Atopic dermatitis incidence and risk factors in young adults in Castellon (Spain): A prospective cohort study.

INTRODUCTION: There are few atopic dermatitis (AD) incidence cohort studies in young adults, the etiology of this disease remains obscure, and AD risk factors in adults are not well understood. The objective of this study was to estimate AD ten-year incidence and prevalence in a cohort of adolescent aged 14-16 at inception in Castellon province in Valencia Region, Spain and describe related risk factors. MATERIAL AND METHODS: From 2002 to 2012, a population-based prospective cohort study was carried out. Questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC) were used with an additional questionnaire for related factors completed by participants and their parents, respectively, in 2002. In 2012 the same questionnaires were completed by the participants' through a telephone interview, and incidence and prevalence of AD were estimated. Directed acyclic graphs, Poisson regression and inverse probability weighted regression adjustment were used. RESULTS: The participation rate was 79.5% (1435/1805) with AD lifetime prevalence of 34.9% and AD incidence of 13.5 per 1000 person years. Females presented higher prevalence and incidence than males. After adjustment significant risk factors were being female, history of asthma or allergic rhinitis, family history of AD, history of respiratory infections, history of bronchitis, history of pneumonia, history of sinusitis, and birthplace outside Castellon province. The highest AD population attributable risks were female, 30.3%, and history of respiratory infections 15.3%. Differences with AD childhood risk factors were found. CONCLUSIONS: AD incidence in our cohort was high and several risks factors were related to AD.

2012/13 influenza vaccine effectiveness against hospitalised influenza A(H1N1)pdm09, A(H3N2) and B: estimates from a European network of hospitals.

While influenza vaccines aim to decrease the incidence of severe influenza among high-risk groups, evidence of influenza vaccine effectiveness (IVE) among the influenza vaccine target population is sparse. We conducted a multicentre test-negative case-control study to estimate IVE against hospitalised laboratory-confirmed influenza in the target population in 18 hospitals in France, Italy, Lithuania and the Navarre and Valencia regions in Spain. All hospitalised patients aged ≥18 years, belonging to the target population presenting with influenza-like illness symptom onset within seven days were swabbed. Patients positive by reverse transcription polymerase chain reaction for influenza virus were cases and those negative were controls. Using logistic regression, we calculated IVE for each influenza virus subtype and adjusted it for month of symptom onset, study site, age and chronic conditions. Of the 1,972 patients included, 116 were positive for influenza A(H1N1)pdm09, 58 for A(H3N2) and 232 for influenza B. Adjusted IVE was 21.3% (95% confidence interval (CI): -25.2 to 50.6; n=1,628), 61.8% (95% CI: 26.8 to 80.0; n=557) and 43.1% (95% CI: 21.2 to 58.9; n=1,526) against influenza A(H1N1) pdm09, A(H3N2) and B respectively. Our results suggest that the 2012/13 IVE was moderate against influenza A(H3N2) and B and low against influenza A(H1N1) pdm09.

Effectiveness of influenza vaccination programme in preventing hospital admissions, Valencia, 2014/15 early results.

Preliminary results for the 2014/15 season indicate low to null effect of vaccination against influenza A(H3N2)-related disease. As of week 5 2015, there have been 1,136 hospital admissions, 210 were due to influenza and 98% of subtype A strains were H3. Adjusted influenza vaccine effectiveness was 33% (range: 6-53%) overall and 40% (range: 13% to 59%) in those 65 years and older. Vaccination reduced by 44% (28-68%) the probability of admission with influenza.

[Efficacy, effectiveness and safety of the adjuvanted influenza vaccine in the population aged 65 or over]. / Eficacia, efectividad y seguridad de la vacuna antigripal adyuvada en población de 65 o más años de edad.

Most of the complications and deaths related to seasonal flu occur in the elderly population (≥65 years) with comorbidities, and the influenza vaccine is the most effective way to prevent them. Immunization is less effective in older adults due to immunosenescence. MF59-adjuvanted vaccines, designed to improve the magnitude, persistence and amplitude of the immune response in elderly people, have been used in clinical practice since 1997 in their trivalent formulation and, since 2020, in their tetravalent formulation. Data from various studies show that these vaccines are not only safe for all age groups, with a reactogenicity profile similar to that of the conventional vaccine, but also that they are especially effective in boosting the immune response in the population aged 65 or over by increasing antibody titers after vaccination and significantly reducing the risk of hospital admission. Adjuvanted vaccines have been shown to provide cross-protection against heterologous strains and to be as effective as the high-dose vaccine in the population aged 65 or over. In this review, the scientific evidence on the efficacy and effectiveness of the MF59-adjuvanted vaccine in real clinical practice in people ≥65 years of age is analyzed through a narrative and descriptive review of the literature with data from clinical trials, observational studies and systematic reviews or meta-analysis.

