difference in adults and children four years of age and older who had received IIV3-cc or an egg-based IIV3. CONCLUSION: NACI concluded that there is fair evidence (Grade B Evidence) that Flucelvax Quad is effective, safe, and has non-inferior immunogenicity to comparable vaccines, based on direct evidence in adults and children nine years of age and older. NACI recommends that Flucelvax Quad may be considered among the IIV4 offered to adults and children nine years of age and older (Discretionary NACI Recommendation).

Summary of the NACI systematic review and recommendation on the use of live attenuated influenza vaccine (LAIV) in HIV-infected individuals.

BACKGROUND: Annual influenza vaccination is recommended for all individuals six months of age and older, including those with HIV infection. Prior to this statement, the National Advisory Committee on Immunization (NACI) stated that live attenuated influenza vaccine (LAIV) was contraindicated for all individuals with HIV infection. The objective of this article is to update NACI's guidance on the use of LAIV for HIV-infected individuals. METHODS: A systematic literature review of the use of LAIV in individuals with HIV was undertaken. The Canadian Adverse Events Following Immunization Surveillance System was searched for reports of adverse events following vaccination with LAIV in HIV-infected individuals. NACI approved the revised recommendations. RESULTS: NACI concluded that LAIV is immunogenic in children with HIV, and available data suggest that it is safe, although data were insufficient to detect possible uncommon adverse effects. LAIV may be considered as an option for vaccination of children 2-17 years old who meet the following criteria: 1) receiving highly active antiretroviral therapy for at least four months; 2) CD4 count of 500/µL or greater if age 2-5 years, or of 200/µL or greater if age 6-17 years; and 3) HIV plasma RNA less than 10,000 copies/mL. LAIV remains contraindicated for adults with HIV because of insufficient data. Intramuscular influenza vaccination is considered the standard for children living with HIV by NACI and the Canadian Paediatric & Perinatal HIV/AIDS Research Group, particularly for those without HIV viral load suppression (i.e. plasma HIV RNA is 40 copies/mL or greater). However, if intramuscular (IM) vaccination is not accepted by the patient or substitute decision-maker, LAIV would be reasonable for children meeting the criteria listed above. CONCLUSION: LAIV may be considered as an option for annual vaccination of selected children with HIV.

Summary of the NACI Seasonal Influenza Vaccine Statement for 2020-2021.

BACKGROUND: Evidence on influenza vaccination is continually evolving. The National Advisory Committee on Immunization (NACI) provides annual recommendations to the Public Health Agency of Canada regarding the use of seasonal influenza vaccines. OBJECTIVE: To summarize NACI's recommendations regarding the use of seasonal influenza vaccines for the 2020-2021 influenza season and to highlight new and updated recommendations. METHODS: 1) To update wording on influenza vaccination of health care workers, NACI reassessed the evidence in the context of ethics and acceptability frameworks, in accordance with NACI's recently expanded mandate. 2) To provide recommendations on the use of live attenuated influenza vaccine (LAIV) in HIV-infected individuals, the Influenza Working Group developed a predefined search strategy to identify all eligible studies, then assessed the quality and summarized and analyzed the findings according to the NACI evidence-based process. NACI provided new recommendations based on assessment of the evidence. RESULTS: 1) NACI continues to recommend that health care workers and other care providers in facilities and community settings should be vaccinated annually against influenza and that this group be included among those particularly recommended to receive the influenza vaccine. 2) NACI concluded that LAIV is immunogenic in children with stable HIV infection; therefore, NACI newly recommends that LAIV may be considered as an option for children 2-17 years of age with stable HIV infection on highly active antiretroviral therapy and with adequate immune function. CONCLUSION: NACI continues to recommend that an age-appropriate influenza vaccine should be offered annually to anyone six months of age and older who does not have contraindications to the vaccine, with a focus on the groups for whom influenza vaccination is particularly recommended.

