Vaccination coverage among social and healthcare workers in ten countries of Samu-social international sites

BackgroundWe aim to determine the vaccination coverage of social and healthcare workers in International sites of Samusocial, providing emergency care to homeless people, and to assess factors associated with having received necessary doses at adulthood.MethodsData on immunization coverage of social and healthcare workers were provided by a cross-sectional survey, conducted from February to April 2015 among 252 Samusocial workers in 10 countries. Vaccination status and characteristics of participants were collected through a self-administered questionnaire. Prevalence rate ratio (PRR) of vaccination status was calculated using Poisson regression models.ResultsAmong 252 Samusocial social and health workers who felt a questionnaire, median age was 39 years, 42.1% were female, 88.9% were in contact with homeless beneficiaries (19.1% health workers). Overall, 90.1% of Samusocial staff felt adult vaccinations was useful and 70.2% wished to receive booster doses in future. Vaccination coverage at adulthood was satisfactory for diphtheria and poliomyelitis (96%), but low for influenza (20.8%), meningococcus (50.5%), hepatitis B (56.3%), yellow fever (58.1%), measles (81.3%) and pertussis (90.7%). The main reasons for not having received vaccination booster doses were forgetting the dates of booster doses (38.4%) and not having received the information (13.5%). In adjusted analysis, prevalence of up-to-date for vaccination schedule was 35% higher among health workers than among social workers (aPRR = 1.35, 95%CI: 1.01–1.82, P = 0.05) and was 56% higher among workers who had a documentary evidence of vaccination than in those who did not (aPRR = 1.56, 95%CI: 1.19–2.02, P = 0.001).ConclusionsThe Samusocial International workers vaccine coverage at adulthood was insufficient and disparate by region. It is necessary to strengthen the outreach of this staff and increase immunization policy for hepatitis B, diphtheria, tetanus, and measles, as well as for yellow fever, rabies and meningococcal ACYW135 vaccines in at risk regions.     

Determinants of under-immunization and cumulative time spent under-immunized in a Quebec cohort

BackgroundUnder-immunization refers to a state of sub-optimal protection against vaccine preventable diseases. Vaccine coverage for age may not capture intentional or non-intentional spacing of vaccines in the recommended provincial immunization guidelines. We aimed to identify factors associated with coverage and under-immunization and to determine the number of days during which children were under-immunized during their first 24 months of life.MethodsSecondary analysis of children ≤3 years recruited through active surveillance for gastroenteritis from three Quebec pediatric emergency departments from 2012 to 2014. Vaccination status for children at least 24 months of age was determined using provincial immunization guidelines. Cumulative days under-immunized were calculated for DTaP-VPI-Hib, PCV, MMR, and Men-C-C. Factors associated with up-to-date (UTD) status at 24 months of life and for under-immunization ≥6 months were analyzed using logistic regression.ResultsOf 246 eligible children, 180 (73%) were UTD by 24 months of life. The mean cumulative days under-immunized for MMR was 107 days, for PCV 209 days, for Men-C-C 145 days, and for DTaP-VPI-Hib 227 days. Overall, 149 children (60%) experienced delay for at least 1 vaccine. Factors associated with both an UTD status at 24 months and concurrently associated with being under-immunization ≥6 months, included timely initiation of immunization (OR = 5.85; 95% CI: 2.80–12.22) and (OR = 0.13; 95% CI: 0.07–0.24), failure to co-administer 18-month vaccines (OR = 0.15; 95% CI: 0.10–0.21) and (OR = 3.29; 95% CI: 2.47–4.39), and having a household with ≥3 children under 18 years ((OR = 0.50; 0.28–0.86) and (OR = 2.99; 1.45–6.22), respectively.ConclusionPaired with an unexpected low level of coverage at 24 months of life, the majority of our cohort also experienced a state of under-immunization for a least one vaccine. Estimates of coverage do not capture intentional or non-intentional gaps in protection from vaccine preventable illnesses. Timely preventive care should be prioritized.     