The PHH-1V HIPRA vaccine: a new tool in the vaccination strategy against COVID-19.

OBJECTIVE: Vaccination against SARS-CoV-2 is essential to mitigate the personal, social and global impact of the coronavirus disease (COVID-19) as we move from a pandemic to an endemic phase. Vaccines are now required that offer broad, long-lasting immunological protection from infection in addition to protection from severe illness and hospitalisation. Here we present a review of the evidence base for a new COVID-19 vaccine, PHH-1V (Bimervax®; HIPRA HUMAN HEALTH S.L.U), and the results of an expert consensus. METHODS: The expert committee consisted of Spanish experts in medicine, family medicine, paediatrics, immunology, microbiology, nursing, and veterinary medicine. Consensus was achieved using a 4-phase process consisting of a face-to-face meeting during which the scientific evidence base was reviewed, an online questionnaire to elicit opinions on the value of PHH-1V, a second face-to-face update meeting to discuss the evolution of the epidemiological situation, vaccine programmes and the scientific evidence for PHH-1V and a final face-to-face meeting at which consensus was achieved. RESULTS: The experts agreed that PHH-1V constitutes a valuable novel vaccine for the development of vaccination programmes aimed towards protecting the population from SARS-CoV-2 infection and disease. Consensus was based on evidence of broad-spectrum efficacy against established and emerging SARS-CoV-2 variants, a potent immunological response, and a good safety profile. The physicochemical properties of the PHH-1V formulation facilitate handling and storage appropriate for global uptake. CONCLUSIONS: The physicochemical properties, formulation, immunogenicity and low reactogenic profile of PHH-1V confirm the appropriateness of this new COVID-19 vaccine.

[Incidence of allergic rhinitis in a cohort of schoolchildren between 1994 and 2002 in Castellón (Spain), following the ISAAC study]. / Incidencia de rinitis alérgica en escolares entre 1994 y 2002 en Castellón según el estudio ISAAC.

OBJECTIVE: To estimate the incidence of allergic rhinitis in schoolchildren in Castellón by comparing phases I and III of the International Study of Asthma and Allergies in Childhood (ISAAC), carried out in 1994 and 2002, respectively. MATERIAL AND METHODS: A cohort study was performed with 3607 schoolchildren aged 6-7 years old who participated in phase I of the ISAAC study. Of these, 1805 participated in phase III (8 years later) at the age of 14-15 years, with 1627 schoolchildren without allergic rhinitis in phase I. The cumulative incidence of allergic rhinitis was estimated. Two definitions of new cases of allergic rhinitis were used: the first was based on medical diagnosis or treatment of the disease, and the second also included symptoms of allergic rhinitis in the previous 12 months. Relative risks were calculated using Poisson regression. RESULTS: Participation was 50.0 %, and 151 new cases of allergic rhinitis according to the first definition (cumulative incidence of 9.3 % and 1.2 % per year) and 339 new cases according to the second definition (cumulative incidence of 20.8 % and 2.6 % per year) were found. No differences in incidence by gender were observed with the first definition (RR = 1.00 95 % CI 0.73-1.38) but with the second definition, the incidence was greater in girls (RR = 1.46 95 % CI 1.18-1.82). CONCLUSIONS: The cumulative incidence of allergic rhinitis according to the first definition was in the range of incidence from cohort studies of adolescents.

Waning protection of influenza vaccination during four influenza seasons, 2011/2012 to 2014/2015.

