Marilou Kiely

Seasonal influenza vaccination uptake in Quebec, Canada, 2 years after the influenza A(H1N1) pandemic.

BACKGROUND A decrease in seasonal influenza vaccine uptake was observed after the influenza A(H1N1) pandemic in 2009. The goal of our study was to assess seasonal influenza vaccine uptake in 2011-2012, 2 years after the influenza A(H1N1) pandemic mass immunization campaign and to identify the main reasons for having or not having received the vaccine. METHODS A telephone survey using random-digit dialing methodology was conducted. Case-weights were assigned to adjust for disproportionate sampling and for nonresponse bias. Descriptive statistics were generated for all variables. RESULTS Seasonal influenza vaccine uptake was 57% among adults aged ≥60 years, 35% among adults with chronic medical conditions, and 44% among health care workers. The main reasons given for having been vaccinated were to be protected from influenza and a high perceived susceptibility to influenza, whereas low perceived susceptibility to influenza and low perceived severity of influenza were the main reasons for not having been vaccinated. CONCLUSIONS An increase in seasonal influenza vaccine uptake was observed 2 years after the influenza A(H1N1) pandemic. However, vaccine coverage is still below the target level of 80%. More efforts are needed to develop effective strategies to increase seasonal influenza vaccine uptake.

Feasibility and impact of providing feedback to vaccinating medical clinics: evaluating a public health intervention

BackgroundVaccine coverage (VC) at a given age is a widely-used indicator for measuring the performance of vaccination programs. However, there is increasing data suggesting that measuring delays in administering vaccines complements the measure of VC. Providing feedback to vaccinators is recognized as an effective strategy for improving vaccine coverage, but its implementation has not been widely documented in Canada. The objective of this study was to evaluate the feasibility of providing personalized feedback to vaccinators and its impact on vaccination delays (VD).MethodsIn April and May 2008, a one-hour personalized feedback session was provided to health professionals in vaccinating medical clinics in the Quebec City region. VD for vaccines administered at two and twelve months of age were presented. Data from the regional vaccination registry were analysed for participating clinics. Two 12-month periods before and after the intervention were compared, namely from April 1st, 2007 to March 31st, 2008 and from June 1st, 2008 to May 31st, 2009.ResultsTen medical clinics out of the twelve approached (83%), representing more than 2500 vaccinated children, participated in the project. Preparing and conducting the feedback involved 20 hours of work and expenses of

Risk of Recurrence of Adverse Events Following Immunization: A Systematic Review

1000 per clinic. Based on a delay of one month, 94% of first doses of DTaP-Polio-Hib and 77% of meningococcal vaccine doses respected the vaccination schedule both before and after the intervention. Following the feedback, respect of the vaccination schedule increased for vaccines planned at 12 months for the four clinics that had modified their vaccination practices related to multiple injections (depending on the clinic, VD decreased by 24.4%, 32.0%, 40.2% and 44.6% respectively, p < 0.001 for all comparisons).ConclusionsThe present study shows that it is feasible to provide personalized feedback to vaccinating clinics. While it may have encouraged positive changes in practice concerning multiple injections, this intervention on its own did not impact vaccination delays of the clinics visited. It is possible that feedback integrated into other types of effective interventions and sustained over time may have more impact on VD.

Factors associated with HPV vaccination among adult women in Quebec.

This systematic review presents the risk of recurrence of AEFIs in patients who receive subsequent doses of vaccine. CONTEXT: Reimmunizing patients who had an adverse event following immunization (AEFI) is sometimes a challenge because there are limited data on the risk and severity of AEFI recurrence. OBJECTIVE: To summarize the literature on the risk of AEFI recurrence. DATA SOURCES: PubMed, Embase, and Cochrane library. STUDY SELECTION: We included articles in English or French published before September 30, 2016. Articles were selected if they estimated the risk of AEFI recurrence in at least 5 individuals. Studies with experimental vaccines were excluded. DATA EXTRACTION: Data on study design, setting, population, vaccines, and AEFI recurrence were extracted. RESULTS: Twenty-nine articles were included. Among patients with a history of hypotonic hyporesponsive episode (n = 398), anaphylaxis (n = 133), or seizures (n = 60) who were reimmunized, events recurred in 0% to 0.8%. Allergic-like events recurred in 30 of 594 reimmunized patients. Fever recurred in 0% to 84% of 836 reimmunized patients, depending on the vaccine and dose number. Among children with extensive limb swelling after the fourth dose of diphtheria-tetanus-acellular pertussis vaccine, recurrence was higher when the fifth dose was given withthe full-antigen formulation (78%) compared with the reduced-antigen formulation (53%, P = .02) LIMITATIONS: Many studies, included few patients, and those with severe AEFIs were often not reimmunized. CONCLUSIONS: Despite vaccines being administered to millions of people annually, there are few studies in which researchers evaluated AEFI recurrence. Published studies suggest that reimmunization is usually safe. However in these studies, severe cases were often not reimmunized.