Provider communication and HPV vaccination: The impact of recommendation quality

BackgroundReceiving a healthcare provider's recommendation is a strong predictor of HPV vaccination, but little is known empirically about which types of recommendation are most influential. Thus, we sought to investigate the relationship between recommendation quality and HPV vaccination among U.S. adolescents.MethodsIn 2014, we conducted a national, online survey of 1495 parents of 11–17-year-old adolescents. Parents reported whether providers endorsed HPV vaccination strongly, encouraged same-day vaccination, and discussed cancer prevention. Using an index of these quality indicators, we categorized parents as having received no, low-quality, or high-quality recommendations for HPV vaccination. Separate multivariable logistic regression models assessed associations between recommendation quality and HPV vaccine initiation (≥1 dose), follow through (3 doses, among initiators), refusal, and delay.ResultsAlmost half (48%) of parents reported no provider recommendation for HPV vaccination, while 16% received low-quality recommendations and 36% received high-quality recommendations. Compared to no recommendation, high-quality recommendations were associated with over nine times the odds of HPV vaccine initiation (23% vs. 74%, OR = 9.31, 95% CI, 7.10–12.22) and over three times the odds of follow through (17% vs. 44%, OR = 3.82, 95% CI, 2.39–6.11). Low-quality recommendations were more modestly associated with initiation (OR = 4.13, 95% CI, 2.99–5.70), but not follow through. Parents who received high- versus low-quality recommendations less often reported HPV vaccine refusal or delay.ConclusionsHigh-quality recommendations were strongly associated with HPV vaccination behavior, but only about one-third of parents received them. Interventions are needed to improve not only whether, but how providers recommend HPV vaccination for adolescents.     

Barriers to timely administration of birth dose vaccines in The Gambia,West Africa

ObjectiveAlthough vaccine coverage in infants in sub-Saharan Africa is high, this is estimated at the age of 6–12 months. There is little information on the timely administration of birth dose vaccines. The objective of this study was to assess the timing of birth dose vaccines (hepatitis B, BCG and oral polio) and reasons for delayed administration in The Gambia.MethodsWe used vaccination data from the Farafenni Health and Demographic Surveillance System (FHDSS) between 2004 and 2014. Coverage was calculated at birth (0–1 day), day 7, day 28, 6 months and 1 year of age. Logistic regression models were used to identify demographic and socio-economic variables associated with vaccination by day 7 in children born between 2011 and 2014.ResultsMost of the 10,851 children had received the first dose of hepatitis B virus (HBV) vaccine by the age of 6 months (93.1%). Nevertheless, only 1.1% of them were vaccinated at birth, 5.4% by day 7, and 58.4% by day 28. Vaccination by day 7 was associated with living in urban areas (West rural: adjusted OR (AOR) = 6.13, 95%CI: 3.20–11.75, east rural: AOR = 6.72, 95%CI: 3.66–12.33) and maternal education (senior-educations: AOR = 2.43, 95%CI: 1.17–5.06); and inversely associated with distance to vaccination delivery points (≧2 km: AOR = 0.41, 95%CI: 0.24–0.70), and Fula ethnicity (AOR = 0.60, 95%CI: 0.40–0.91).ConclusionVaccine coverage in The Gambia is high but infants are usually vaccinated after the neonatal period. Interventions to ensure the implementation of national vaccination policies are urgently needed.     

Annual influenza vaccination reduces total hospitalization in patients with chronic hepatitis B virus infection: A population-based analysis

BackgroundThis study evaluated hospitalization and mortality in patients with chronic hepatitis B virus infection (HBV (+)) and matched comparison patients after stratifying the patients according to annual influenza vaccination (Vaccine (+)).MethodsData from Taiwan's National Health Insurance program from 2000 to 2009 were used to identify HBV(+)/vaccine(+) (n = 4434), HBV(+)/Vaccine(−) (n = 3646), HBV(−)/Vaccine(+) (n = 8868), and HBV(−)/Vaccine(−) (n = 8868) cohorts. The risk of pneumonia/influenza, respiratory failure, intensive care, hospitalization, and mortality in the four cohorts was evaluated.ResultsThe total hospitalization rate was significantly lower in patients with chronic HBV infection who received an annual influenza vaccination than in chronic HBV-infected patients who did not receive an influenza vaccination (16.29 vs. 24.02 per 100 person-years), contributing to an adjusted hazard ratio (HR) of 0.56 (95% confidence interval (CI) = 0.50–0.62). The HBV(+)/Vaccine(+) cohort also had lower risks than the HBV(+)/Vaccine(−) cohort for pneumonia and influenza (adjusted HR = 0.79, 95% CI = 0.67–0.92), intensive care unit admission (adjusted HR = 0.33, 95% CI = 0.25–0.43), and mortality (adjusted HR = 0.19, 95% CI = 0.15–0.24).ConclusionsOur results suggest that annual influenza vaccination can reduce the risk of hospitalization and mortality in patients with chronic HBV infection.     

