Survey of distribution of seasonal influenza vaccine doses in 201 countries (2004–2015): The 2003 World Health Assembly resolution on seasonal influenza vaccination coverage and the 2009 influenza pandemic have had very little impact on improving influenza control and pandemic preparedness

There is no global monitoring system for influenza vaccination coverage, making it difficult to assess progress towards the 2003 World Health Assembly (WHA) vaccination coverage target. In 2008, the IFPMA Influenza Vaccine Supply International Task Force (IVS) developed a survey method to assess the global distribution of influenza vaccine doses as a proxy for vaccination coverage rates. The latest dose distribution data for 2014 and 2015 was used to update previous analyses. Data were confidentially collected and aggregated by the IFPMA Secretariat, and combined with previous IFPMA IVS survey data (2004–2013). Data were available from 201 countries over the 2004–2015 period. A “hurdle” rate was defined as the number of doses required to reach 15.9% of the population in 2008. Overall, the number of distributed doses progressively increased between 2004 and 2011, driven by a 150% increase in AMRO, then plateaued. One percent fewer doses were distributed in 2015 than in 2011. Twenty–three countries were above the hurdle rate in 2015, compared to 15 in 2004, but distribution was highly uneven in and across all WHO regions. Three WHO regions (AMRO, EURO and WPRO) accounted for about 95% of doses distributed. But in EURO and WPRO, distribution rates in 2015 were only marginally higher than in 2004, and in EURO there was an overall downward trend in dose distribution. The vast majority of countries cannot meet the 2003 WHA coverage targets and are inadequately prepared for a global influenza pandemic. With only 5% of influenza vaccine doses being distributed to 50% of the world’s population, there is urgency to redress the gross inequities in disease prevention and in pandemic preparedness. The 2003 WHA resolution must be reviewed and revised and a call issued for the renewed commitment of Member States to influenza vaccination coverage targets.     

Increasing seasonal influenza vaccination among high risk groups in China: Do community healthcare workers have a role to play?

BackgroundSeasonal influenza vaccine uptake in China is low. This study aims to assess the role of community healthcare workers (HCWs) in increasing vaccination among high risk groups in China.MethodsWe analyzed data from four knowledge, attitude and practice (KAP) studies on seasonal influenza vaccination in China targeting guardians of young children, pregnant women, adults aged ≥60 years, and HCWs from 2012 to 2014.ResultsThirty-one percent of pregnant women and 78% adults aged ≥60 years reported willingness to follow HCWs’ recommendations for influenza vaccination. Guardians were more likely to vaccinate their children if they received HCWs’ recommendations (35% vs. 17%, p < 0.001). Community HCWs were more likely to recommend seasonal influenza vaccination than hospital HCWs (58% vs. 28%, p < 0.001).ConclusionStudy results suggest the value of incorporating community HCWs’ recommendation for seasonal influenza vaccination into existing primary public health programs to increase vaccination coverage among high risk groups in China.     

Is annual vaccination best? A modelling study of influenza vaccination strategies in children