Acceptability of live attenuated influenza vaccine by vaccine providers in Quebec, Canada

Background and objective: Human papillomavirus (HPV) infections are the most common sexually transmitted infections in North America and are associated with cervical cancer. A publicly-funded HPV immunization program was launched in the province of Quebec, Canada, in the fall of 2008. The aim of this study was to explore factors associated with HPV immunization among young adult women not targeted by this program. Methods: A questionnaire was mailed to 2400 24-y-old women randomly selected from the Quebec provincial health insurance database and 56% responded. Factors associated with vaccination status were analyzed using a multivariate logistic regression model. Results: Few women had received at least one dose of HPV vaccine among the 1347 respondents. Age at first sexual intercourse ≥ 20 y, participating in cervical cancer screening, higher education level, being born in Quebec and some positive beliefs about HPV were associated with vaccination. Conclusions: The rate of immunization in women who had to pay for the HPV vaccine was very low and was associated with characteristics that are generally associated with a lower risk for HPV infection and cervical cancer. Efforts are needed to reach at-risk adult women.

Investigation of an increase in large local reactions following vaccine schedule change to include DTaP-HB-IPV-Hib (Infanrix-hexa®) and MMRV (ProQuad®) at 18 months of age

A live attenuated influenza vaccine (LAIV) was offered during the 2012-13 influenza season in Quebec, Canada, to children aged between 2 and 17 years with chronic medical conditions. Despite the offer, uptake of the vaccine was low. We assessed the perceptions and opinions about seasonal influenza vaccination and LAIV use among vaccine providers who participated in the 2012-13 campaign. More than 70% of them thought that LAIV was safe and effective and more than 90% considered that the vaccine was well-received by parents and healthcare professionals. According to respondents, the most frequent concerns of parents about LAIV were linked to vaccine efficacy. LAIV is well-accepted by vaccine providers involved in influenza vaccination clinics, but more information about the vaccine and the recommendations for its use are needed to increase vaccine uptake.

Impact of the addition of new vaccines in the early childhood schedule on vaccine coverage by 24 months of age from 2006 to 2016 in Quebec, Canada

CONTEXT In 2015 in Quebec, Canada, the passive vaccine adverse event reporting system detected an increase in large local reactions associated with vaccines recommended at the 18-month visit. This followed changes to the pediatric vaccine schedule to include hexavalent diphtheria-tetanus-acellular-pertusis-inactivated polio-Haemophilus influenzae type b-hepatitis B vaccine (DTaP-IPV-Hib-HB, Infanrix-hexa®, GSK) and quadrivalent measles-mumps-rubella-varicella vaccine (MMRV, ProQuad®, Merck) as 18-month booster doses. OBJECTIVES To determine if the excess of large local reactions was caused by a specific vaccine or their co-administration in the same limb or during the same visit. METHODS A case-control study was conducted among cases born between January 2012 and April 2015 with a large local reaction following MMR ± V or DTaP-IPV-Hib ± HB vaccines administered between 16 and 23 months of age. Controls were randomly selected from the provincial medicare database among children born during the same period. RESULTS Our analysis included 96 cases and 494 controls vaccinated with MMRV or DTaP-IPV-Hib ± HB vaccines. Among the 96 cases, 46% had a cellulitis and 54% had an injection site reaction extending beyond the nearest joint and/or lasting ≥ 4 days. Among the 39 cases who were immunized in different limbs, 77% of the large local reactions were located at the Infanrix-hexa® site, 5% at the DTaP-IPV-Hib site and 18% at the ProQuad® site. Large local reactions were significantly more frequent with Infanrix-hexa® than with DTaP-IPV-Hib vaccine (OR 5.9 95% CI: 1.4-25.7). Administration of ProQuad® and Infanrix-hexa® in the same limb did not increase the risk of large local reactions. CONCLUSION This investigation suggested that most large local reactions were causally associated with the Infanrix-hexa® vaccine and that the risk was not greater when ProQuad® and Infanrix-hexa® were administered in the same limb. Given the improved vaccine coverage for hepatitis B, benefit-risk analysis likely still favours ongoing use of Infanrix-hexa® with informed parental consent.

Delayed measles vaccination of toddlers in Canada: Associated socio-demographic factors and parental knowledge, attitudes and beliefs

CONTEXT Between 2004 and 2016, in the province of Quebec (Canada), 4 new antigens were added in the early childhood vaccine schedule from birth to 18 months, increasing the number of injections or doses needed from 7 to 12. These additions may have decreased the proportion of children who had received all recommended vaccines. OBJECTIVES To assess the impact of the introduction of new vaccines to the childhood schedule on the 24-month vaccine coverage from 2006 to 2016 and identify factors associated with incomplete vaccination status by 24 months of age. METHODS We used the data from six cross-sectional vaccine coverage surveys conducted every two years which included a total of 3515 children aged 2 years old and randomly selected from the Quebec public health insurance database. Factors associated with an incomplete vaccine status by 24 months were identified with multivariable logistic regression. RESULTS Despite the addition of 4 new vaccine antigens since 2004, the vaccine coverage remained high from 2006 (82.4%) through 2016 (88.3%) for vaccines present in the schedule since 2006. In 2016, vaccine coverage was 78.2% for all vaccines included in the schedule. The vaccine coverage of new vaccines increases rapidly within 2 years of their introduction. For both new and older vaccines, incomplete vaccine status by 24 months of age is associated with a delay of 30 days or more in receiving the vaccines scheduled at 2 and 12 months of age. CONCLUSIONS Increasing to 12 the number of doses in the recommended schedule has slightly reduced the vaccine coverage by 24 months of age and the vaccine coverage of vaccines already in the schedule remained stable over the years. Future additions to the vaccine schedule may not be similarly accepted by the population and this will require continuing the monitoring of vaccine coverage.

Virus du papillome humain : connaissances, croyances et comportements des femmes québécoises

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