Parental perceptions of childhood seasonal influenza vaccination in Singapore: A cross-sectional survey

PurposeSeasonal influenza vaccination is recommended in children aged 6–59 months, but little is known about child vaccination coverage and determinants in Asian settings. We report the results of a survey of knowledge, attitudes, practices, and determinants of child influenza vaccination in Singapore.MethodsIn December 2015-March 2016, we conducted a survey of 332 parents of children aged 6 months to 5 years attending pre-schools. We assessed child influenza vaccine coverage and parental knowledge, attitudes, and practices of child influenza vaccination. We used multivariable regression and structural equation models to identify factors associated with child influenza vaccination.ResultsKnowledge about influenza, perceived benefit of vaccination, and willingness to vaccinate were high. However, only 32% of children had ever received influenza vaccine, and only 15% in the past year. Factors independently associated with child influenza vaccination included: being recommended influenza vaccine by a child’s doctor (prevalence ratio (PR) = 2.47, 95% CI: 1.75–3.48); receiving influenza vaccine information from a private general practitioner (PR = 1.47, 95% CI: 1.05–2.04); regularly receiving pre-travel influenza vaccine (PR = 1.64, 95% CI: 1.19–2.25); higher willingness to vaccinate (PR = 1.58, 95% CI:1.24–2.04 per unit increase in willingness score); and feeling well-informed about influenza vaccine (PR = 1.44, 95% CI: 1.04–1.99). Parents who obtained influenza vaccine information from television were less likely to have vaccinated their child (PR = 0.44, 95% CI: 0.23–0.85). Path analysis indicated that being recommended vaccination by a child's doctor increased willingness to vaccinate and self-efficacy (feeling well-informed about influenza vaccine). Median willingness-to-pay for a dose of influenza vaccine was SGD30 (interquartile range: SGD20-SGD50), and was higher in parents of vaccinated compared with unvaccinated children (SGD45 vs SGD30, p = 0.0012).ConclusionKnowledge and willingness to vaccinate was high in this parent population, but influenza vaccine uptake in children was low. Encouraging medical professionals to recommend vaccination of eligible children is key to improving uptake.     

Connaissance et couverture vaccinale contre l’hépatite virale B (HVB) : étude transversale parmi les étudiants de l’université de Cocody,Côte d’Ivoire

BackgroundTo evaluate knowledge about hepatitis B and vaccination coverage among students at Cocody's University, Ivory Coast.Materials and methodsA cross-sectional study was conducted during the academic year 2005–2006 (2557 students). Parameters were collected by interview using a survey chart. Factors influencing knowledge and vaccination against hepatitis B were analyzed by logistic regression.ResultsThe majority of students (n = 1174, 69.4% [95% CI 68–71]) knew about hepatitis B. Only 17.5% and 26.1% of students respectively were aware of sexual and blood transmission. None of the students were aware of maternal-fetal transmission. Factors associated with knowledge of hepatitis B were enrollment in health sciences (Odds Ratio = 24.19 [95% CI 8.65–76.63]) and having a scholarship (Odds Ratio = 2.34 [95% CI 1.54–3.56]). Vaccination coverage against hepatitis B was low (Odds Ratio = 3.7% [95% CI 3–4]). Factors associated with vaccination were: knowledge of hepatitis B (Odds Ratio = 6.83 [95% CI 4.57–10.27]), enrollment in health sciences (Odds Ratio = 3.59 [95% CI 2.60–4.96]), marriage (Odds Ratio = 2.04 [95% CI 1.13–3.64]) and having a scholarship (Odds Ratio = 1.60 [95% CI 1.09–2.35]).ConclusionKnowledge and vaccination coverage against hepatitis B among students at Cocody's University is low. Students should be given information about hepatitis B and access to free vaccination. Students enrolled in health sciences should be vaccinated before admission because of specific risks of contamination, for themselves and for their patients.     