IntroductionAnnual vaccination of children against influenza is a key component of vaccination programs in many countries. However, past infection and vaccination may affect an individual’s susceptibility to infection. Little research has evaluated whether annual vaccination is the best strategy. Using the United Kingdom as our motivating example, we developed a framework to assess the impact of different childhood vaccination strategies, specifically annual and biennial (every other year), on attack rate and expected number of infections.Methods and findingsWe present a multi-annual, individual-based, stochastic, force of infection model that accounts for individual exposure histories and disease/vaccine dynamics influencing susceptibility. We simulate birth cohorts that experience yearly influenza epidemics and follow them until age 18 to determine attack rates and the number of infections during childhood. We perform simulations under baseline conditions, with an assumed vaccination coverage of 44%, to compare annual vaccination to no and biennial vaccination. We relax our baseline assumptions to explore how our model assumptions impact vaccination program performance.At baseline, we observed less than half the number of infections between the ages 2 and 10 under annual vaccination in children who had been vaccinated at least half the time compared to no vaccination. When averaged over all ages 0–18, the number of infections under annual vaccination was 2.07 (2.06, 2.08) compared to 2.63 (2.62, 2.64) under no vaccination, and 2.38 (2.37, 2.40) under biennial vaccination. When we introduced a penalty for repeated exposures, we observed a decrease in the difference in infections between the vaccination strategies. Specifically, the difference in childhood infections under biennial compared to annual vaccination decreased from 0.31 to 0.04 as exposure penalty increased.ConclusionOur results indicate that while annual vaccination averts more childhood infections than biennial vaccination, this difference is small. Our work confirms the value of annual vaccination in children, even with modest vaccination coverage, but also shows that similar benefits of vaccination may be obtained by implementing a biennial vaccination program.Author summaryMany countries include annual vaccination of children against influenza in their vaccination programs. In the United Kingdom (UK), annual vaccination of children aged of 2 to 10 against influenza is recommended. However, little research has evaluated whether annual vaccination is the best strategy, while accounting for how past infection and vaccination may affect an individual’s susceptibility to infection in the current influenza season. Prior work has suggested that there may be a negative effect of repeated vaccination. In this work we developed a stochastic, individual-based model to assess the impact of repeated vaccination strategies on childhood infections. Specifically, we first compare annual vaccination to no vaccination and then annual vaccination to biennial (every other year) vaccination. We use the UK as our motivating example. We found that an annual vaccination strategy resulted in the fewest childhood infections, followed by biennial vaccination. The difference in number of childhood infections between the different vaccination strategies decreased when we introduced a penalty for repeated exposures. Our work confirms the value of annual vaccination in children, but also shows that similar benefits of vaccination can be obtained by implementing a biennial vaccination program, particularly when there is a negative effect of repeated vaccinations.     

A cluster of nonspecific adverse events in a military reserve unit following pandemic influenza A (H1N1) 2009 vaccination-Possible stimulated reporting?

Background

On February 20, 2010, a 23 year old male Army Reservist (index case) with symptom onset 4 h after receiving inactivated monovalent pandemic 2009 (H1N1) vaccine (MIV) was hospitalized with possible Guillain-Barré syndrome (GBS). Within 1–2 days, 13 reservists from the same unit presented to the emergency department and 14 filed Vaccine Adverse Event Reporting System (VAERS) reports of nonspecific symptoms following MIV.

Objectives

To describe the spectrum of adverse events (AE) among reservists in the unit after MIV and to identify factors contributing to this cluster of reports.

Methods

We reviewed the reservists’ VAERS reports and hospital records for demographics, influenza vaccination status, diagnostic results and outcome. All VAERS reports after vaccination from the same MIV lot were also screened. We conducted a survey of unit reservists to identify contributing factors for this cluster.

Results

The presumptive diagnosis of GBS in the index case was not confirmed. All other reservists demonstrated normal exam findings and laboratory investigations. VAERS reports following vaccination from the same MIV lot revealed no consistent pattern. Our survey of factors contributing to the cluster was returned by 55 reservists (response rate 28%). AEs following MIV were significantly more often reported by female and black reservists. There was a tendency for concern about the safety of the 2010–2011 seasonal influenza vaccine to be higher for reservists that reported an AE to MIV (p = 0.13) or that sought medical attention for their symptoms (p = 0.08).

Conclusions

This cluster represents possible stimulated reporting following receipt of inactivated pandemic 2009 (H1N1) vaccine among service personnel.     

Priming with MF59 adjuvanted versus nonadjuvanted seasonal influenza vaccines in children – A systematic review and a meta-analysis