Evaluation of the ability of standardized supports to improve public health response to syndromic surveillance for respiratory diseases in Canada.

BACKGROUND: Despite widespread implementation of syndromic surveillance systems within public health agencies, previous studies of the implementation and use of these systems have indicated that the functions and responses taken in response to syndromic surveillance data vary widely according to local context and preferences. The objective of the Syndromic Surveillance Evaluation Study was to develop and implement standardized supports in local public health agencies in Ontario, Canada, and evaluate the ability of these supports to affect actions taken as part of public health communicable disease control programs. METHODS: Local public health agencies (LPHA) in Ontario, which used syndromic surveillance based on emergency department visits for respiratory disease, were recruited and randomly allocated to the study intervention or control group. The intervention group health agencies received standardized supports in terms of a standardized aberrant event detection algorithm and a response protocol dictating steps to investigate and assess the public health significance of syndromic surveillance alerts. The control group continued with their pre-existing syndromic surveillance infrastructure and processes. Outcomes were assessed using logbooks, which collected quantitative and qualitative information about alerts received, investigation steps taken, and public health responses. The study was conducted prospectively for 15 months (October 2013 to February 2015). RESULTS: Fifteen LPHAs participated in the study (n = 9 intervention group, n = 6 control group). A total of 1,969 syndromic surveillance alerts were received by all LPHAs. Variations in the types and amount of responses varied by LPHA, in particularly differences were noted by the size of the health unit. Smaller health units had more challenges to both detect and mount a response to any alerts. LPHAs in the control group were more likely to declare alerts to have public health significance and to initiate any action. Regression models using repeated measures showed an interaction between the year (Year 1 versus Year 2) and the intervention as well as an interaction between year and sustained nature of the alert. Both of these were linked to the control health units reporting more "watchful waiting". CONCLUSIONS: This study raises questions about the effectiveness of using standardized protocols to improve the performance of syndromic surveillance in a decentralized public health system. Despite efforts to create standardized protocols and engage public health agencies in the process, no significant differences in the effective use of syndromic alerts were observed beyond year 1. It also raises questions about the minimum capacity of the agency and minimum population size that are required for an effective response.

Canada's National Advisory Committee on Immunization: Celebrating 50 years.

Vaccines have saved more lives than any other innovation in modern medicine. National immunization committees play a vital role in the development of evidence-based recommendations for the use of vaccines. The present article describes the evolution and work of the National Advisory Committee on Immunization in Canada as the group marks its 50th anniversary. The article also provides insight into the future challenges that the committee is likely to face.

Les vaccins ont sauvé plus de vies que n'importe quelle autre innovation de la médecine moderne. Les comités nationaux d'immunisation jouent un rôle essentiel dans la préparation de recommandations fondées sur des données probantes relatives à l'utilisation des vaccins. Le présent article décrit l'évolution et le travail du Comité consultatif national de l'immunisation du Canada, qui célèbre son cinquantième anniversaire. Il contient également un aperçu des prochains défis que le comité devra probablement relever.

Validation of infant immunization billing codes in administrative data.

Ontario has a single payer provincial health insurance program. Administrative data may provide a potentially robust source of information for post-marketing vaccine studies. Vaccine-specific immunization billing codes were introduced in 2011. Our objective was to validate Ontario's universal health care administrative datasets to assess infant immunization status. Electronic medical record data from the Electronic Medical Record Administrative data Linked Database (EMRALD) was used as the reference standard to calculate performance characteristics of the Ontario Health Insurance Plan (OHIP) database vaccine-specific and general immunization codes for 4 primary infant immunizations: diphtheria, tetanus, acellular pertussis, inactivated polio, Haemophilus influenzae type B (DTaP-IPV-Hib) combination vaccine, pneumococcal conjugate vaccine, measles, mumps, rubella (MMR) vaccine, and meningococcal conjugate serogroup C vaccine. OHIP billing claims had specificity ranging from 81% to 92%, sensitivity 70% to 83%, positive predictive value (PPV) 97% to 99%, and negative predictive value (NPV) 13% to 46% for identifying the various specific vaccines in administrative data. For cohorts vaccinated in the new code introduction phase, using both the vaccine-specific and general codes had higher sensitivity than the vaccine-specific codes alone. In conclusion, immunization billing claims from administrative data in Ontario had high specificity and PPV, moderate sensitivity, and low NPV. This study identifies some of the applications of utilizing administrative data for post-marketing vaccine studies. However, limitations of these data decrease their utility for measuring vaccine coverage and effectiveness. Therefore, the establishment of a comprehensive and linkable immunization registry should be a provincial priority.