Effectiveness of different vaccine schedules for heptavalent and 13-valent conjugate vaccines against pneumococcal disease in the Community of Madrid

IntroductionThe heptavalent pneumococcal conjugate vaccine (PCV-7) was added to the childhood routine vaccination program in the Community of Madrid in November of 2006 with 3 + 1 recommended doses and a catch-up for those under 2 years old. In June 2010, PCV-7 was replaced by 13-valent vaccine (PCV-13) with 2 + 1 recommended doses. In July of 2012, the PCV-13 was removed from the funded program and reintroduced again (2 + 1 recommended doses) in December 2014. In between, children were vaccinated privately with 3 + 1 recommended doses of PCV-13. The aim of this study was to evaluate the effectiveness of each vaccination schedule used in the Community of Madrid.MethodsWe included all cases of invasive pneumococcal disease (IPD) reported between 2007 and 2015 to the Notifiable Diseases Surveillance System. Vaccination information was obtained from the Immunization Registry. Vaccine effectiveness (VE) was estimated using the indirect cohort design for cases with serotype information.ResultsA total 779 cases were included in the study. Among them 47.6% of the cases were primo-vaccinated with booster, 20% primo-vaccinated, 15.9% incompletely primo-vaccinated and 16.5% not vaccinated. The VE for ≥1 doses of any PCV was 82% (CI 95%: 67.8–89.9%): 91.9% (CI 95%: 76.5–97.2%) for PCV-7 and 77.2% (48.6–89.9%) for PCV-13. VE in those receiving the full 2 + 1 or 3 + 1 schedules was 100% for both vaccines.ConclusionsA high number of vaccine failures were reported in children before they had the opportunity to receive the booster dose, especially due to PCV-13-non-PCV-7 serotypes. VE was higher for PCV-7 compared to PCV-13, except for those that received the complete schedule with booster that achieved 100% of VE, which shows the relevance of the vaccines and complying with all doses scheduled.     

Prevalence and decay of maternal pneumococcal and meningococcal antibodies: A meta-analysis of type-specific decay rates

BackgroundAt the time of an infant’s initial vaccination at age ∼2 to 3 months, some infants already have maternal antibodies against vaccine antigens and these can suppress the immune response to vaccination. Modelling the effects of maternal antibody and the timing of infant doses on the antibody response to vaccination, requires estimates of the rate of maternal antibody decay. Decay rates are not well characterised in the medical literature. We investigated variation in the prevalence of maternal anti-capsular pneumococcal and meningococcal antibodies in infants in 14 countries, and estimated type-specific half-lives.MethodsIndividual participant serological data were obtained from clinical trials. Half-lives were estimated from antibody concentrations in infants who did not receive meningococcal or pneumococcal vaccines.ResultsThe seroprevalence of maternal pneumococcal antibodies was highest for serotypes 14, and 19F (92% and 80% respectively) and lowest for serotypes 4 and 1 (30% and 34% respectively). Half-life estimates ranged from 38.7 days (95% CI 36.6–41.0) for serotype 6B, to 48.3 days (95% CI 46.7–50.2) for serotype 5. The overall half-life was 42.6 days (95% CI 41.5–43.7). Seroprevalence was highest in Mali, Nigeria, India, and the Philippines, (all >65%) and lowest in the Czech Republic and Finland (both <45%).In studies of meningococcal vaccines, seroprevalence was 13% for group C (half-life 39.8 days, 95% CI 33.4–49.4) and 43% for group A (half-life 43.1 days 95% CI 39.8–47.2).ConclusionSubstantial proportions of infants in many countries have antibodies to vaccine serotypes of pneumococcus, however fewer infants have maternally acquired antibodies to groups A and C meningococcus.Passively-acquired antibodies to capsular polysaccharides decay with a half-life of approximately 6 weeks. These estimates are useful for modelling the impact of proposed vaccination programmes, and consideration of schedules with a delayed start.     

Chronically ill adolescents are also incompletely vaccinated: A cross-sectional study in France

BackgroundAdolescent vaccination coverage tends to be suboptimal, leading to resurgent infectious pathologies and vulnerability to various pathogens. The low frequency of medical consultations and missed opportunities for vaccination are often used to explain the low rate of vaccination. The aim of this study was to assess if the vaccination coverage rate is higher in chronically ill adolescents (CIA) who require a close pediatric specialized follow-up versus the rate in healthy adolescents (HA).MethodsA monocentric cross-sectional study was conducted in the Nantes University Hospital. We included 114 CIA and 266 HA. The vaccination coverage rate and the up-to-date immunization status were compared between ill versus healthy adolescents for each of the following vaccines: diphtheria, tetanus, acellular pertussis, inactivated poliovirus (DTaP/IPV), measles-mumps-rubella (MMR), hepatitis B (HepB), meningococcal C conjugate (MnC), human papillomavirus (HPV) and composite combinations (e.g. DTaP/IPV-MMR-HepB-MnC).ResultsThe overall immunization rate for DTaP/IPV-MMR-HepB-MnC was very low, with no significant difference between CIA and HA (9.6% versus 13.5%; p = 0.28). Most of the investigated vaccines exhibited similar immunization patterns for the two groups: DTaP/IPV (77.2 vs. 76.7%; p = 0.97), MMR (92.1 vs. 95.9%; p = 0.14), HepB (51.8 vs. 48.5%; p = 0.51) with the exception of the MnC (18.4 vs. 27.8%; p = 0.05) and HPV (28.6 vs. 16.1%; p = 0.04).ConclusionDespite undergoing specialized and close medical follow-up, we found that the vaccination coverage rate for the CIA remained suboptimal. This indicates that pediatricians need to check the vaccination status and, when required, ensure that the vaccination schedules for these fragile patients are up-to-date.     