BackgroundIdentifying optimal priming strategies for children <2 years could substantially improve the public health benefits of influenza vaccines. Adjuvanted seasonal influenza vaccines were designed to promote a better immune response among young vaccine-naïve children.MethodsWe systematically reviewed randomized trials to assess hemagglutination inhibition (HAI) antibody response to MF59-adjuvanted inactivated influenza vaccine (aIIV) versus nonadjuvanted IIV among children. We estimated pooled ratios of post-vaccination HAI geometric mean titer (GMT) for aIIV versus IIV and confidence intervals (CIs) using the pooled variances derived from reported CIs.ResultsMean age was 28 months (range, 6–72 months). Children received vaccines with either 7.5 μg (6–35 months) or 15 μg (≥36 months) hemagglutinin of each strain depending on age. Seven of eight trials administered trivalent vaccines and one used quadrivalent vaccine. Pooled post-vaccination GMT ratios against the three influenza vaccine strains were 2.5–3.5 fold higher after 2-dose-aIIV versus 2-dose-IIV among children 6–72 months, and point estimates were higher among children 6–35 months compared with older children. When comparing 1-dose-aIIV to 2-dose-IIV doses, pooled GMT ratios were not significantly different against A/H1N1 (1.0; 95% CI: 0.5–1.8; p = 0.90) and A/H3N2 viruses (1.0; 95% CI: 0.7–1.5; p = 0.81) and were significantly lower against B viruses (0.6; 95% CI: 0.4–0.8; p < 0.001) for both age groups. Notably, GMT ratios for vaccine-mismatched heterologous viruses after 2-dose-aIIV compared with 2-dose-IIV were higher against A/H1N1 (2.0; 95% CI: 1.1–3.4), A/H3N2 (2.9; 95% CI: 1.9–4.2), and B-lineage viruses (2.1; 95% CI: 1.8–2.6).ConclusionsTwo doses of adjuvanted IIV consistently induced better humoral immune responses against Type A and B influenza viruses compared with nonadjuvanted IIVs in young children, particularly among those 6–35 months. One adjuvanted IIV dose had a similar response to two nonadjuvanted IIV doses against Type A influenza viruses. Longer-term benefits from imprinting and cell-mediated immunity, including trials of clinical efficacy, are gaps that warrant investigation.     

Increasing healthcare workers’ uptake of seasonal influenza vaccination in a tertiary-care pediatric hospital in Greece with a low-cost,tailor-made,multifaceted strategy

BackgroundHealthcare workers’ (HCW) seasonal influenza vaccination (SIV) is critical to prevent nosocomial influenza. However, HCW vaccination rates remain unacceptably low in many European institutions. A two-year three-step initiative was implemented at a tertiary-care pediatric hospital with 750 beds in Athens, Greece with the aim of increasing SIV among HCW.MethodsΑ cross-sectional anonymous survey of HCWs was conducted during the 2015–16 influenza season with the aim to evaluate attitudes, knowledge, and specific barriers and facilitators for SIV. Stratified analysis was used to identify factors associated with no prior history of influenza vaccination. Multifaceted interventions were implemented in the 2016–2017 season. These included 1) education around influenza disease and SIV, and 2) communication of availability and opportunity (time and place) of SIV. Interventions were designed to target HCWs with the lowest SIV rates in the previous three years.ResultsWe achieved a 67% response rate, with 363 respondents (106 doctors, 145 nurses, 101 other hospital staff; 11 did not provide their profession). Most (64%) had not been vaccinated in the previous three years; only 14% received the vaccine annually. Non-vaccination rates were significantly higher among nurses (76%) and cleaning and food-service workers (73%) compared to doctors (40%) (P < 0.001). Protection of self, family, patients and colleagues were the most common motivations. Concerns about the safety and effectiveness of the vaccine, the belief that one does not belong to a high-risk group were the most common barriers. The interventions led to an increase in SIV uptake by the HCWs in the hospital, from 19% to 31%.ConclusionsIn a country with very low reported rates of vaccination among HCWs, a simple, low-cost, tailor-made intervention strategy can lead to an increase in SIV uptake. Stratifying data according to vaccination history may reveal a diversity of targets for improvement that might otherwise be missed.     

Factors associated with parental acceptance of seasonal influenza vaccination for their children – A telephone survey in the adult population in Germany

