Risk Of Influenza Infection Research Articles

Cross-protection to new drifted influenza A(H3) viruses and prevalence of protective antibodies to seasonal influenza, during 2014 in Portugal

IntroductionImmune profile for influenza viruses is highly changeable over time. Serological studies can assess the prevalence of influenza, estimate the risk of infection, highlight asymptomatic infection rate and can also provide data on vaccine coverage. The aims of the study were to evaluate pre-existing cross-protection against influenza A(H3) drift viruses and to assess influenza immunity in the Portuguese population. Materials and methodsWe developed a cross-sectional study based on a convenience sample of 626 sera collected during June 2014, covering all age groups, both gender and all administrative health regions of Portugal. Sera antibody titers for seasonal and new A(H3) drift influenza virus were evaluated by hemagglutination inhibition assay (HI). Seroprevalence to each seasonal influenza vaccine strain virus and to the new A(H3) drift circulating strain was estimated by age group, gender and region and compared with seasonal influenza-like illness (ILI) incidence rates before and after the study period. ResultsOur findings suggest that seroprevalences of influenza A(H3) (39.9%; 95% CI: 36.2–43.8) and A(H1)pdm09 (29.7%; 95% CI: 26.3–33.4) antibodies were higher than for influenza B, in line with high ILI incidence rates for A(H3) followed by A(H1)pdm09, during 2013/2014 season. Low pre-existing cross-protection against new A(H3) drift viruses were observed in A(H3) seropositive individuals (46%). Both against influenza A(H1)pdm09 and A(H3) seroprotection was highest in younger than 14-years old. Protective antibodies against influenza B were highest in those older than 65years old, especially for B/Yamagata lineage, 33.3% (95% CI: 25.7–41.9). Women showed a high seroprevalence to influenza, although without statistical significance, when compared to men. A significant decreasing trend in seroprotection from north to south regions of Portugal mainland was observed. ConclusionsOur results emphasize that low seroprotection increases the risk of influenza infection in the following winter season. Seroepidemiological studies can inform policy makers on the need for vaccination and additional preventive measures.

Influenza vaccination in older people with diabetes and their household contacts

BackgroundPeople with diabetes are at a higher risk of influenza infections and severe complications. The vaccination of close contacts could offer indirect protection to people with diabetes; this is known as “herd immunity.” The aim of this study is to investigate the vaccination rates of people with diabetes and their household contacts in Hong Kong. Research design and methodsFace-to-face interviews with 158 patients diagnosed with Type 2 diabetes and aged ⩾65years were conducted in clinics. Telephone interviews were then conducted with 281 adult household contacts. ResultsSeasonal influenza vaccination rates were 54.5% and 27.4%, in people with diabetes and their contacts, respectively. The vaccination status of patients was not significantly associated with the vaccination of their household contacts (p=0.073). Among household contacts, children or the elderly, the partners or couples of patients, and those with more hours of daily contact, or with chronic conditions, were associated with higher vaccination rates. However, only age remained significant after adjusting for confounding factors in logistic regression models. ConclusionsThe low vaccination rates of people with diabetes and their close contacts highlight the need to promote vaccination in susceptible populations and to educate the public about herd immunity.

Determinants of seasonal influenza vaccination in pregnant women in Valencia, Spain.

BackgroundIn most countries the coverage of seasonal influenza vaccination in pregnant women is low. We investigated the acceptance, reasons for rejection and professional involvement related to vaccine information in pregnant women in Valencia, Spain.MethodsObservational retrospective study in 200 pregnant women, 100 vaccinated and 100 unvaccinated, were interviewed during the 2014/2015 vaccination campaign. Electronic medical records, immunization registry and telephone interviews were used to determine reasons for vaccination and immunization rejection.Results40.5% of pregnant women in the health department were vaccinated. The midwife was identified as source of information for 89% of women. The vaccine was rejected due to low perceptions of risk of influenza infection (23%), lack of information (19%), considering the vaccine as superfluous (16%), close proximity of delivery date (13%) and fear of side effects (12%).ConclusionPregnant women in Spain declined to be vaccinated due to under-estimation of the risk of contracting or being harmed by influenza, and lack of information. Interventions aiming to optimize vaccination coverage should include information addressing the safety and effectiveness of the current vaccine together with improved professional training and motivation.