Actions improving HPV vaccination uptake – Results from a national survey in Italy

BackgroundIn Italy, HPV vaccination is offered to 11-year-old girls since 2007. In 2012 coverage was 69%. Strategies for offering and promoting HPV vaccination and coverage rates (26–85%) vary among Regions and Local Health Authorities (LHAs). We conducted a national study to identify strategies to improve HPV vaccination uptake.MethodsIn 2011–2012 we invited the 178 LHAs to fill a web-questionnaire, inquiring implementation of HPV vaccination campaigns (immunization practices, logistics of vaccine delivery, training, activities to promote vaccination, barriers, local context). We described type of offer and vaccination promotion in each LHA and studied the association of these factors with vaccination coverage rates.ResultsWe analyzed 133 questionnaires. The communication tools more frequently used to promote vaccination were: brochures/leaflets (92% of LHAs), fliers/posters (72%). Television (24%) and radio (15%) were less used. Using ≥3 communication channels was associated to a coverage ≥70% (OR_adj = 5.9, 95%CI 2.0–17.4). The probability to reach a coverage ≥70% was higher if the invitation letter indicated a pre-assigned date for HPV vaccination (OR_adj = 7.0, 95%CI 1.2–39.8) and >1 recall for non-respondents was planned (OR_adj = 4.1, 95%CI 1.8–9.3). Immunization services and paediatricians were involved in informative and training activities in most LHAs (80–90%), instead general practitioners, women and family's healthcare services and public gynaecologists in 60–70%, cervical cancer screening services and private gynaecologists in 20–40%. The main factors that negatively affected vaccination uptake were: poor participation to training events of professional profiles different from personnel of immunization services (reported by 58% LHAs), their mistrust towards HPV vaccination (55%) and insufficient resources (56%).ConclusionThe synergy of multiple interventions is necessary for a successful vaccination programme. Practices such as pre-assigning vaccination date and repeatedly recalling non-respondents could improve vaccination uptake. Efforts are required to strengthen the training of different professional profiles and services and encourage their collaboration. Economical resources are needed to promote vaccination.     

Patterns and predictors of state adult obesity prevention legislation enactment in US states: 2010–2013

ObjectiveThis study examined bill- and state-level factors associated with enactment of adult obesity prevention legislation in US states.MethodsA review of bills in the Rudd Center for Food Policy and Obesity's legislative database identified 487 adult obesity prevention bills, or proposed legislation, introduced between 2010 and 2013. Multilevel models were constructed to examine bill- and state-level characteristics associated with enactment.ResultsFrom 2010 to 2013, 81 (17%) of obesity prevention bills introduced were enacted across 35 states and the District of Columbia. Bills introduced in 2010 were more likely to be enacted than in 2013 (OR = 9.49; 95% CI: 2.61–34.5). Bills focused on access to healthy food, physical activity, general and educational programs, as well as modifying rules and procedures (e.g., preemption) had greater odds of enactment relative to food and beverage taxes (OR = 8.18; 95% CI: 2.85–23.4 healthy food; OR = 17.3; 95% CI: 4.55–65.7 physical activity; OR = 15.2; 95% CI: 4.80–47.9 general; OR = 13.7; 95% CI: 3.07–61.5 rules).ConclusionThe year of bill introduction and overall bill enactment rate were related to adult obesity prevention legislation enactment in states. This study highlights the importance of a bill's topic area for enactment and provides insights for advocates and policymakers trying to address enactment barriers.     