IntroductionInfluenza vaccination of children with underlying chronic diseases is currently recommended in Germany, but targeting all children constitutes an alternative approach to control seasonal influenza. To inform the modelling of vaccination impact and possible communication activities, we aimed to assess among parents the acceptance of universal childhood vaccination against seasonal influenza and possible modifiers.MethodsWe conducted a telephone survey in households in Germany using random digit dialing. We interviewed parents with children aged <18 years by constructing three hypothetical scenarios in subsequent order: (1) hearing about the influenza vaccination recommendation through the media, (2) the vaccine being recommended by a physician, and (3) being informed about the availability of the vaccine as a nasal spray. We calculated the proportion of parents who would immunize their child and used univariable and multivariable logistic regression to identify factors associated with influenza vaccination intention.ResultsResponse was between 22 and 46%. Of 518 participants, 74% were female, mean age was 41.3 years. Participants had on average 1.6 children with a mean age of 8.9 years. In scenario 1, 52% of parents would immunize their child, compared to 64% in scenario 2 (p < 0.01) and to 45% in scenario 3 (p = 0.20). Factors independently associated with vaccination acceptance in scenario 1 were previous influenza vaccination of the child or parent (adjusted odds ratio [aOR] 4.5 and 8.6, respectively), perceived severity of influenza (aOR = 5.1) and living in eastern Germany (aOR = 2.4).ConclusionIf seasonal influenza vaccination was recommended for all children, more than half of the parents would potentially agree to immunize their child. Involving physicians in future information campaigns is essential to achieve high uptake. As intranasal vaccine administration is non-invasive and easily done, it remains unclear why scenario 3 was associated with low acceptance among parents, and the underlying reasons should be further explored.     

Does seasonal vaccination affect the clinical presentation of influenza among the elderly? A cross-sectional analysis in the outpatient setting in France, 2003–2014

Vaccine-induced protection against influenza is not optimal, however it has been suggested that the vaccine may reduce the severity of symptoms among those who develop illness despite being vaccinated. We tested this hypothesis within a countrywide, sentinel general practitioners-based surveillance system in France. We included 2277 individuals aged 65 years or older (of whom 1293 had been vaccinated against influenza, 56.8%) who consulted a general practitioner because of an acute respiratory infection (ARI) during 2003–2014. All patients were taken a nasopharyngeal swab, and information was collected on demographic characteristics and symptoms at disease onset. All specimens were tested for respiratory viruses and, if positive for influenza, the virus type and subtype were determined. We compared the average maximum temperature and the frequency of each symptom, between non-vaccinated and vaccinated influenza patients. We then used logistic regression models to calculate the odds of presenting with each symptom between vaccinated vs. non-vaccinated patients, adjusting by age group, virus (sub)type and season. Overall, 675 ARI patients (29.6%) tested positive for influenza. The A(H3) virus caused the majority of cases (55.1%), followed by influenza B (22.9%), A not-subtyped (11.7%), and A(H1) (10.3%) viruses. Compared to non-vaccinated influenza patients, those who had been vaccinated had a slightly reduced maximum temperature and presented less frequently with myalgia, shivering and headache. In stratified analyses, the observed effect was limited to patients infected with A(H3) or type B viruses. After adjusting by age group, virus (sub)type and season, the difference remained statistically significant only for headache, which was less frequent among vaccinated individuals (odds ratio 0.69, 95% confidence intervals 0.48–0.98). In conclusion, the vaccine was found to be modestly associated with less severe clinical presentation of influenza among the elderly. Our findings reinforce the need for influenza vaccines providing better protection.     

Does seasonal influenza vaccination increase the risk of illness with the 2009 A/H1N1 pandemic virus?

This Perspective discusses the following study published in PLoS Medicine: Skowronski DM, De Serres G, Crocroft N, Janjua NZ, Boulianne N, et al. (2010) Association between the 2008-09 Seasonal Influenza Vaccine and Pandemic H1N1 Illness during Spring-Summer 2009 : Four Observational Studies from Canada. PLoS Med 7(4): e1000258. doi:10.1371/journal.pmed.1000258. In three case-control studies and a household transmission cohort, Danuta Skowronski and colleagues find an association between prior seasonal flu vaccination and increased risk of 2009 pandemic H1N1 flu.     

How close are countries of the WHO European Region to achieving the goal of vaccinating 75% of key risk groups against influenza? Results from national surveys on seasonal influenza vaccination programmes, 2008/2009 to 2014/2015