Assessing the relative timeliness of Ontario's syndromic surveillance systems for early detection of the 2009 influenza H1N1 pandemic waves.

OBJECTIVES: Building on previous research noting variations in the operation and perceived utility of syndromic surveillance systems in Ontario, the timeliness of these different syndromic systems for detecting the onset of both 2009 H1N1 pandemic (A(H1N1)pdm09) waves relative to laboratory testing data was assessed using a standardized analytic algorithm. METHODS: Syndromic data, specifically local emergency department (ED) visit and school absenteeism data, as well as provincial Telehealth (telephone helpline) and antiviral prescription data, were analyzed retrospectively for the period April 1, 2009 to January 31, 2010. The C2-MEDIUM aberration detection method from the US Centers for Disease Control and Prevention's EARS software was used to detect increases above expected in syndromic data, and compared to laboratory alerts, defined as notice of confirmed A(H1N1)pdm09 cases over two consecutive days, to assess relative timeliness. RESULTS: In Wave 1, provincial-level alerts were detected for antiviral prescriptions and Telehealth respiratory calls before the laboratory alert. In Wave 2, Telehealth respiratory calls similarly alerted in advance of the laboratory, while local alerts from ED visit, antiviral prescription and school absenteeism data varied in timing relative to the laboratory alerts. Alerts from syndromic data were also observed to coincide with external factors such as media releases. CONCLUSIONS: Alerts from syndromic surveillance systems may be influenced by external factors and variation in system operations. Further understanding of both the impact of external factors on surveillance data and standardizing protocols for defining alerts is needed before the use of syndromic surveillance systems can be optimized.

pH1N1 - a comparative analysis of public health responses in Ontario to the influenza outbreak, public health and primary care: lessons learned and policy suggestions.

BACKGROUND: Ontario's 36 Public Health Units (PHUs) were responsible for implementing the H1N1 Pandemic Influenza Plans (PIPs) to address the first pandemic influenza virus in over 40 years. It was the first under conditions which permitted mass immunization. This is therefore the first opportunity to learn and document what worked well, and did not work well, in Ontario's response to pH1N1, and to make recommendations based on experience. METHODS: Our objectives were to: describe the PIP models, obtain perceptions on outcomes, lessons learned and to solicit policy suggestions for improvement. We conducted a 3-phase comparative analysis study comprised of semi-structured key informant interviews with local Medical Officers of Health (n=29 of 36), and Primary Care Physicians (n=20) and in Phase 3 with provincial Chief-Medical Officers of Health (n=6) and a provincial Medical Organization. Phase 2 data came from a Pan-Ontario symposium (n=44) comprised leaders representing: Public Health, Primary Care, Provincial and Federal Government. RESULTS: PIPs varied resulting in diverse experiences and lessons learned. This was in part due to different PHU characteristics that included: degree of planning, PHU and Primary Care capacity, population, geographic and relationships with Primary Care. Main lessons learned were: 1) Planning should be more comprehensive and operationalized at all levels. 2) Improve national and provincial communication strategies and eliminate contradictory messages from different sources. 3) An integrated community-wide response may be the best approach to decrease the impact of a pandemic. 4) The best Mass Immunization models can be quickly implemented and have high immunization rates. They should be flexible and allow for incremental responses that are based upon: i) pandemic severity, ii) local health system, population and geographic characteristics, iii) immunization objectives, and iv) vaccine supply. CONCLUSION: "We were very lucky that pH1N1 was not more severe." Consensus existed for more detailed planning and the inclusion of multiple health system and community stakeholders. PIPs should be flexible, allow for incremental responses and have important decisions (E.g., under which conditions Public Health, Primary Care, Pharmacists or others act as vaccine delivery agents.) made prior to a crisis.

