Vaccine effectiveness against COVID-19 hospitalisation in adults (≥ 20 years) during Omicron-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021 to 2022.

IntroductionThe I-MOVE-COVID-19 and VEBIS hospital networks have been measuring COVID-19 vaccine effectiveness (VE) in participating European countries since early 2021.AimWe aimed to measure VE against PCR-confirmed SARS-CoV-2 in patients ≥ 20 years hospitalised with severe acute respiratory infection (SARI) from December 2021 to July 2022 (Omicron-dominant period).MethodsIn both networks, 46 hospitals (13 countries) follow a similar test-negative case-control protocol. We defined complete primary series vaccination (PSV) and first booster dose vaccination as last dose of either vaccine received ≥ 14 days before symptom onset (stratifying first booster into received < 150 and ≥ 150 days after last PSV dose). We measured VE overall, by vaccine category/product, age group and time since first mRNA booster dose, adjusting by site as a fixed effect, and by swab date, age, sex, and presence/absence of at least one commonly collected chronic condition.ResultsWe included 2,779 cases and 2,362 controls. The VE of all vaccine products combined against hospitalisation for laboratory-confirmed SARS-CoV-2 was 43% (95% CI: 29-54) for complete PSV (with last dose received ≥ 150 days before onset), while it was 59% (95% CI: 51-66) after addition of one booster dose. The VE was 85% (95% CI: 78-89), 70% (95% CI: 61-77) and 36% (95% CI: 17-51) for those with onset 14-59 days, 60-119 days and 120-179 days after booster vaccination, respectively.ConclusionsOur results suggest that, during the Omicron period, observed VE against SARI hospitalisation improved with first mRNA booster dose, particularly for those having symptom onset < 120 days after first booster dose.

Influenza vaccine effectiveness in patients hospitalized with severe acute respiratory infection in Lithuania during the 2019-2020 influenza season: a test negative case - control study.

BACKGROUND: Influenza is a contagious viral airborne disease that adds to the clinical and economic burden on the healthcare system. It could be prevented substantially by seasonal influenza vaccination. Seasonal influenza vaccine effectiveness (SIVE) varies a lot and should therefore be monitored. This report aims to update age-stratified SIVE estimates among patients hospitalized due to severe acute respiratory infection (SARI) during the 2019-2020 influenza season. METHODS: We performed a test-negative case-control study between December 2019 and April 2020 influenza season. We estimated SIVE and its 95% confidence intervals (95% CI) with logistic regression as (1-odds ratio)*100%. The models were adjusted for covariates that changed the unadjusted SIVE by ≥ 10%. RESULTS: Among 84 participants, 32 (38.1%) were influenza positive, mostly with A(H1N1)pdm09 (25 cases; 78.1%). SIVE against any influenza adjusted for age and heart disease was 39.2% (95% CI: -119.3%, 83.1%). Age-stratified point estimates adjusted for heart diseases indicated different SIVE, and were 64.0% (95% CI: -309.2%, 96.8%) and 21.6% (95% CI: -252.2%, 82.6%) for 18-64 and ≥ 65 year-old participants, respectively. CONCLUSIONS: The point estimates suggested low to moderate SIVE against any influenza among hospitalized 18-64-year-old SARI participants, while low estimates were found in the ≥ 65-year-old group. Although broad SIVE confidence intervals indicate a small sample size and therefore the results can serve only as indicatory, they are in line with the estimates reported by other studies during the 2019-2020 season.

The Egress Enabler: Development and psychometric evaluation of an instrument to measure egressibility.

BACKGROUND: Egressibility has been defined as a person-environment fit issue and describes accessibility to means of evacuation. Although egressibility concerns everyone, it has become a useful concept particularly in relation to safety and accessibility for people with functional limitations, commonly highlighted as a vulnerable group in egress scenarios. Egressibility is an important safety factor, but there has been limited efforts trying to quantify it. OBJECTIVE: The aim has been to develop an instrument to measure egressibility in public buildings, as well as conducting initial psychometric testing of the instrument. METHODS: The Egress Enabler is based on the previously developed Housing Enabler instrument. The Egress Enabler was developed in several steps by an interdisciplinary team, incorporating an expert panel and a case study. RESULTS: Evaluation of content validity was in line with previous similar efforts, inter-rater reliability was considered "good" to "excellent" by means of intraclass correlation, and qualitative assessment of construct validity showed theoretically sound results. CONCLUSIONS: It is suggested that an instrument like the Egress Enabler is needed for a systematic evaluation of egressibility during design. construction or operation. This is needed for ensuring equal access to egress for people with functional limitations.