Influenza vaccination motivators among healthcare personnel in a large acute care hospital in Israel.

BackgroundVaccinating healthcare personnel (HCP) against influenza is important to prevent transmission and morbidity among patients and staff.MethodsWe conducted an online survey assessing knowledge, perceptions and attitudes concerning influenza vaccination among HCP. Multivariate logistic regression was performed to identify independent predictors of vaccination.ResultsThe survey was completed by 468 HCP representing all categories of staff. Doctors believed that vaccination was the best way to prevent influenza and perceived the vaccine less harmful as compared to nurses and allied health professionals. Getting vaccinated was associated with a greater likelihood of recommending vaccination to patients: 86 % vs. 54 % in vaccinated and unvaccinated HCP, respectively. Reasons for vaccine refusal were fear of needles (19 %); fear of side effects (66 %) and lack of time (16 %). In the multivariate analysis, survey items that were independently associated with vaccination were beliefs that: vaccine effectively prevents influenza (OR 4.07 95 % CI 2.51, 6.58); HCP are at increased risk of influenza (OR 2.82 95 % CI 1.56, 5.13); vaccine can cause influenza (OR 0.41 95 % CI 0.25, 0.65); contracting influenza is likely in the absence of vaccination (OR 1.96 95 % CI 1.12, 3.42); and that HCP might transmit influenza to their family (OR 4.54 95 % CI 1.38, 14.97). The belief that HCP might transmit influenza to patients was not independently associated with vaccine uptake.ConclusionOur study revealed misconceptions and knowledge gaps concerning the risk of influenza and the influenza vaccine. There were significant differences in knowledge and attitudes between healthcare professions. HCP decline vaccination because they do not perceive a personal risk of influenza infection and are concerned about side effects. Thus, in order to increase vaccination rates it is important to educate HCP to correct misconceptions concerning vaccine efficacy and safety, while promoting the benefit of getting vaccinated in order to protect themselves and their families.

Influenza immunization among Canadian health care personnel: a cross-sectional study

Influenza immunization coverage among Canadian health care personnel remains below national targets. Targeting this group is of particular importance given their elevated risk of influenza infection, role in transmission and influence on patients' immunization status. We examined influenza immunization coverage in health care personnel in Canada, reasons for not being immunized and the impact of "vaccinate-or-mask" influenza prevention policies. In this national cross-sectional study, we pooled data from the 2007 to 2014 cycles of the Canadian Community Health Survey and restricted it to respondents who reported a health care occupation. Using bootstrapped survey weights, we examined immunization coverage by occupation and by presence of vaccinate-or-mask policies, and reasons for not being immunized. We used modified Poisson regression to estimate the prevalence ratio (PR) of influenza immunization for health care occupations compared with the general working population. For all survey cycles combined, 50% of 18 446 health care personnel reported receiving seasonal influenza immunization during the previous 12 months, although this varied by occupation type (range 4%-72%). Compared with the general working population, family physicians and general practitioners were most likely to be immunized (PR 3.15, 95% confidence interval [CI] 2.76-3.59), whereas chiropractors, midwives and practitioners of natural healing were least likely (PR 0.17, 95% CI 0.10-0.30). Among those who were not immunized, the most frequently cited reason was the belief that influenza immunization is unnecessary. Introduction of vaccinate-or-mask policies was associated with increased influenza immunization among health care personnel. Health care personnel are more likely to be immunized against influenza than the general working population, but coverage remains suboptimal overall, and we observed wide variation by occupation type. More efforts are needed to target specific health care occupations with low immunization coverage.