Management of tick bites and lyme disease during pregnancy.

Lyme disease results from the bite of a black-legged tick, populations of which have now become established in parts of Nova Scotia, southeastern Quebec, southern Ontario from the Thousand Islands through the geographic regions on the north shore of Lake Ontario and Lake Erie, southeastern Manitoba, and British Columbia's Lower Mainland, Fraser Valley, and Vancouver Island. It takes more than 24 hours of attachment to transfer the spirochete Borrelia burgdorferi to the bitten animal or human. The diagnosis of Lyme disease is primarily clinical, with early Lyme disease characterized by a skin lesion (erythema migrans, a bull's-eye rash), which expands out from the site of the tick bite, and is often accompanied by influenza-like symptoms, arthralgia, myalgia, and fever. These signs and symptoms can present anywhere from three to 30 days after the tick bite. The management of pregnant women with a tick bite or suspected Lyme disease should be similar to that of non-pregnant adults, except that doxycyline, the first line antibiotic of choice, should not be used in pregnant women because of risk of permanent tooth discolouration and possible impact on bone formation in the fetus. An algorithm for the management of tick bites in pregnancy is presented. Clinical, serological, and epidemiological studies have all failed to demonstrate a causal association between infection with B. burgdorferi and any adverse pregnancy outcomes regardless of whether maternal exposure occurs before conception or during pregnancy itself.

The use of syndromic surveillance for decision-making during the H1N1 pandemic: a qualitative study.

BACKGROUND: Although an increasing number of studies are documenting uses of syndromic surveillance by front line public health, few detail the value added from linking syndromic data to public health decision-making. This study seeks to understand how syndromic data informed specific public health actions during the 2009 H1N1 pandemic. METHODS: Semi-structured telephone interviews were conducted with participants from Ontario's public health departments, the provincial ministry of health and federal public health agency to gather information about syndromic surveillance systems used and the role of syndromic data in informing specific public health actions taken during the pandemic. Responses were compared with how the same decisions were made by non-syndromic surveillance users. RESULTS: Findings from 56 interviews (82% response) show that syndromic data were most used for monitoring virus activity, measuring impact on the health care system and informing the opening of influenza assessment centres in several jurisdictions, and supporting communications and messaging, rather than its intended purpose of early outbreak detection. Syndromic data had limited impact on decisions that involved the operation of immunization clinics, school closures, sending information letters home with school children or providing recommendations to health care providers. Both syndromic surveillance users and non-users reported that guidance from the provincial ministry of health, communications with stakeholders and vaccine availability were driving factors in these public health decisions. CONCLUSIONS: Syndromic surveillance had limited use in decision-making during the 2009 H1N1 pandemic in Ontario. This study provides insights into the reasons why this occurred. Despite this, syndromic data were valued for providing situational awareness and confidence to support public communications and recommendations. Developing an understanding of how syndromic data are utilized during public health events provides valuable evidence to support future investments in public health surveillance.

Perceived usefulness of syndromic surveillance in Ontario during the H1N1 pandemic.