Exploring Associations of Housing, Relocation, and Active and Healthy Aging in Sweden: Protocol for a Prospective Longitudinal Mixed Methods Study.

BACKGROUND: While housing and neighborhood features have the potential to impact opportunities for active aging, there is a lack of knowledge related to how older people reason regarding their housing situation and how housing and fulfillment of relocation are associated with active and healthy aging. OBJECTIVE: The objectives of Prospective RELOC-AGE are to study housing choices and relocation and explore effects on active and healthy aging among men and women aged 55 years and older in Sweden considering relocation. METHODS: The estimated sample (2800) will include people aged 55 years and older being listed for relocation at either of two housing companies: a local public housing company in Southern Sweden and a national condominium provider. Prospective RELOC-AGE has a 2-level longitudinal mixed methods design and includes quantitative surveys (implemented by a professional survey company) and a telephone interview for baseline data collection in 2021, with follow-ups with the same procedures in 2022 and 2023. The survey and interviews include questions related to present housing and neighborhood, relocation plans and expectations, a range of perspectives on active and healthy aging, and demographics. Linking to national registers will provide additional data on home help and health care use, objective housing, and neighborhood characteristics. To explore what housing attributes older adults considering relocation find important and to what extent when making their decisions on housing, we will develop a discrete choice experiment to be implemented with a subsample of participants. Further, a grounded theory approach will be applied to collect in-depth interview data from participants who have moved to another dwelling, within 6 months of the move. A follow-up interview 12 months later will focus on participants' deepened experience over time in terms of fulfilled expectations and relocation experiences. RESULTS: As of submission of this protocol (June 2021), recruitment has commenced with approximately 960 respondents to the survey and ongoing telephone interviews. We anticipate recruitment and data collection based on surveys and interviews to continue during 2021. CONCLUSIONS: Prospective RELOC-AGE has the capacity to generate new policy-relevant knowledge on associations of housing, relocation, and active and healthy aging. Such knowledge is relevant for the development of proactive approaches to housing in old age on the individual, group, and societal levels. TRIAL REGISTRATION: ClinicalTrials.gov NCT04765696; https://clinicaltrials.gov/ct2/show/NCT04765696. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/31137.

Age-Specific Seasonal Influenza Vaccine Effectiveness against Different Influenza Subtypes in the Hospitalized Population in Lithuania during the 2015-2019 Influenza Seasons.

BACKGROUND: Continuous monitoring of seasonal influenza vaccine effectiveness (SIVE) is needed due to the changing nature of influenza viruses and it supports the decision on the annual update of vaccine composition. Age-specific SIVE was evaluated against different influenza subtypes in the hospitalized population in Lithuania during four influenza seasons. METHODS: A test-negative case-control study design was used. SIVE and its 95% confidence intervals (95% CI) were calculated as (1 - odds ratio (OR)) × 100%. RESULTS: Adjusted SIVE in 18-64-year-old individuals against influenza A, A(H1N1)pdm09 and B/Yamagata were 78.0% (95% CI: 1.7; 95.1%), 88.6% (95% CI: -47.4; 99.1%), and 76.8% (95% CI: -109.9; 97.4%), respectively. Adjusted SIVE in individuals aged 65 years and older against influenza A, influenza B, and B/Yamagata were 22.6% (95% CI: -36.5; 56.1%), 75.3% (95% CI: 12.2; 93.1%) and 73.1% (95% CI: 3.2; 92.5%), respectively. Unadjusted SIVE against influenza A(H3N2) among 18-64-year-old patients was 44.8% (95% CI: -171.0; 88.8%) and among those aged 65 years and older was 5.0% (95% CI: -74.5; 48.3%). CONCLUSIONS: Point estimates suggest high SIVE against influenza A in 18-64-year-old participants, and against influenza B and B/Yamagata in those 65 years old and older.

Longitudinal association between housing accessibility and activities of daily living: the role of self-efficacy and control in people ageing with Parkinson's disease.