A randomized trial of maternal influenza immunization decision-making: A test of persuasive messaging models

ABSTRACTObjective: We sought to examine the effectiveness of persuasive communication interventions on influenza vaccination uptake among black/African American pregnant women in Atlanta, Georgia. Methods: We recruited black/African American pregnant women ages 18 to 50 y from Atlanta, GA to participate in a prospective, randomized controlled trial of influenza immunization messaging conducted from January to April 2013. Eligible participants were randomized to 3 study arms. We conducted follow-up questionnaires on influenza immunization at 30-days post-partum with all groups. Chi-square and t tests evaluated group differences, and outcome intention-to-treat assessment utilized log-binomial regression models. Results: Of the 106 enrolled, 95 women completed the study (90% retention), of which 31 were randomly assigned to affective messaging intervention (“Pregnant Pause” video), 30 to cognitive messaging intervention (“Vaccines for a Healthy Pregnancy” video), and 34 to a comparison condition (receipt of the Influenza Vaccine Information Statement). The three groups were balanced on baseline demographic characteristics and reported health behaviors. At baseline, most women (63%, n = 60) reported no receipt of seasonal influenza immunization during the previous 5 y. They expressed a low likelihood (2.1 ± 2.8 on 0-10 scale) of obtaining influenza immunization during their current pregnancy. At 30-days postpartum follow-up, influenza immunization was low among all participants (7-13%) demonstrating no effect after a single exposure to either affective messaging (RR = 1.10; 95% CI: 0.30-4.01) or cognitive messaging interventions (RR = 0.57; 95% CI: 0.11-2.88). Women cited various reasons for not obtaining maternal influenza immunizations. These included concern about vaccine harm (47%, n = 40), low perceived influenza infection risk (31%, n = 26), and a history of immunization nonreceipt (24%, n = 20). Conclusion: The findings reflect the limitations associated with a single exposure to varying maternal influenza immunization message approaches on vaccine behavior. For this population, repeated influenza immunization exposures may be warranted with alterations in message format, content, and relevance for coverage improvement.

Perceptions of influenza vaccination during pregnancy in Korean women of childbearing age

ABSTRACTThe rate of maternal influenza vaccination in Korea is much lower than the general population. We evaluated the influenza vaccination rate during pregnancy and assessed women's perceptions of the influenza vaccine. One thousand women of childbearing age were surveyed from April through May 2014, using a questionnaire about vaccination history, general understanding of influenza vaccination and that examined factors that influence decisions about influenza vaccination. We also conducted an intervention to evaluate potential improvement in vaccination behavior. The influenza vaccination rate during pregnancy was 37.3%. The common reasons listed in support of vaccination included the perception of the risk of influenza infection, recommendations from health care providers, and belief in the effectiveness of the influenza vaccine. The most common reasons for not vaccinating included concern about harmful effects and the lack of recommendation from health care providers. Based on the results of the questionnaire and intervention, it is important to provide accurate information and for health care providers to recommend the influenza vaccine to pregnant women. It is also necessary for the government to encourage women to receive the influenza vaccination as a healthcare policy.

Effect of gargling with tea and ingredients of tea on the prevention of influenza infection: a meta-analysis.

BackgroundInfluenza viruses can spread easily from person to person, and annual influenza epidemics are serious public health issues worldwide. Non-pharmaceutical public health interventions could potentially be effective for combatting influenza epidemics, but combined interventions and/or interventions with greater effectiveness are needed. Experimental studies have reported that tea and its ingredients (especially catechins) have antiviral activities. Although several clinical studies have investigated the use of tea or its ingredients to prevent influenza infections, the effect of gargling these substances has remained uncertain.MethodsWe conducted a meta-analysis of randomized controlled studies and prospective cohort studies to assess the effect of gargling with tea and its ingredients on the prevention of influenza infection. The published literature was searched using the Cochrane Library, PubMed/MEDLINE (1966 to September 2015), Web of Science (1981 to September 2015), and Ichu-shi Web (1983 to September 2015). The extracted studies were read by two reviewers independently, and their overall scientific quality was evaluated. Studies meeting our inclusion criteria were pooled using the Mantel-Haenszel method in a fixed effects model and were also analyzed in a random effects model. The qualities of the model fits were assessed using the Akaike information criterion (AIC) and Bayesian information criterion (BIC).ResultsThe literature search and review identified 5 studies that met the inclusion criteria for the meta-analysis (total number of participants, 1890; mean age range, 16–83 years). The participants who gargled with tea or its ingredients showed a lower risk of influenza infection than did participants who gargled with placebo/water or who did not gargle (fixed effects model, Mantel-Haenszel method: relative risk [RR] = 0.70, 95 % confidence interval [CI] = 0.54–0.89; random effects model: RR = 0.71, 95 % CI = 0.56–0.91). The fixed effects model had a better quality of fit than the random effects model (fixed effects model: AIC = 6.04, BIC = 5.65; random effects model: AIC = 8.74, BIC = 7.52).ConclusionsGargling with tea and its ingredients may have a preventative effect for influenza infection. However, additional large-scale studies in different populations and a pooled analysis of these studies are needed to confirm the effect.