BACKGROUND: Concerns have been raised about intraseasonal waning of the protection conferred by influenza vaccination. METHODS: During four influenza seasons, we consecutively recruited individuals aged 18years or older who had received seasonal influenza vaccine and were subsequently admitted to the hospital for influenza infection, asassessed by reverse transcription polymerase chain reaction. We estimated the adjusted odds ratio (aOR) of influenza infection by date of vaccination, defined by tertiles, as early, intermediate or late vaccination. We used a test-negative approach with early vaccination as reference to estimate the aOR of hospital admission with influenza among late vaccinees. We conducted sensitivity analyses by means of conditional logistic regression, Cox proportional hazards regression, and using days between vaccination and hospital admission rather than vaccination date. RESULTS: Among 3615 admitted vaccinees, 822 (23%) were positive for influenza. We observed a lower risk of influenza among late vaccinees during the 2011/2012 and 2014/2015A(H3N2)-dominant seasons: aOR=0.68 (95% CI: 0.47-1.00) and 0.69 (95% CI: 0.50-0.95). We found no differences in the risk of admission with influenza among late versus early vaccinees in the 2012/2013A(H1N1)pdm09-dominant or 2013/2014B/Yamagata lineage-dominant seasons: aOR=1.18 (95% CI: 0.58-2.41) and 0.98 (95% CI: 0.56-1.72). When we restricted our analysis to individuals aged 65years or older, we found a statistically significant lower risk of admission with influenza among late vaccinees during the 2011/2012 and 2014/2015A(H3N2)-dominant seasons: aOR=0.61 (95% CI: 0.41-0.91) and 0.69 (95% CI: 0.49-0.96). We observed 39% (95% CI: 9-59%) and 31% (95% CI: 5-50%) waning of vaccine effectiveness among participants aged 65years or older during the two A(H3N2)-dominant seasons. Similar results were obtained in the sensitivity analyses. CONCLUSION: Waning of vaccine protection was observed among individuals aged 65years old or over in two A(H3N2)-dominant influenza seasons.

[Acceptability of human papillomavirus vaccine in mothers from Valencia (Spain)]. / Aceptabilidad de la vacuna contra el virus del papiloma humano en madres de la provincia de Valencia (España).

INTRODUCTION: In October 2008, Valencian Community started its human papillomavirus (HPV) vaccination schedules for 14 year-old girls. The aim of this study is to assess knowledge about HPV infection and its vaccine among the mothers of these girls, and to identify factors associated with the willingness to vaccinate their daughters. MATERIAL AND METHODS: Cross-sectional study by means of a questionnaire to mothers of girls born in 1995, and attending secondary schools in the province of Valencia during 2010-2011. Cluster stratified random sample (n=1279). STATISTICAL ANALYSIS: percentages, confidence intervals, OR, Chi-squared and multivariate logistic regression contrasts. RESULTS: A total of 833 (65.1%) questionnaires were completed. The results obtained showed that, 76.6% of mothers had vaccinated their daughters against HPV; 93.8% knew about the vaccine, particularly through television (71.5%); and 78.5% received positive advice from a health professional which increased the vaccination of their daughters (OR: 2.4). There was low overall knowledge about HPV infection and vaccination. Confidence of the mothers in vaccines as a preventative method increases the HPV vaccination (OR: 3.8). The first reason for refusal was the fear of adverse events (45.6%). CONCLUSIONS: Apparently, the media does not influence the willingness to vaccinate. It would be desirable to minimize the perception of risk of the vaccine. Positive health advice from a health professional can have a positive effect on vaccination. There is a gap between the level of knowledge and decision-making to vaccinate.

Reduction in hospital admissions for pneumonia in non-institutionalised elderly people as a result of influenza vaccination: a case-control study in Spain.

OBJECTIVE: To estimate the effectiveness of influenza vaccine in preventing hospital admission for pneumonia in non-institutionalised elderly people. DESIGN: This was a case-control study. SETTING: All three public hospitals in the Castellón area of Spain. PARTICIPANTS: Cases were people aged 65 or more not living in an institution who were admitted to hospital for pneumonia between November 15, 1994 and March 31, 1995. Each case was matched with two sex matched control subjects aged 65 years or older admitted to hospital in the same week for acute abdominal surgical conditions or trauma. The sampling of incident cases was consecutive. Eighty three cases and 166 controls were identified and included in the study. MEASUREMENTS: Trained interviewers completed a questionnaire for each subject on the vaccination status, smoking habits, previous diseases, health care use, social contacts, family background, the vaccination status of the family carer, home characteristics, and socioeconomic status. RESULTS: The adjusted odds ratio of the influenza vaccination preventing admission to hospital for pneumonia was 0.21 (95% confidence interval 0.09, 0.55). The variables which best explained the risk of being a case were age, intensity of social contacts, health care use, previous diseases, and the existence of a vaccinated family carer. CONCLUSIONS: Influenza vaccination reduced significantly hospital admissions for pneumonia in non-institutionalised elderly people.