BACKGROUND: External housing-related control beliefs (HCB) and general self-efficacy (GSE) influence different health outcomes in the general ageing population, but there is no information of their role in people ageing with Parkinson's disease (PD). This study aimed to longitudinally assess the role of external HCB and GSE on the association between housing accessibility and activities of daily living (ADL) among people ageing with PD. METHODS: Baseline and 3-year follow-up data on 130 community-living participants from the Swedish project 'Home and Health in People Ageing with PD' were collected. Assessments addressed housing accessibility, external HCB, GSE, generic ADL and ADL specific to PD. The moderating effects of external HCB and GSE were assessed by including an interaction term in multivariable logistic regression. RESULTS: There were statistically significant interactions between housing accessibility and GSE on ADL (p = 0.03), and housing accessibility and external HCB on PD specific ADL (p = 0.03). After stratifying the analyses by GSE, housing accessibility problems led to more dependence and difficulty in ADL in participants with low GSE (OR 1.14; 95% CI 1.02-1.28). After stratifying by external HCB, housing accessibility increased dependence and difficulty in PD specific ADL in participants with low external HCB (OR 1.35; 95% CI 1.03-1.76). DISCUSSION: The results suggest that housing accessibility predicts ADL in people with PD with GSE and external HCB playing a moderating role for generic ADL and ADL specific to PD, respectively. Further longitudinal studies should validate these findings and explore their potential application in PD-related care and rehabilitation.

Estimating burden of influenza-associated influenza-like illness and severe acute respiratory infection at public healthcare facilities in Romania during the 2011/12-2015/16 influenza seasons.

BACKGROUND: Influenza is responsible for substantial morbidity and mortality, but there is limited information on reliable disease burden estimates, especially from middle-income countries in the WHO European Region. OBJECTIVES: To estimate the incidence of medically attended influenza-associated influenza-like illness (ILI) and hospitalizations due to severe acute respiratory infection (SARI) presenting to public healthcare facilities in Romania. PATIENTS/METHODS: Sentinel influenza surveillance data for ILI and SARI from 2011/12-2015/16, including virological data, were used to estimate influenza-associated ILI and SARI incidence/100 000 and their 95% confidence intervals (95% CI). RESULTS: The overall annual incidence of ILI and influenza-associated ILI per 100 000 persons in Romania varied between 68 (95% CI: 61-76) and 318 (95% CI: 298-338) and between 23 (95% CI: 19-29) and 189 (95% CI: 149-240), respectively. The highest ILI and influenza incidence was among children aged 0-4 years. We estimated that SARI incidence per 100 000 persons was 6 (95% CI: 5-7) to 9 (95% CI: 8-10), of which 2 (95% CI: 1-2) to 3 (95% CI: 2-4) were due to influenza. Up to 0.3% of the Romanian population were annually reported with ILI, and 0.01% was hospitalized with SARI, of which as much as one-third could be explained by influenza. CONCLUSIONS: This evaluation was the first study estimating influenza burden in Romania. We found that during each influenza season, a substantial number of persons in Romania suffer from influenza-related ILI or are hospitalized due to influenza-associated SARI.

Seasonal influenza vaccine effectiveness against laboratory-confirmed influenza in 2015-2016: a hospital-based test-negative case-control study in Lithuania.

OBJECTIVE: A case-control study was conducted to assess seasonal influenza vaccine effectiveness (SIVE) during the 2015-2016 influenza season. METHODS: A study was performed in three departments in Lithuania between 1 December 2015 and 1 May 2016. Data on demographic and clinical characteristics including influenza vaccination status were collected from the patients recommended to receive the seasonal influenza vaccine. Influenza virus infection was confirmed by multiplex reverse transcription polymerase chain reaction (RT-PCR) . RESULTS: Ninety-one (56.4%) of the 163 included subjects were ≥65 years old. Fifteen (9.2%) subjects were vaccinated against influenza at least 2 weeks before the onset of influenza symptoms, 12 of them were ≥65 years old. Of the 72 (44.2%) influenza virus positive cases, 65 (39.9%) were confirmed with influenza A (including 50 cases of influenza A(H1N1)pdm09), eight (4.9%) were confirmed with influenza B and one was a co-infection. Unadjusted SIVE against any influenza, influenza type A and influenza A(H1N1)pdm09 was 57% (95% CI -41% to 87%), 52% (95% CI -57% to 85%) and 70% (95% CI -43% to 94%) respectively. CONCLUSION: Although SIVE estimates were not statistically significant the point estimates suggest moderate effectiveness against influenza type A.