Effect of risk factors on the prevalence of influenza infections among children of slums of Dhaka city.

BackgroundInfluenza viruses may cause severe acute respiratory illness among human population. People of densely populated areas, e.g., slum, are mostly affected by influenza viruses. Although potential vaccines to influenza viruses have been developed, infection rate is still high, therefore, increase the morbidity and mortality rate in slum areas. To treat these infections, slum dwellers including children and mothers do not get proper medication as well as vaccination. Hence, prevention remains to be the only mean to tackle such infections. Herein, we determined the prevalence of influenza infections among nutritionally deprived children and mothers of slum areas in Dhaka city and demonstrated the association with different risk factors like age, gender and socio-economic status.ResultsNasopharyngeal swab samples and a short demography of all the participants suffering from influenza-like illness (ILI) were collected. The samples were subjected to RNA extraction and then real-time RT-PCR to detect influenza viruses. Among the ILI patients, about 87.9 % did not have knowledge about influenza infections and 80.5 % did not cover their noses during coughing as well as sneezing. Children were significantly infected by both influenza A and influenza B viruses, suggesting their vulnerability to these infections. Additionally, among the children with ILI, influenza infections were significantly associated with age below or equal to three years, very poor family incomes, practicing unhygienic habits and nutritional deficiency.ConclusionsThis study suggests that proper vaccination, improved sanitary conditions and nutritional diet may help reduce the risk of influenza infections in slum areas.

Effectiveness of maternal influenza immunization in young infants in Japan.

Infants with influenza, particularly those younger than 1 year of age, are at high risk of developing a severe case or of dying. Recently, owing to the spread of pandemic influenza A (H1N1) 2009, the Advisory Committee on Immunization Practices recommended maternal immunization to reduce the risk of influenza infection in pregnant women and infants. Such reporting is rare in Japan. The aim of this study was therefore to investigate the effect on the newborn of influenza vaccination of pregnant women in Japan. The study included 200 infants who were born to healthy mothers at Kobayashi Ladies Clinic during influenza season from November 2010 to April 2011. The incidence of fever and laboratory-confirmed influenza was assessed in the infants for the 6 months after their birth. Of the 200 infants, four were excluded from this study due to loss to follow up. The 106 infants in the group whose mothers received the influenza vaccine (vaccinated group) before parturition were compared with the 90 infants in the group whose mothers did not receive the influenza vaccine (non-vaccinated group). Fever was noted in 36 infants (34.0%) in the vaccinated group and in 47 infants (52.2%) in the non-vaccinated group (P < 0.007), and the incidence of influenza was 0 (0%) and 5 (5.6%), respectively (P = 0.019). The incidence of fever and influenza among infants was significantly lower in the vaccinated group compared with the non-vaccinated group. Maternal influenza immunization should be actively recommended in Japan to protect newborns from influenza viruses.

Protective Effect of Hand-Washing and Good Hygienic Habits Against Seasonal Influenza: A Case-Control Study.