[Effectiveness of influenza vaccine in the elderly. A critical review of the bibliography]. / Efectividad de la vacunación antigripal en los ancianos. Una revisión crítica de la bibliografía.

BACKGROUND: The acceptance of influenza vaccine has been slow as doubts about its effectiveness persist. The goal of this study is to review the existing evidence on influenza vaccine effectiveness in preventing pneumonia and influenza hospitalizations in non institutionalized elderly. METHODS: We have conducted a search in MEDLINE, including a period between 1984 and 1994, and of cross references, between 1980 and 1994. Twelve studies have been identified and valued independently by the authors. The results are combined through a graphic representation and the quantitative method proposed by Woolf. RESULTS: Four studies have been excluded; two, because they did not satisfy the comparability principle; one, because it was a publication already published; and one because of small numbers. According to the graphic method, influenza vaccine prevents between 29 and 51 percent of pneumonia and influenza hospitalizations in the non institutionalized elderly. When results are integrated by the quantitative method, the odds ratio is 0.63 (CI 95%, 0.54 to 0.72). The percentage of pneumonia and influenza hospitalizations prevented by the influenza vaccine equals 37.40% (CI 95%, 27.81% to 45.72%) in the vaccinated. CONCLUSIONS: The annual influenza immunization of those 65 years old or older is an effective primary prevention strategy.

[Preventive activities in primary health care: identifying the agreement among evidence-based guidelines]. / Actividades preventivas en atención primaria: identificación de áreas de concordancia entre guías de práctica clínica basadas en la evidencia.

BACKGROUND: The purpose of this article is to identify the agreement among evidence-based guidelines about recommendations on preventive activities in low risk adults. METHODS: For which we identified, from the 1996 US Task Force on Preventive Services Guide those preventives activities classified like A or B (recommendation in favour of provision) and like D or E (recommendation against provision), excepting those D and E recommendations based on descriptives studies or expert opinions. Both preventive activities aimed at pregnant women and children and those which are not applicable to our context were excluded. Selected preventive services were compared with the range of age, sex and periodicity in which agreement with the recommendations of American College of Physicians and Canadian Task Force on Preventive Services existed. RESULTS: We found the following agreements. Screening activities. In favour: screening for hypercholesterolemia, hypertension, breast cancer, colorectal cancer, uterine cervix cancer, rubella, visual and hearing impairment and problem drinking. Against: cancer of prostate, lung, bladder and thyroid, and asymptomatic bacteriuria. Counseling activities. In favour: smoking, motor-vehicles injuries, alcohol consumption, unintended pregnancy. Immunizations and quimioprophylaxis. In favour: Vaccines for influenza, tetanus-diphtheria, hepatitis B and measles-mumps-rubella. Postexposure prophylaxis to hepatitis A, hepatitis B, meningococcal, rabies and tetanus. CONCLUSIONS: We see then, that a high degree in agreement among the main guidelines exists; about the preventive activities to perform in Primary Health Services, nevertheless we observed low fulfillment of certain preventive activities in Primary Health Services, different barriers for the accomplishment from these activities were described.

[Post-licensure passive safety surveillance of rotavirus vaccines: reporting sensitivity for intussusception]. / Vigilancia pasiva de la seguridad postautorización de las vacunas frente a rotavirus: sensibilidad de la notificación de invaginación intestinal.

INTRODUCTION: The aims of this study were to describe the reports of suspected adverse events due to rotavirus vaccines, and assess the reporting sensitivity for intussusception. MATERIAL AND METHODS: Descriptive study performed using the reports of suspected adverse events following rotavirus vaccination in infants aged less than 10 months, as registered in the Pharmacovigilance Centre of the Valencian Community during 2007-2011. The reporting rate for intussusception was compared to the intussusception rate in vaccinated infants obtained using the hospital discharge database (CMBD), and the regional vaccine registry. RESULTS: The adverse event reporting rate was 20 per 100,000 administered doses, with the majority (74%) of the reports being classified as non-serious. Fever, vomiting, and diarrhea were the adverse events reported more frequently. Two intussusception cases, which occurred within the first seven days post-vaccination, were reported as temporarily associated to vaccination. The reporting sensitivity for intussusception at the Pharmacovigilance Centre in the 1-7 day interval following rotavirus vaccination was 50%. CONCLUSIONS: Our results suggest that rotavirus vaccines have, in general, a good safety profile. Intussusception reporting to the Pharmacovigilance Centre shows sensitivity similar to other passive surveillance systems. The intussusception risk should be further investigated using well-designed epidemiological studies, and evaluated in comparison with the well-known benefits provided by these vaccines.