2015/16 seasonal vaccine effectiveness against hospitalisation with influenza A(H1N1)pdm09 and B among elderly people in Europe: results from the I-MOVE+ project.

We conducted a multicentre test-negative case-control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged ≥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases.

Repeated seasonal influenza vaccination among elderly in Europe: Effects on laboratory confirmed hospitalised influenza.

In Europe, annual influenza vaccination is recommended to elderly. From 2011 to 2014 and in 2015-16, we conducted a multicentre test negative case control study in hospitals of 11 European countries to measure influenza vaccine effectiveness (IVE) against laboratory confirmed hospitalised influenza among people aged ≥65years. We pooled four seasons data to measure IVE by past exposures to influenza vaccination. We swabbed patients admitted for clinical conditions related to influenza with onset of severe acute respiratory infection ≤7days before admission. Cases were patients RT-PCR positive for influenza virus and controls those negative for any influenza virus. We documented seasonal vaccination status for the current season and the two previous seasons. We recruited 5295 patients over the four seasons, including 465A(H1N1)pdm09, 642A(H3N2), 278 B case-patients and 3910 controls. Among patients unvaccinated in both previous two seasons, current seasonal IVE (pooled across seasons) was 30% (95%CI: -35 to 64), 8% (95%CI: -94 to 56) and 33% (95%CI: -43 to 68) against influenza A(H1N1)pdm09, A(H3N2) and B respectively. Among patients vaccinated in both previous seasons, current seasonal IVE (pooled across seasons) was -1% (95%CI: -80 to 43), 37% (95%CI: 7-57) and 43% (95%CI: 1-68) against influenza A(H1N1)pdm09, A(H3N2) and B respectively. Our results suggest that, regardless of patients' recent vaccination history, current seasonal vaccine conferred some protection to vaccinated patients against hospitalisation with influenza A(H3N2) and B. Vaccination of patients already vaccinated in both the past two seasons did not seem to be effective against A(H1N1)pdm09. To better understand the effect of repeated vaccination, engaging in large cohort studies documenting exposures to vaccine and natural infection is needed.

Effectiveness of seasonal influenza vaccination in community-dwelling elderly people: an individual participant data meta-analysis of test-negative design case-control studies.

BACKGROUND: Several aggregate data meta-analyses have provided estimates of the effectiveness of influenza vaccination in community-dwelling elderly people. However, these studies ignored the effects of patient-level confounders such as sex, age, and chronic diseases that could bias effectiveness estimates. We aimed to assess the confounder-adjusted effectiveness of influenza vaccines on laboratory-confirmed influenza among elderly people by conducting a global individual participant data meta-analysis. METHODS: In this individual participant data meta-analysis, we considered studies included in a previously conducted aggregate data meta-analysis that included test-negative design case-control studies published up to July 13, 2014. We contacted all authors of the included studies on Dec 1, 2014, to request individual participant data. Patients were excluded if their unique identifier was missing, their vaccination status was unknown, their outcome status was unknown, or they had had suspected influenza infection more than once in the same influenza season. Cases were patients with influenza-like illness symptoms who tested positive for at least one of A H1N1, A H1N1 pdm09, A H3N2, or B viruses; controls were patients with influenza-like illness symptoms who tested negative for these virus types or subtypes. Influenza vaccine effectiveness against overall and subtype-specific laboratory-confirmed influenza were the primary and secondary outcomes. We used a generalised linear mixed model to calculate adjusted vaccine effectiveness according to vaccine match to the circulating strains of influenza virus and intensity of the virus activity (epidemic or non-epidemic). Vaccine effectiveness was defined as the relative reduction in risk of laboratory-confirmed influenza in vaccinated patients compared with unvaccinated patients. We did subgroup analyses to estimate vaccine effectiveness according to hemisphere, age category, and health status. FINDINGS: We received 23 of the 53 datasets included in the aggregate data meta-analysis. Furthermore, six additional datasets were provided by data collaborators, which resulted in individual participant data for a total of 5210 participants. A total of 4975 patients had the required data for analysis. Of these, 3146 (63%) were controls and 1829 (37%) were cases. Influenza vaccination was significantly effective during epidemic seasons irrespective of vaccine match status (matched adjusted vaccine effectiveness 44·38%, 95% CI 22·63-60·01; mismatched adjusted vaccine effectiveness 20·00%, 95% CI 3·46-33·68; analyses in the imputed dataset). Seasonal influenza vaccination did not show significant effectiveness during non-epidemic seasons. We found substantial variation in vaccine effectiveness across virus types and subtypes, with the highest estimate for A H1N1 pdm09 (53·19%, 10·25-75·58) and the lowest estimate for B virus types (-1·52%, -39·58 to 26·16). Although we observed no significant differences between subgroups in each category (hemisphere, age, and health status), influenza vaccination showed a protective effect among elderly people with cardiovascular disease, lung disease, or aged 75 years and younger. INTERPRETATION: Influenza vaccination is moderately effective against laboratory-confirmed influenza in elderly people during epidemic seasons. More research is needed to investigate factors affecting vaccine protection (eg, brand-specific or type-specific vaccine effectiveness and repeated annual vaccination) in elderly people. FUNDING: University Medical Center Groningen.