BACKGROUND: Despite the growing popularity of syndromic surveillance, little is known about if or how these systems are accepted, utilized and valued by end users. This study seeks to describe the use of syndromic surveillance systems in Ontario and users' perceptions of the value of these systems within the context of other surveillance systems. METHODS: Ontario's 36 public health units, the provincial ministry of health and federal public health agency completed a web survey to identify traditional and syndromic surveillance systems used routinely and during the pandemic and to describe system attributes and utility in monitoring pandemic activity and informing decision-making. RESULTS: Syndromic surveillance systems are used by 20/38 (53%) organizations. For routine surveillance, laboratory, integrated Public Health Information System and school absenteeism data are the most frequently used sources. Laboratory data received the highest ratings for reliability, timeliness and accuracy ('very acceptable' by 92, 51 and 89%). Hospital/clinic screening data were rated as the most reliable and timely syndromic data source (50 and 43%) and ED visit data the most accurate (48%). During the pandemic, laboratory data were considered the most useful for monitoring the epidemiology and informing decision-making while ED screening and visit data were considered the most useful syndromic sources. CONCLUSIONS: End user perceptions are valuable for identifying opportunities for improvement and guiding further investments in public health surveillance.

Acute otitis media and its prevention by immunization: a survey of Canadian pediatricians' knowledge, attitudes and beliefs.

INTRODUCTION: Acute otitis media (AOM) is one of the most common bacterial infectious diseases among children and is a leading cause of child healthcare visits and antibiotic prescriptions. Few vaccines have the potential to prevent AOM. The newer pneumococcal conjugate vaccines (PCV) offer a larger spectrum of protection against AOM, as well as preventing severe diseases. The main aim of this study was to assess pediatricians' opinions regarding AOM and its prevention by immunization. RESULTS: Response rate was 50%. Around 60% of respondents estimated that more than 50% of their patients under the age of 3 years would suffer from at least one episode of AOM in the following year. Most respondents (79%) rated consequences of AOM as moderate. Almost all physicians (99%) considered the newer PCV as safe and effective. Most respondents considered their knowledge of the new vaccines was sufficient. More than 90% had a firm intention to recommend newer PCV to their patients. Perceived benefits of AOM prevention by immunization were: reduction of antibiotic administration and reduction of post-AOM complications. More than half of respondents (53%) considered the risk of adverse events as a barrier to AOM prevention by immunization. In multivariate analysis, the main determinant of pediatricians' intention to recommend newer PCV was perceived safety and efficacy of the vaccines (partial R2 = 0.40, p < 0.0001). DISCUSSION: Results of this survey show that AOM is perceived as an important health problem by paediatricians. Information about the increased protection against AOM offered by newer PCV should be disseminated to physicians. MATERIALS AND METHODS: A self-administered, anonymous, mail-based questionnaire based upon the Health Belief Model and the Analytical framework for immunization programs was sent to all 1,852 Canadian pediatricians.

Canadian family physicians' and paediatricians' knowledge, attitudes and practices regarding A(H1N1) pandemic vaccine.

BACKGROUND: One of the main determinants of public immunization success is health professionals' support and recommendations. Little is known about the physicians' level of support and intentions regarding A(H1N1) pandemic influenza vaccination. The aim of this survey was to document Canadian family physicians' and paediatricians' knowledge, attitudes and practices (KAP) as well as their intentions regarding A(H1N1) pandemic influenza vaccines right before the beginning of the largest immunization campaign in Canadian history. FINDINGS: A self-administered, anonymous, mail-based questionnaire was sent to a random sample of family physicians and to all paediatricians practicing in Canada. All 921 questionnaires received by October 29 2009 were included in the analysis. Between 72% and 92% of respondents agreed with the statements regarding vaccine safety, effectiveness and acceptability. More than 75% of respondents intended to recommend the A(H1N1) pandemic influenza vaccine to their patients and to get vaccinated themselves. The most significant factors associated with the intention to recommend A(H1N1) pandemic vaccines were physicians' intention to be vaccinated against influenza themselves and the perceived acceptability of the vaccine by the vaccinators. CONCLUSIONS: Most Canadian family physicians and paediatricians surveyed were supportive of the A(H1N1) pandemic influenza vaccination before its implementation and large media coverage.

Automated mortality surveillance in south-eastern Ontario for pandemic influenza preparedness.