Intradermal and virosomal influenza vaccines for preventing influenza hospitalization in the elderly during the 2011-2012 influenza season: a comparative effectiveness study using the Valencia health care information system.

BACKGROUND: The use of intradermal vaccination or virosomal vaccines could increase protection against influenza among the vulnerable population of older adults. Studies assessing the comparative effectiveness of these two influenza vaccine types in this age group are lacking. METHODS: We conducted a retrospective cohort study to estimate the comparative effectiveness of intradermal seasonal trivalent-influenza vaccine (TIV) delivered by a microneedle injection system and a virosomal-TIV intramuscularly delivered for prevention of influenza hospitalization in non-institutionalized adults aged ≥65 years. We obtained administrative data on immunization status and influenza hospitalization for the 2011-2012 influenza season, and used Cox regression models to assess comparative effectiveness. We estimated crude and adjusted (age, sex, comorbidity, pharmaceutical claims, recent pneumococcal vaccination and number of hospitalizations for all causes other than influenza between the previous and current influenza seasons) hazard ratios (HR). RESULTS: Overall, 164,021 vaccinated subjects were evaluated. There were 127 hospitalizations for influenza among 62,058 subjects, contributing 914,740 person-weeks at risk in the virosomal-TIV group, and 133 hospitalizations for influenza among 101,963 subjects, contributing 1,504,570 person-weeks at risk in the intradermal-TIV group. The crude HR of intradermal-TIV relative to virosomal-TIV was 0.64 (95% confidence interval (CI): 0.50-0.81), and the adjusted Cox estimated HR was 0.67 (95% CI: 0.52-0.85). CONCLUSIONS: During the 2011-2012 influenza season the risk of hospitalization for influenza was reduced by 33% in non-institutionalized elderly adults who were vaccinated with intradermal-TIV compared with virosomal-TIV.

[Suspected adverse events to measles, mumps and rubella vaccine reported to the Community of Valencia Pharmacovigilance Centre]. / Sospecha de reacciones adversas a la vacuna triple vírica notificadas al Centro de Farmacovigilancia de la Comunidad Valenciana.

INTRODUCTION: A Pharmacovigilance system is an important tool for post-marketing monitoring on vaccine safety. Measles, mumps, rubella (MMR) vaccine is a combined vaccine of live attenuated virus. Since its approval, and although the adverse events are considered generally mild, the vaccine has been widely questioned for the controversies arising around its safety. Our objective was to describe suspected adverse events related to MMR vaccine reported to the Valencian Pharmacovigilance Centre. MATERIAL AND METHODS: Descriptive study from cases reported between May 15th, 2005 and May 15th, 2010. After grouping the suspected adverse events by diagnostic criteria, a descriptive analysis of variables was performed. RESULTS: After 545,830 doses administered, 96 notifications were reported (1.76 notifications/100,000 doses) including 181 adverse events. Fever (42.7%) and local inflammation (36.5%) were the most reported events. There were 8.3% notifications classified as severe. Recovery was complete in all cases. CONCLUSIONS: The suspected adverse events reported coincided with those described in the Summary of Product Characteristics of the vaccine. The frequency of reports was lower than previously published estimates. Despite the limitations, the data obtained allowed us to conclude that MMR vaccine has a good safety profile, according to previously published studies.

MF59-adjuvanted and virosomal influenza vaccines for preventing influenza hospitalization in older people: comparative effectiveness using the Valencia health care information system.

BACKGROUND: Adjuvanted influenza vaccines offer greater and broader immunogenicity to older adults than conventional vaccines. Studies assessing the comparative effectiveness of adjuvanted influenza vaccines in this age group are lacking. METHODS: We conducted a retrospective cohort study to estimate the comparative effectiveness of MF59-adjuvanted trivalent influenza vaccine (TIV) and virosomal-TIV for prevention of influenza hospitalization in adults aged ≥65 years. We obtained administrative data on immunization status and influenza hospitalization for the 2010-2011 influenza season. We used Cox regression models to assess comparative effectiveness; crude and adjusted by age, sex, comorbidity, deprivation, type of insurance, and travel time to hospital. We accounted for data clustering at the hospital level by using a multilevel random effects model. RESULTS: Overall, 373,798 vaccinated subjects were evaluated. There were 40 hospitalizations for influenza among 176,618 subjects, contributing 4,288,109 person-weeks at risk in the virosomal-TIV group, and 37 hospitalizations for influenza among 197,180 subjects, contributing 4,786,360 person-weeks at risk in the MF59-TIV group. The crude hazard ratio (HR) was 0.83 (0.53-1.30), and the adjusted Cox estimated HR of MF59-TIV relative to virosomal-TIV was 0.86 (0.55-1.35). After accounting for data clustering, the HR of influenza hospitalization associated with MF59-TIV relative to virosomal-TIV was 0.94 (0.37-2.38). CONCLUSION: During the 2010-2011 influenza season, we found no differences in the risk of influenza hospitalization in subjects aged ≥65 years vaccinated with MF59-TIV compared with those vaccinated with virosomal-TIV.