Previous observational studies have reported protective effects of hand-washing in reducing upper respiratory infections, little is known about the associations between hand-washing and good hygienic habits and seasonal influenza infection. We conducted a case-control study to test whether the risk of influenza transmission associated with self-reported hand-washing and unhealthy hygienic habits among residents in Fujian Province, southeastern China.Laboratory confirmed seasonal influenza cases were consecutively included in the study as case-patients (n = 100). For each case, we selected 1 control person matched for age and city of residence. Telephone interview was used to collect information on hand-washing and hygienic habits. The associations were analyzed using conditional logistic regression.Compared with the poorest hand-washing score of 0 to 3, odds ratios of influenza infection decreased progressively from 0.26 to 0.029 as hand-washing score increased from 4 to the maximum of 9 (P < 0.001). Compared with the poorest hygienic habit score of 0 to 2, odds ratios of influenza infection decreased from 0.10 to 0.015 with improving score of hygienic habits (P < 0.001). Independent protective factors against influenza infection included good hygienic habits, higher hand-washing score, providing soap or hand cleaner beside the hand-washing basin, and receiving influenza vaccine.Regular hand-washing and good hygienic habits were associated with a reduced risk of influenza infection. These findings support the general recommendation for nonpharmaceutical interventions against influenza.

Perceptions of Hong Kong Chinese women toward influenza vaccination during pregnancy

IntroductionPregnant women are the highest priority group for seasonal influenza vaccination. However, their vaccination uptake remains suboptimal. The purpose of this study is to explore Hong Kong women's perceptions of the threat of influenza infection during pregnancy, the risks and benefits of influenza vaccination, and their decision-making processes. MethodsWe used a qualitative descriptive design and recruited women who had just given births to a live infant from April to June 2011. Participants were recruited from a large teaching hospital in Hong Kong and were interviewed in the immediate postpartum period. ResultsA total of 32 postpartum women were interviewed, and two had been vaccinated during pregnancy. Following thematic analysis, three themes emerged: perceived risk of influenza infection, perceived risk of influenza vaccine, and decision-making cues. Overall, participants held negative impressions about influenza vaccination during pregnancy, and they underestimated the threat of influenza to themselves and their fetus. They were also confused about the safety and efficacy of the influenza vaccine and the differences between preventive strategies and treatment for influenza. Most participants reported that their health care providers (HCPs) did not offer or recommend vaccination. Because of negative media reports about vaccination, participants were hesitant to receive the vaccine. Motivating forces for vaccine acceptance were a perceived high prevalence of circulating influenza during their pregnancy and HCP recommendations and reassurances that the vaccination was safe, effective, and beneficial for the fetus. ConclusionVaccination promotion strategies need to focus on encouraging HCPs to take the initiative to discuss vaccination with their pregnant clients and provide accurate and unbiased information about the risks of influenza and the benefits of vaccination.

Knowledge and practice about influenza vaccination and compliance with influenza immunization among pregnant women in Sari, 2013

Background and Purpose: Pregnant women are at a higher risk of influenza infection, and influenza vaccination is recommended for these women to reduce the associated complications. This study aimed to determine the knowledge and practice about influenza vaccination and identify the factors influencing compliance with influenza immunization among pregnant women. Methods: This cross-sectional study was conducted on 384 pregnant women referring to six health care centers and six obstetric clinics in 2013 in Sari, Mazandaran, Iran. After the random selection of health care centers, samples were collected using convenience sampling. The objectives of the study were explained to the participants, and questionnaires were completed on the demographic characteristics, knowledge and practice in influenza vaccination. Data analysis was performed using frequency, mean, standard deviation, Chi-square test, Friedman test and T-test in SPSS V.14. Results: In this study, general knowledge of pregnant women about influenza vaccination was relatively poor. Approximately 31% of the studied subjects had low awareness, while 52% and 18% had moderate and high levels of knowledge about influenza immunization. In addition, rate of influenza vaccination was estimated at 5.5%, and the most common reason for avoiding vaccination during pregnancy was the concern about the possible risks of the vaccine for the fetus (34.9%). Conclusion: According to the results of this study, pregnant women are not adequately informed about influenza vaccination and its benefits; therefore, the overall rate of influenza vaccination is low. In this regard, educational programs on influenza complications, benefits of maternal vaccination and vaccine safety should be implemented for pregnant women by health professionals.