Evaluación de una intervención comunitaria para incrementar la cobertura vacunal de la gripe en mujeres embarazadas

ObjectiveTo know the impact of the educational intervention carried out on the professionals of a basic health area and their community participation group, which make up the intervention group (IG), and to analyze its repercussion on the vaccination coverage achieved for influenza in the risk group (pregnant and puerperal women) comparing it with its neighboring basic zone, which makes up the control group (CG), during the 2019/20 vaccination season.DesignQuasi-experimental study of community intervention.SiteTwo basic health zones belonging to the Elche-Crevillente health department, Spain.ParticipantsPregnant and postpartum women from 2 basic health areas and the community participation group. Health professionals directly related to the flu vaccination campaign.InterventionsTraining session for the IG prior to the 2019/20 flu campaign.Main measurementsAttitudes towards influenza vaccination in health professionals through the validated CAPSVA questionnaire and the vaccination coverage of pregnant and postpartum women through the Nominal Vaccine Registry and their acceptance of the vaccine in the midwife's office.ResultsThe influenza vaccination coverage data recorded in Nominal Vaccine Registry for pregnant and puerperal women was 26.4% (n = 207) in the IG and 19.7% (n = 144) in the CG (p = 0.001), with an incidence ratio of 1.34, thus achieving 34% more vaccination in the IG. Acceptance for vaccination in the midwife's office was also high, with 96.5% immunization in IG vs. 89.0% in CG, with a RR = 1.09 (95% CI 1.01-1.62).ConclusionsJoint training strategies for professionals and community assets improve the results of vaccination coverage.     

What predicts postpartum pertussis booster vaccination? A controlled intervention trial

Background‘Cocooning’ aims to protect susceptible infants from pertussis via caregiver vaccination. Control trials evaluating educational interventions to promote cocooning are lacking. We evaluated the role of message-framing vs. standard health information in promoting pertussis vaccination.MethodsWe recruited postpartum women from a maternity hospital in Sydney, Australia (November 2010–July 2012). Participants self-completed a pertussis knowledge and attitudes questionnaire. We then assigned pertussis-susceptible (no pertussis vaccine ≤10 years) participants to receive a gain-framed, loss-framed pamphlet or control (Government Pertussis factsheet) using weekly sequential block allocation. Next, participants were offered a pertussis vaccine (dTpa) and completed a post-questionnaire on discharge.ResultsA baseline questionnaire was completed for 96.4% (1433/1486) of postpartum women approached. Missing data was excluded (n = 29). Next, participants (1404) were screened for vaccine status: 324 (23%) reported prior pertussis booster vaccine receipt, leaving 1080 participants requiring vaccination. Among susceptible mothers, 70% (754/1080) were vaccinated post-intervention. Rates were similar between ‘gain’, ‘loss’ or ‘control’ pamphlets (69.1% vs. 71.8% vs. 68.8%; p = 0.62). Intention to be vaccinated (OR 2.46, p < 0.001; 95% CI: 1.69–3.58), perceived vaccine benefits (OR: 1.61, p < 0.001; 95% CI: 1.25–2.15) and having received a vaccine recommendation (OR 1.68; p = 0.025; 95% CI: 1.07–2.65) were independent predictors of vaccine uptake. At discharge, overall pertussis vaccine coverage had increased from 23% to 77% among women screened (1078/1404).ConclusionA cocooning strategy for pertussis vaccination can be highly effective when partially implemented within maternity hospitals, with information accompanied by a funded vaccine. Mothers were highly receptive to vaccination in the postnatal ward: facts about pertussis were as effective as message-framing in promoting a high uptake of 70%. Perceived vaccine benefits, intentions and vaccine recommendation were important predictors of uptake. Our intervention trial increased the existing pertussis vaccine coverage of 23–77%.     

Influenza during pregnancy: Incidence,vaccination coverage and attitudes toward vaccination in the French web-based cohort G-GrippeNet

IntroductionPregnancy is a risk factor for severe influenza. However, data on influenza incidence during pregnancy are scarce. Likewise, no data are available on influenza vaccine coverage in France since national recommendation in 2012. We aimed to assess these points using a novel nationwide web-based surveillance system, G-GrippeNet.MethodsDuring the 2014/2015 influenza season, pregnant women living in metropolitan France were enrolled through a web platform (https://www.grippenet.fr/). Throughout the season, participants were asked to report, on a weekly basis, if they had experienced symptoms of influenza-like-illness (ILI). ILI episodes reported were used to calculate incidence density rates based on period of participation from each participant. Vaccination coverage was estimated after weighing on age and education level from national data on pregnant women. Factors associated with higher vaccination coverage were obtained through a logistic regression with Odds Ratio (OR) corrected with the Zhang and Yu method.ResultsA total of 153 women were enrolled. ILI incidence density rate was 1.8 per 100 person-week (95%CI, 1.5–2.1). This rate was higher in women older than 40 years (RR = 3.0, 95%CI [1.1–8.3], p = 0.03) and during first/second trimesters compared to third trimester (RR = 4.0, 95%CI [1.4–12.0], p = 0.01). Crude vaccination coverage was 39% (95%CI, 31–47) and weighted vaccination coverage was estimated at 26% (95%CI, 20–34). Health care provider recommendation for vaccination (corrected OR = 7.8; 95%CI [3.0–17.1]) and non-smoking status (cOR = 2.1; 95%CI [1.2–6.9]) were associated with higher vaccine uptake.ConclusionThis original web based longitudinal surveillance study design proved feasible in pregnant women population. First results are of interest and underline that public health policies should emphasize the vaccination promotion through health care providers.     