After adjusting for bias in meta-analysis seasonal influenza vaccine remains effective in community-dwelling elderly.

OBJECTIVE: To compare the performance of the bias-adjusted meta-analysis to the conventional meta-analysis assessing seasonal influenza vaccine effectiveness among community-dwelling elderly aged 60 years and older. STUDY DESIGN AND SETTING: Systematic literature search revealed 14 cohort studies that met inclusion and exclusion criteria. Laboratory-confirmed influenza, influenza-like illness, hospitalization from influenza and/or pneumonia, and all-cause mortality were study outcomes. Potential biases were identified using bias checklists. The magnitude and uncertainty of biases were assessed by expert opinion. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using random effects model. RESULTS: After incorporating biases, overall effect estimates regressed slightly toward no effect, with the largest relative difference between conventional and bias-adjusted ORs for laboratory-confirmed influenza (OR, 0.18; 95% CI: 0.01, 3.00 vs. OR, 0.23; 95% CI: 0.03, 2.04). In most of the studies, CIs widened reflecting uncertainties about the biases. The between-study heterogeneity reduced considerably with the largest reduction for all-cause mortality (I(2) = 4%, P = 0.39 vs. I(2) = 91%, P < 0.01). CONCLUSION: This case study showed that after addressing potential biases influenza vaccine was still estimated effective in preventing hospitalization from influenza and/or pneumonia and all-cause mortality. Increasing the number of assessors and incorporating empirical evidence might improve the new bias-adjustment method.

Seasonal influenza vaccine effectiveness against influenza in 2012-2013: a hospital-based case-control study in Lithuania.

BACKGROUND: Due to scarce information on seasonal influenza vaccine effectiveness (SIVE) against severe clinical influenza outcomes in risk populations, we conducted a case-control study to assess its effects against laboratory-confirmed influenza in hospitalized patients during the 2012-2013 influenza season. METHODS: We conducted a test-negative case-control study among ≥18 years old patients with influenza-like illness (ILI) hospitalized in two Lithuanian hospitals. Cases were influenza A(H1N1), A(H3) or influenza B positive by RT-PCR, and controls were influenza negative. Additional demographic and clinical data to assess the role of confounding were collected. SIVE and its confidence intervals (95% CI) were estimated by using multivariate logistic regression as (1-OR)×100%. RESULTS: The sample consisted of 185 subjects. Seasonal influenza vaccine uptake was 5%. Among 111 (60%) influenza positive cases, 24.3% were A(H1N1), 10.8% were A(H3) and 24.3% were influenza B cases. Unadjusted SIVE was 79% (95% CI -6% to 96%) and after the adjustment it increased to 86% (95% CI 19% to 97%). CONCLUSIONS: Seasonal influenza vaccination in 2012-2013 was associated with reduced occurrence of laboratory-confirmed influenza, but due to low sample size the estimate of SIVE is imprecise. Given high prevalence of influenza in hospitalized ILI cases and low influenza vaccination coverage, there is a need to increase influenza vaccination rates.

Effectiveness of A(H1N1)pdm09 influenza vaccine in adults recommended for annual influenza vaccination.