Safety and immunogenicity of a glycoprotein D genital herpes vaccine in healthy girls 10-17 years of age: results from a randomised, controlled, double-blind trial.

OBJECTIVE: The investigational AS04-adjuvanted herpes simplex virus type 2 (HSV-2) glycoprotein D (gD2) subunit prophylactic vaccine ('HSV vaccine'; GlaxoSmithKline Vaccines) has been shown to be well tolerated in adults, but limited data exist for pre-teen and adolescent girls, a likely target population. The primary objective of this study was to compare the occurrence of serious adverse events (SAEs) over 12 months between HSV vaccine recipients and saline recipients (placebo control group) in pre-teen and adolescent girls. The immunogenicity of the HSV vaccine was also assessed. METHODS: Healthy girls aged 10-17 years, stratified by age (10-15 years; 16-17 years), were randomised 2:1:1 to receive the HSV vaccine, a hepatitis A vaccine (Havrix™; HAV control) or placebo (saline) according to a 0-, 1-, 6-month schedule. Participants and study personnel not involved in the preparation or administration of vaccines were blinded to treatment. Safety and immunogenicity analyses were performed overall and by age (10-15 years; 16-17 years) and HSV serostatus. RESULTS: No statistically significant difference in the percentage of subjects with SAEs was observed between the HSV and saline group, or between the HSV and pooled control (HAV and saline) groups. The HSV vaccine was well tolerated, although a higher incidence of solicited local symptoms was observed in the HSV group than in the control group. Neither age nor HSV serostatus at the time of study entry had an impact on the safety profile of this vaccine. The HSV vaccine was immunogenic regardless of pre-vaccination HSV serostatus. Higher anti-gD geometric mean concentrations were observed in HSV-1 seropositive participants than in HSV-1 seronegative participants. CONCLUSION: The HSV vaccine had an acceptable safety profile, and was well tolerated and immunogenic when administered to girls aged 10-17 years regardless of age or HSV pre-vaccination serostatus.

Effectiveness of the 2010-2011 seasonal influenza vaccine in preventing confirmed influenza hospitalizations in adults: a case-case comparison, case-control study.

INTRODUCTION: We estimated influenza vaccine effectiveness (IVE) to prevent laboratory-confirmed influenza-related hospitalizations in patients 18 years old or older during the 2010-2011 influenza season. METHODS: We conducted a prospective case-control study in five hospitals, in Valencia, Spain. Study subjects were consecutive emergency hospitalizations for predefined conditions associated with an influenza-like illness episode <8 days before admission. Patients were considered immunized if vaccinated ≥14 days before influenza-like illness onset. Cases were those with a real time reverse transcriptase polymerase chain reaction (RT-PCR) positive for influenza and controls were RT-PCR positive for other respiratory viruses. Adjusted IVE was estimated as 100×(1-adjusted odds ratio). To account for indication bias we computed adjusted IVE for respiratory syncytial virus related hospitalizations. RESULTS: Of 826 eligible hospitalized patients, 102 (12%) were influenza positive and considered cases, and 116 (14%) were positive for other respiratory viruses and considered controls. Adjusted IVE was 54% (95% confidence interval, 11-76%). By subgroup, adjusted IVE was 53% (4-77%) for those with high-risk conditions, 59% (16-79%) for those ≥60 years of age, and, 54% (4-79%) for those ≥60 years of age with high-risk conditions. No influenza vaccine effect was observed against respiratory syncytial virus related hospitalization. CONCLUSION: Influenza vaccination was associated with a significant reduction on the risk of confirmed influenza hospitalization, irrespective of age and high-risk conditions.