The free vaccination policy of influenza in Beijing,China: The vaccine coverage and its associated factors

BackgroundIn order to improve influenza vaccination coverage, the coverage rate and reasons for non-vaccination need to be determined. In 2007, the Beijing Government published a policy providing free influenza vaccinations to elderly people living in Beijing who are older than 60. This study examines the vaccination coverage after the policy was carried out and factors influencing vaccination among the elderly in Beijing.MethodsA cross-sectional survey was conducted through the use of questionnaires in 2013. A total of 1673 eligible participants were selected by multistage stratified random sampling in Beijing using anonymous questionnaires in-person. They were surveyed to determine vaccination status and social demographic information.ResultsThe influenza vaccination coverage was 38.7% among elderly people in Beijing in 2012. The most common reason for not being vaccinated was people thinking they did not need to have a flu shot. After controlling for age, gender, income, self-reported health status, and the acceptance of health promotion, the rate in rural areas was 2.566 (95% confidence interval [CI], 1.801–3.655, P < 0.010) times greater than that in urban areas. Different mechanisms of health education and health promotion have different influences on vaccination uptake. Those whom received information through television, community boards, or doctors were more likely to get vaccinated compared to those who did not (Odds Ratio [OR] = 1.403, P < 0.010; OR = 1.812, P < 0.010; OR = 2.647, P < 0.010).ConclusionThe influenza vaccine coverage in Beijing is much lower than that of developed countries with similar policies. The rural–urban disparity in coverage rate (64.1% versus 33.5%), may be explained by differing health provision systems and personal attitudes toward free services due to socioeconomic factors. Methods for increasing vaccination levels include increasing the focus on primary care and health education programs, particularly recommendations from doctors, to the distinct target populations, especially with a focus on expanding these efforts in urban areas.     

Measles seroprevalence in Chiradzulu district,Malawi: Implications for evaluating vaccine coverage

IntroductionSelf-reported measles vaccination coverage is frequently used to inform vaccination strategies in resource-poor settings. However, little is known to what extent this is a reliable indicator of underlying seroprotection, information that could provide guidance ensuring the success of measles control and elimination strategies.MethodsAs part of a study exploring HIV infection and measles susceptibility, we conveniently sampled consenting HIV-uninfected patients presenting at the HIV voluntary counselling and testing centre, and HIV-infected patients presenting for regular care, in Chiradzulu district hospital, Malawi, between January and September 2012.ResultsA total of 2106 participants were recruited between January and September 2012, three quarters of whom were HIV positive. Vaccination cards were available for just 7 participants (0.36%). 91.9% of participants were measles seropositive.Older age (OR = 1.11 per year increase in age; 95%CI: 1.09–1.14) and being female (OR = 1.90; 95%CI: 1.26–2.87) were both associated with significantly increased odds for seroprotection. Prior vaccination history was associated with lower odds (Odds Ratio (OR) = 0.44; 95% confidence interval (CI): 0.22–0.85) for confirmed seropositivity. Previous measles infection was not significantly associated with seroprotection (OR = 1.31; 95%CI: 0.49–3.51).Protection by history and serological status were concordant for 64.3% of participants <35 years old. However, analysis by age group reveals important differences in concordance between the ages, with a greater degree of discordance among younger ages.Vaccination and/or infection history as a predictor of seropositivity was 75.8% sensitive, but just 10.3% specific.ConclusionReported vaccination and previous infection were poor predictors of seropositivity, suggesting these may be unreliable indicators of seroprotection status. Such serosurveys may be indicated in similar settings in which overestimation of the proportion of seroprotected individuals could have important ramifications if used to guide vaccination strategies.     