INTRODUCTION: Because of variability in published A(H1N1)pdm09 influenza vaccine effectiveness estimates, we conducted a study in the adults belonging to the risk groups to assess the A(H1N1)pdm09 MF59-adjuvanted influenza vaccine effectiveness. METHODS: VE against influenza and/or pneumonia was assessed in the cohort study (n>25000), and vaccine effectiveness against laboratory-confirmed A(H1N1)pdm09 influenza was assessed in a matched case-control study (16 pairs). Odds ratios (OR) and their 95% confidence intervals (95% CI) were calculated by using multivariate logistic regression; vaccine effectiveness was estimated as (1-odds ratio)*100%. RESULTS: Vaccine effectiveness against laboratory-confirmed A(H1N1)pdm09 influenza and influenza and/or pneumonia was 98% (84-100%) and 33% (2-54%) respectively. The vaccine did not prevent influenza and/or pneumonia in 18-59 years old subjects, and was 49% (16-69%) effective in 60 years and older subjects. CONCLUSIONS: Even though we cannot entirely rule out that selection bias, residual confounding and/or cross-protection has played a role, the present results indicate that the MF59-adjuvanted A(H1N1)pdm09 influenza vaccine has been effective in preventing laboratory-confirmed A(H1N1)pdm09 influenza and influenza and/or pneumonia, the latter notably in 60 years and older subjects.

Comparatively low attendance during Human Papillomavirus catch-up vaccination among teenage girls in the Netherlands: Insights from a behavioral survey among parents.

BACKGROUND: The Dutch Human Papillomavirus (HPV) catch-up vaccination program in 2009 appeared less successful than expected. We aimed to identify the most important determinants of refusing the vaccination. METHODS: Two thousand parents of girls born in 1996 targeted for HPV vaccination received an invitation letter to participate in a questionnaire study. Two study groups were defined: the first group consisted of parents of girls who had accepted the vaccine and already received the first dose of HPV vaccination. The second group consisted of parents whose daughters were not vaccinated. The questionnaire consisted of a broad spectrum of possible determinants that were revealed after literature search and discussions with the stakeholders. RESULTS: Four hundred sixty nine questionnaires (24%) were returned, 307 (31%) from those who accepted and 162 (16%) from those who declined the vaccine. The decision not to accept the vaccine was largely determined by: (i) perception that the information provided by the government about the vaccine was limited or biased (OR 13.27); (ii) limited trust, that the government would stop the vaccination program if there were serious side effects (OR 9.95); (iii) lack of knowledge about the effectiveness of the vaccine (OR 7.67); (iv) concerns about the side effects of the vaccine (OR 4.94); (v) lack of conviction that HPV can be extremely harmful (OR 3.78); (vi) perception that the government is strongly influenced by vaccine producers (OR 3.54); and (vii) religious convictions (OR 2.18). CONCLUSIONS: This study revealed several determinants for HPV vaccination uptake after implementation of the HPV vaccine for adolescent girls. These determinants should be taken into consideration in order to successfully implement HPV vaccination into National Immunization Programs.

Predictors of seasonal influenza vaccination among healthcare workers in hospitals: a descriptive meta-analysis.

OBJECTIVE: Vaccinating healthcare workers (HCWs) against influenza is one of the most important methods of decreasing influenza transmission among at-risk patients in healthcare facilities. However, despite recommendations, the rate of uptake of influenza vaccine among HCWs remains low. The objective of this meta-analysis was to determine the most important predictors of seasonal influenza vaccine acceptance among HCWs in hospitals. METHOD: A literature search of PubMed and Embase resulted in 4586 hits. Screening of the titles, abstracts and full text identified 13 studies eligible for inclusion in the meta-analysis. Based on the crude data, pooled risk ratios (Mantel-Haenszel risk ratios, mhRR) and their 95% CIs were calculated using Mantel-Haenszel analysis to estimate the associations of predictors with influenza vaccination status. RESULTS AND CONCLUSION: Knowing that the vaccine is effective (mhRR 2.22; 95% CI 1.93 to 2.54), being willing to prevent influenza transmission (mhRR 2.31; 95% CI 1.97 to 2.70), believing that influenza is highly contagious (RR 2.25; 95% CI 1.66 to 3.05), believing that influenza prevention is important (mhRR 3.63; 95% CI 2.87 to 4.59) and having a family that is usually vaccinated (RR 2.32; 95% CI 1.64 to 3.28) were statistically significantly associated with a twofold higher vaccine uptake. We therefore recommend targeting these predictors when developing new influenza vaccination implementation strategies for hospital HCWs.