BackgroundInfluenza vaccination is recommended especially for persons at risk of complications. In 2003, the World Health Assembly urged Member States (MS) to increase vaccination coverage to 75% among older persons by 2010.ObjectiveTo assess progress towards the 2010 vaccination goal and describe seasonal influenza vaccination recommendations in the World Health Organization (WHO) European Region.MethodsData on seasonal influenza vaccine recommendations, dose distribution, and target group coverage were obtained from two sources: European Union and European Economic Area MS data were extracted from influenza vaccination surveys covering seven seasons (2008/2009–2014/2015) published by the Vaccine European New Integrated Collaboration Effort and European Centre for Disease Prevention and Control. For the remaining WHO European MS, a separate survey on policies and uptake for all seasons (2008/2009–2014/2015) was distributed to national immunization programmes in 2015.ResultsData was available from 49 of 53 MS. All but two had a national influenza vaccination policy. High-income countries distributed considerably higher number of vaccines per capita (median; 139.2 per 1000 population) compared to lower-middle-income countries (median; 6.1 per 1000 population). Most countries recommended vaccination for older persons, individuals with chronic disease, healthcare workers, and pregnant women. Children were included in < 50% of national policies. Only one country reached 75% coverage in older persons (2014/2015), while a number of countries reported declining vaccination uptake. Coverage of target groups was overall low, but with large variations between countries. Vaccination coverage was not monitored for several groups.ConclusionsDespite policy recommendations, influenza vaccination uptake remains suboptimal. Low levels of vaccination is not only a missed opportunity for preventing influenza in vulnerable groups, but could negatively affect pandemic preparedness. Improved understanding of barriers to influenza vaccination is needed to increase uptake and reverse negative trends. Furthermore, implementation of vaccination coverage monitoring is critical for assessing performance and impact of the programmes.     

Does dietary calcium have a protective effect on bone fractures in women? A meta-analysis of observational studies

It is generally accepted that supplemental Ca and/or vitamin D is effective in reducing the incidence of bone fractures; this is supported by numerous randomised controlled trials and meta-analyses. However, a question that has received much less attention is whether dietary Ca, i.e. Ca in physiological doses in normal food intake, also affects bone fracture risk. The present study aims to review the effect of dietary Ca on bone fractures at the hip, spine and radius in women >35 years old, and to compare these results with previous meta-analyses. MEDLINE (1966-1999) and reference lists in papers were searched for observational dietary Ca studies. Data were extracted in duplicate and separately. Heterogeneity and publication bias were tested. Observational studies failed to show any association between dietary Ca intake and risk of hip fracture (risk ratio 1.01, 95 % CI 0.96, 1.07 for each increment of 300 mg dietary Ca intake/d). There is a suggestion that either extremely low Ca intake may increase fracture risk, or that East Asian women may respond differently to increasing Ca intake.     

Does a population survey provide reliable influenza vaccine uptake rates among high-risk groups? A case-study of The Netherlands

All European countries have recommendations for influenza vaccination among the elderly and chronically ill. However, only a few countries are able to provide data on influenza uptake among these groups. The aim of our study is to investigate whether a population survey is an effective method of obtaining vaccination uptake rates in the different risk groups and to find out what reasons people give as to why they have accepted or refused influenza vaccination and whether this varies among the risk groups. A mail questionnaire was sent out to households in The Netherlands, the response rate was 73%. This resulted in data for 4037 individuals on influenza and influenza vaccination during the 2001-2002 influenza season. The uptake rates and size of different risk groups from the panel survey were comparable with other national representative sources (from the National Information Network of GPs (LINH) and Statistics Netherlands (CBS)). The main reason cited for undergoing vaccination was the existence of a chronic condition. The main reasons for refraining from vaccination were having enough resistance to flu and ignorance about the recommendations. In The Netherlands, the GP is the main administrator of influenza vaccines. We believe that population surveys may be useful for revealing influenza vaccination uptake rates for the groups at risk. When combined with questions about reasons for undergoing vaccination, the results may provide useful policy information and can be used to direct vaccination campaigns at under-vaccinated risk groups or to target the information campaign more effectively.     

Is remission of depressive symptoms in primary care a realistic goal? A meta-analysis

Background  

A primary goal of acute treatment for depression is clinical remission of symptoms. Most meta-analyses of remission rates involve randomized controlled trials (RCTs) using patients from psychiatric settings, but most depressed patients are treated in primary care. The goal of this study was to determine remission rates obtained in RCTs of treatment interventions for Major Depressive Disorder (MDD) conducted in primary care settings.     