Childhood vaccines and Kawasaki disease,Vaccine Safety Datalink, 1996-2006

BackgroundKawasaki disease is a childhood vascular disorder of unknown etiology. Concerns have been raised about vaccinations being a potential risk factor for Kawasaki disease.MethodsData from the Vaccine Safety Datalink were collected on children aged 0–6 years at seven managed care organizations across the United States. Defining exposure as one of several time periods up to 42 days after vaccination, we conducted Poisson regressions controlling for age, sex, season, and managed care organization to determine if rates of physician-diagnosed and verified Kawasaki disease were elevated following vaccination compared to rates during all unexposed periods. We also performed case-crossover analyses to control for unmeasured confounding.ResultsA total of 1,721,186 children aged 0–6 years from seven managed care organizations were followed for a combined 4,417,766 person-years. The rate of verified Kawasaki disease was significantly lower during the 1–42 days after vaccination (rate ratio = 0.50, 95% CL = 0.27–0.92) and 8–42 days after vaccination (rate ratio = 0.45, 95% CL = 0.22–0.90) compared to rates during unexposed periods. Breaking down the analysis by vaccination category did not identify a subset of vaccines which was solely responsible for this association. The case-crossover analyses revealed that children with Kawasaki disease had lower rates of vaccination in the 42 days prior to symptom onset for both physician-diagnosed Kawasaki disease (rate ratio = 0.79, 95% CL = 0.64–0.97) and verified Kawasaki disease (rate ratio = 0.38, 95% CL = 0.20–0.75).ConclusionsChildhood vaccinations’ studied did not increase the risk of Kawasaki disease; conversely, vaccination was associated with a transient decrease in Kawasaki disease incidence. Verifying and understanding this potential protective effect could yield clues to the underlying etiology of Kawasaki disease.     

Control selection and confounding factors: A lesson from a Japanese case-control study to examine acellular pertussis vaccine effectiveness

When using a case-control study design to examine vaccine effectiveness, both the selection of control subjects and the consideration of potential confounders must be the important issues to ensure accurate results. In this report, we described our experience from a case-control study conducted to evaluate the effectiveness of acellular pertussis vaccine combined with diphtheria-tetanus toxoids (DTaP vaccine). Newly diagnosed pertussis cases and age- and sex-matched friend-controls were enrolled, and the history of DTaP vaccination was compared between groups. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of vaccination for development of pertussis.After adjustment for potential confounders, four doses of DTaP vaccination showed a lower OR for pediatrician-diagnosed pertussis (OR = 0.11, 95% CI, 0.01–0.99). In addition, the decreasing OR of four doses vaccination was more pronounced for laboratory-confirmed pertussis (OR = 0.07, 95%CI, 0.01–0.82). Besides, positive association with pertussis was observed in subjects with a history of steroid treatment (OR = 5.67) and those with a recent contact with a lasting cough (OR = 4.12).When using a case-control study to evaluate the effectiveness of vaccines, particularly those for uncommon infectious diseases such as pertussis, the use of friend-controls may be optimal due to the fact that they shared a similar experience for exposure to the pathogen as the cases. In addition, to assess vaccine effectiveness as accurately as possible, the effects of confounding should be adequately controlled with a matching or analysis technique.     

Effectiveness of acellular pertussis vaccine in a routine immunization program: A multicenter,case-control study in Japan

In 2008, the number of pertussis cases increased substantially among Japanese adolescents, despite high coverage with acellular pertussis vaccine (DTaP). This study examined the effectiveness of DTaP vaccine in the routine immunization program in Japan. Between April 2009 and October 2012, we conducted a multicenter, case-control study, and compared the history of DTaP vaccination between 55 newly diagnosed pertussis cases and 90 age- and sex-matched controls. DTaP vaccine history was obtained by a self-administered questionnaire completed by their parents or guardians. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of vaccination for development of pertussis.DTaP vaccination of ≥1 dose revealed a significantly lower OR for pertussis (OR = 0.20, 95%CI, 0.04–0.97), and the OR of complete vaccination (4 doses) was 0.22 (0.04–1.05). Even after limiting subjects to those whose vaccination status could be confirmed by the immunization records, the negative associations were observed. The decreasing ORs of 4-dose vaccinees remained, even among subjects who had received the fourth dose ≥9.2 years earlier (OR = 0.11, 95%CI, 0.01–1.02).In conclusion, DTaP vaccination had a preventive effect for pertussis. Effectiveness was observed even 9 or more years after the final dose.