Outbreak of Influenza A(H1N1) in a Kidney Transplant Unit—Protective Effect of Vaccination

Seasonal influenza vaccination is recommended for patients with end-stage renal disease (ESRD), despite suggested inferior efficacy among these patients. We characterize an outbreak of influenza A(H1N1) in a kidney transplant unit. Altogether 23 patients were treated on the ward for postoperative care after kidney transplantation during the outbreak. After the first positive case, all patients were tested with nasopharyngeal swab tests and 7 patients were diagnosed with influenza A(H1N1). Altogether 17/23 patients had received adequate seasonal influenza vaccination, of whom 2/17 tested positive for influenza (one asymptomatic, one with mild cough). Five of six unvaccinated patients were diagnosed with influenza A(H1N1); 3/5 suffered from severe respiratory failure and were treated with ventilator support in the ICU, but all died due to acute respiratory distress syndrome, whereas 2/5 suffered from mild viral pneumonitis and recovered fully. The risk of influenza infection and mortality was significantly increased in unvaccinated patients (odds ratio 37.5 [95% CI 2.7-507.5, p = 0.01] and 6.7 [95% CI 2.3-18.9, p = 0.003], respectively). Influenza A(H1N1) had a high mortality in our cohort of nonvaccinated immunosuppressed patients early after kidney transplantation. None of the vaccinated patients developed serious disease, supporting the role of vaccination also for ESRD patients.

Review on the effects of influenza vaccination during pregnancy on preterm births

Pregnant women are considered to be susceptible to severe influenza illness and are recommended as a priority group to be targeted for influenza vaccination in countries with vaccination programs. Increased rates of poor birth outcomes have also been temporally associated with influenza infection, especially when pandemics strains emerge. Even though the primary purpose for influenza vaccination during pregnancy is to decrease the risk of influenza infection in the women, other potential benefits include protection of their young infants against influenza illness and possibly improving birth outcomes. The 2009 influenza A/H1N1 pandemic highlighted the importance of influenza vaccination during pregnancy, after pregnant women were identified as a group with heightened morbidity and mortality during the pandemic. A few studies conducted before the 2009/10 season and a large number of reports during and after the 2009 pandemic have assessed the association between maternal influenza vaccination and birth outcomes. Although these studies indicate that influenza vaccination is safe for both the mother and the fetus, there are conflicting data on the effect of vaccination in improving preterm birth rates. We reviewed the 2 published randomized control trials and other observational studies that explored the relationship between maternal influenza vaccination and preterm births.

Assessing coughing-induced influenza droplet transmission and implications for infection risk control.

Indoor transmission of respiratory droplets bearing influenza within humans poses high risks to respiratory function deterioration and death. Therefore, we aimed to develop a framework for quantifying the influenza infection risk based on the relationships between inhaled/exhaled respiratory droplets and airborne transmission dynamics in a ventilated airspace. An experiment was conducted to measure the size distribution of influenza-containing droplets produced by coughing for a better understanding of potential influenza spread. Here we integrated influenza population transmission dynamics, a human respiratory tract model, and a control measure approach to examine the indoor environment-virus-host interactions. A probabilistic risk model was implemented to assess size-specific infection risk for potentially transmissible influenza droplets indoors. Our results found that there was a 50% probability of the basic reproduction number (R0) exceeding 1 for small-size influenza droplets of 0·3-0·4 µm, implicating a potentially high indoor infection risk to humans. However, a combination of public health interventions with enhanced ventilation could substantially contain indoor influenza infection. Moreover, the present dynamic simulation and control measure assessment provide insights into why indoor transmissible influenza droplet-induced infection is occurring not only in upper lung regions but also in the lower respiratory tract, not normally considered at infection risk.

Persistence and avidity maturation of antibodies to A(H1N1)pdm09 in healthcare workers following repeated annual vaccinations