Is there a difference in the immune response,efficacy, effectiveness and safety of seasonal influenza vaccine in males and females? – A systematic review

IntroductionSeasonal influenza is an important cause of morbidity and mortality, despite being vaccine-preventable. Sex factors (genes and hormones) seem to impact individuals’ susceptibility to infectious diseases and their response to vaccination. However, most vaccine studies do not explicitly assess sex differences in vaccine response, but rather adjust for sex.MethodsWe conducted a systematic review to analyze immunogenicity, efficacy, effectiveness and/or safety of seasonal influenza vaccine data stratified by sex. We searched PubMed, EMBASE, CINAHL, Web of Science and clinicaltrials.gov for observational studies and phase III/IV trials from January 1990 to June 2018, published in English or French. Two reviewers independently screened all references, then proceeded to data extraction and quality assessment using the Cochrane tools (RoB and ROBINS-I) on included studies.ResultsOf the 5,745 citations retrieved, 46 studies were included in the SR. Overall, 18 studies assessed immunogenicity, 1 estimated efficacy, 6 measured effectiveness and 25 evaluated safety of seasonal influenza vaccine in females and males (four studies reported on two sex-stratified outcomes concomitantly).ConclusionNo clear conclusion could be drawn regarding the effect of sex on the immunogenicity and effectiveness of seasonal influenza vaccine, but higher rates of adverse events following immunization (AEFIs) were reported in females. The heterogeneity of data and studies’ low quality prevented us from conducting a meta-analysis. There is a need to emphasize on the appropriate use of the terms sex and gender in biomedical research. Evidence of higher quality is needed to better understand sex differences in response to influenza vaccine.     

Won't you stay just a little bit longer? A discrete choice experiment of UK doctors’ preferences for delaying retirement

Introduction and aimsHealth systems around the world face difficulties retaining their workforce, which is exacerbated by the early retirement of experienced clinicians. This study aims to determine how to incentivise doctors to delay their retirement.MethodsWe used a discrete choice experiment to estimate the relative importance of job characteristics in doctors’ willingness to delay retirement, and the number of extra years they were willing to delay retirement when job characteristics improved. 2885 British Medical Association members aged between 50 and 70 years, registered with the General Medical Council, practising in Scotland (in December 2019), and who had not started to draw a pension were invited. We compared the preferences of hospital doctors (HDs) and general practitioners (GPs).ResultsThe response rate was 27.4% (n = 788). The number of extra years expected to work was the most important job characteristic for both respondents, followed by work intensity for GPs, whereas working hours and on-call were more important for HDs. Personalised working conditions and pension taxation were the least important characteristics for both groups. Setting all characteristics to their BEST levels, GPs would be willing to delay retirement by 4 years and HDs by 7 years.ConclusionsCharacteristics related to the job rather than pension could have the greatest impact on delaying retirement among clinicians.     

Impact of varicella vaccination on health care outcomes in Ontario, Canada: effect of a publicly funded program?

Varicella vaccines have been available for private purchase in Canada since 1998. Ontario introduced publicly funded varicella vaccination in 2004. We assessed the effects of private availability of varicella vaccines and subsequent implementation of a publicly funded vaccination program on varicella-related hospitalizations, emergency department (ED) use, and visits to physicians' offices in Ontario. Rates of hospitalizations, ED use, and office visits decreased 53% (95% CI, 48-58%), 43% (95% CI, 41-44%), and 45% (95% CI, 44-45%) after publicly funded vaccination, compared to only 9% (95% CI, 4-14%), 23% (95% CI, 22-24%), and 29% (95% CI, 28-29%) after private availability. Varicella vaccination is effective at reducing varicella-related health care use, with benefits extending beyond those who receive the vaccine. Publicly funded vaccination programs may be more effective than private vaccine availability.     

Safety and immunogenicity of a seasonal quadrivalent influenza vaccine (GC3110A) in healthy participants aged ≥ 65 years