BACKGROUND: The recent Canadian experience with pandemic H1N1 (pH1N1) influenza in 2009 highlighted the need for enhanced surveillance at local and regional levels to support evidence-based decision making by physicians and public health. We describe the rationale, methodology, and provide preliminary findings from the implementation of an automated Mortality Surveillance System (MSS) in the Kingston, Frontenac and Lennox & Addington (KFL&A) health unit. METHODS: The MSS utilized an automated web-based framework with secure data transfer. A data sharing agreement between the local Medical Officer of Health and the City of Kingston facilitated weekly updates of mortality data. Deaths due to influenza were classified using keywords in the cause of death and a phonetic algorithm to capture alternate spellings. Anomaly detection was modeled on the modified cumulative sum algorithm implemented in the Early Aberration Reporting System. RESULTS: Retrospective analysis of municipal mortality data over a 10-year period established baseline mortality rates in the region. MSS data monitored during the pH1N1 influenza season showed no significant impact on the burden or timing of mortality in the KFL&A health unit. CONCLUSION: Municipal data enabled surveillance of mortality in the KFL&A region with weekly updates. Other municipalities may participate in this surveillance project using the Kingston model without significant ongoing investment. Efforts to improve data quality at the physician and transcription level are ongoing. Integration of mortality data and other real-time data streams into an integrated electronic public health dashboard could provide decision-makers with timely information during public health emergencies.

Setting priorities for new vaccination programs by using public health officers and immunization managers opinions.

The objective of this work was to assess the opinions of public health professionals (PHPs) about routinely recommended and new vaccines, and to evaluate the feasibility of using a modified Basic Priority Rating System (BPRS) approach to prioritize new immunization programs. One hundred and thirty six PHPs were invited to participate in the survey and 101 responded. Ninty-eight percent of respondents agreed that "recommended vaccines are very useful" (mean score=9.5 out of 10). Between 47% and 100% of respondents agreed with statements about usefulness, safety, effectiveness and acceptability of seven new vaccines (mean scores 5.7-9.7). The highest BPRS scores were observed for MMRV (7.3), DTaP-IPV-HBV-Hib (7.0), and conjugate ACYW-135 (5.4), followed by HPV (4.8), HAV (4.4), rotavirus (1.6) and zoster vaccine (1.5%). The results demonstrate that PHPs perceive presently recommended vaccines as very useful tools in infection prevention. On the other hand, the perceived usefulness, safety, effectiveness, and acceptability of new vaccines are heterogeneous. This heterogeneity is indicative of the complexity of decision-making around implementation of new immunization programs and the need for tools facilitating program prioritization. The modified BPRS approach using survey responses to five statements on program usefulness, vaccine safety, effectiveness, and acceptance by vaccinators and the population is a simple, feasible and inexpensive method of prioritizing new immunization programs. The method we propose is flexible in choosing target groups and allows a large number of professionals to be involved in the decision-making process about new immunization programs.

Vaccination against human papillomavirus: a baseline survey of Canadian clinicians' knowledge, attitudes and beliefs.

We assessed Canadian obstetrician/gynaecologists', family physicians' and paediatricians' knowledge, attitudes, and beliefs about HPV infection and prevention, as well as factors associated with willingness to prescribe HPV vaccines. A self-administered, anonymous questionnaire was mailed to 2500 physicians. The participation rate was 51%. Overall, 95% of respondents indicated that the vaccine should be given to girls before the onset of sexual activity; 80% of respondents felt that the best age for an HPV vaccination program is <14 years; 88% of respondents intend to recommend HPV vaccines if they are publicly funded. Several predisposing, reinforcing, organizational, preventive activity and situational factors were independently associated with the intention to prescribe the HPV vaccines. Most physicians expect an important benefit from HPV vaccination and intend to prescribe HPV vaccines (86.7%). To achieve high rates of vaccination coverage, several modifiable factors should be taken in consideration during immunization program implementation.