Healthcare workers are at increased risk of influenza infection through direct patient care, particularly during the early stages of a pandemic. Although influenza vaccination is widely recommended in Healthcare workers, data on long-term immunogenicity of vaccination in healthcare workers are lacking.The present study was designed to assess the persistence of the humoral response after pandemic vaccination as well as the impact of repeated annual vaccination in healthcare workers (n=24).Pandemic influenza vaccination resulted in a significant increase in haemagglutination inhibition (HI) antibody titers with 93–100% of subjects achieving protective titers 21-days post each of the three annual vaccinations. Seroprotective antibodies measured by HI, microneutralization and single radial hemolysis assays were present in 77–94% of healthcare workers 6 months post-vaccination. Repeated vaccination resulted in an increased duration of seroprotective antibodies with seroprotective titers increasing from 35–62% 12 months after 2009 pandemic vaccination to 50–75% 12 months after 2010 vaccination. Furthermore, repeated annual vaccination augmented the avidity of influenza-specific IgG antibodies.In conclusion, we have shown that A(H1N1)pdm09 vaccination induces high seroprotective titers that persist for at least 6 months. We demonstrate that repeated vaccination is beneficial to healthcare workers and results in further avidity maturation of vaccine-induced antibodies.

Influenza Vaccine Antibody Response and 6-month Persistence in Lung Transplant Recipients Using Two Definitions of Seroprotection

Lung transplant recipients are among those with the highest risk of influenza infection and complications each year. A few studies show adequate responses after influenza immunization; no studies examined the season-long protection. Influenza antibody concentrations were measured using hemagglutination inhibition assays before immunization, 2 to 4 weeks after immunization, and 6 months after immunization in 25 healthy controls and 54 lung transplant patients. Two definitions of seroprotection (40 hemagglutination units (HAU) and 160 HAU which confers about 95% protection) were used. Influenza vaccine responses were high in both groups postimmunization (100% at 40 HAU and 60% healthy and 61% lung transplant at 160 HAU; P = 1.0; chi-square). At 6 months after immunization, seroprotection rates at 40 HAU (95% healthy and 97% lung transplant; P = 1.0) and at 160 HAU (24% healthy and 36% lung transplant; P = 0.40) were observed. Seroprotection rates do not differ between healthy and transplant groups over 6 months when 40 HAU or 160 HAU is used. However, the seroprotection rates are disappointingly low when 160 HAU (the antibody concentration associated with 95% protection from infection) is used. Annual influenza vaccine should continue to be a high priority for lung transplant patients.

Immune influence of pregnancy on human H7N9 infection: a case report

IntroductionH7N9 infection has raised serious concerns worldwide. Pregnant women were considered to be at a high risk of influenza infection. Normal pregnancy was dependent on T helper (Th) 2 deviation. However, whether pregnancy influences the immune status of influenza H7N9 patients has not been reported. Case reportHere, we reported a case of pregnant woman in the first trimester with H7N9 infection compared with the two non-pregnant female H7N9 patients for clinical features and relevant immunological changes. We found that there were no differences in plasma levels of Th1 and Th2 cytokines between the pregnant and non-pregnant patients, and there was no Th2 deviation in the acute phase. However, the Th2 deviation was recurrent along with the clearance of infection in the H7N9 pregnant patient. ConclusionThese cases highlighted that the pregnant patient infected with H7N9 could induce an effective Th1 immune response equal to that of non-pregnant patients with H7N9 virus infection, although the pregnancy itself could lead to a Th2 deviation. These data suggested that pregnant patients could acquire a similar antiviral response for H7N9 infection versus non-pregnant patients.

Willingness of European healthcare workers to undergo vaccination against seasonal influenza: current situation and suggestions for improvement.

Uptake of vaccination against seasonal influenza in healthcare workers (HCWs) is, in general, low (vaccine coverage of 6–54%), as is awareness of its importance, and has been decreasing in most European Union (EU) countries in recent years. By virtue of their working environment, HCWs are at an increased risk of influenza infection and of subsequently transmitting the virus to vulnerable patients, in whom disease burden is significant. It could be argued that a similar or higher target vaccination rate to that recommended for older age groups and people with chronic medical conditions (75%) should be applied to HCWs, and the European Council recommends Member States to improve vaccination coverage in this population. In this context, better education of HCWs is needed to increase awareness and highlight the importance of HCW vaccination for the benefit of public health, particularly for their patients, who may be at risk of serious complications that could lead to disability or death. Secondary to these professional responsibilities, personal benefits (as well as benefits to close family and friends) should also be emphasised. Misconceptions that create barriers to vaccination need to be discussed openly and objections placed in the context of public health.