BackgroundSeasonal Influenza is still considered associated with seasonal morbidity and hospitalization in the elderly population. The World Health Organization (WHO) recommended seasonal quadrivalent influenza vaccine (QIV) to reduce burden of two currently circulating influenza B lineages. Until 2019 Korean National Immunization Program (NIP) recommended trivalent influenza vaccine (TIV) after ongoing debates on cost effectiveness of QIV for elderly population. Although influenza vaccine only showed modest effect on reducing influenza in elderly, this study aimed to evaluate the immunogenicity and safety of inactivated QIV in healthy participants ≥ 65 years of age.MethodsA total of 274 healthy participants aged ≥ 65 years received a QIV. Seroconversion-based vaccine efficacy of 4 strains of seasonal influenza was assessed 21 days after vaccination and adverse events were monitored until 180 days after vaccination.ResultsThe percentages of participants seroconverted after vaccination on HI antibody against each strain were 36.5% (99/271) to A/H1N1, 47.6% (129/271) to A/H3N2, 40.6% (110/271) to B Yamagata, and 49.1% (133/271) to B Victoria. The percentages of participants seroprotected after vaccination on HI antibody against each strain were 81.2% (220/271) to A/H1N1, 98.5% (267/271) to A/H3N2, 95.2% (258/271) to B Yamagata, and 93.7% (254/271) to B Victoria. There was no serious adverse event (SAE) related with the study vaccine.ConclusionThe quadrivalent split influenza vaccine is expected to offer seroprotection against influenza A and both influenza B lineages even in the elderly population.     

Absenteeism in schools during the 2009 influenza A(H1N1) pandemic: a useful tool for early detection of influenza activity in the community?

Certain influenza outbreaks, including the 2009 influenza A(H1N1) pandemic, can predominantly affect school-age children. Therefore the use of school absenteeism data has been considered as a potential tool for providing early warning of increasing influenza activity in the community. This study retrospectively evaluates the usefulness of these data by comparing them with existing syndromic surveillance systems and laboratory data. Weekly mean percentages of absenteeism in 373 state schools (children aged 4-18 years) in Birmingham, UK, from September 2006 to September 2009, were compared with established syndromic surveillance systems including a telephone health helpline, a general practitioner sentinel network and laboratory data for influenza. Correlation coefficients were used to examine the relationship between each syndromic system. In June 2009, school absenteeism generally peaked concomitantly with the existing influenza surveillance systems in England. Weekly school absenteeism surveillance would not have detected pandemic influenza A(H1N1) earlier but daily absenteeism data and the development of baselines could improve the timeliness of the system.     

Are medical residents a "core group" for future improvement of influenza vaccination coverage in health-care workers? A study among medical residents at the University Hospital of Palermo (Sicily)

Despite international recommendations, vaccination coverage among European healthcare workers, including physicians, is widely recognized as unsatisfactory. In order to plan tailored vaccination campaigns and increase future coverage, we investigated reasons for refusing vaccination and determinants associated with influenza vaccine uptake among young health care workers.A survey was carried out during September and October 2010 on medical residents attending post-graduate Schools of the Medical Faculty at the University of Palermo (Italy). Each participant completed an anonymous web-based questionnaire including items on demographic and occupational characteristics, knowledge, attitudes and behaviours with regard to influenza and influenza vaccination, and main sources of information.A total of 202 (66.9%) out of 302 medical residents participated in the survey. During the 2009-2010 influenza vaccine campaign, 44 residents (21.8%) were vaccinated against seasonal influenza and 84 (41.6%) against pandemic influenza A (H1N1) 2009. For the impending 2010-2011 influenza season, 45 (22.3%) stated their intention to get vaccinated against seasonal influenza, 40 (19.8%) were uncertain and 117 (57.9%) were opposed. Considering themselves to be a high risk group for developing influenza was significantly associated with vaccination against both 2009-2010 seasonal (adj-OR = 1.46; 95% CI = 1.05-2.04) and pandemic A (H1N1) influenza (adj-OR 1.38; 95% CI = 1.08-1.75). Intention to get vaccinated against 2010-2011 seasonal influenza was significantly more frequent in participants who had a high perception of efficacy/safety (adj-OR = 1.49; 95% CI = 1.05-2.12). After adjusting for confounding, vaccinations against seasonal 2009-2010 influenza, pandemic influenza A (H1N1) 2009 and seasonal 2010-2011 influenza were significantly more frequent in residents who were vaccinated against influenza at least once in the previous five influenza seasons.Influenza vaccination among medical residents appears to be habitual, with little comprehension of the rationale and logic for vaccination, including the need to be vaccinated to protect patients from nosocomial influenza infection. Our study suggests the importance of prioritizing residents for vaccination campaigns, as they represent “the future” and include a core group that habitually accepts vaccination.