Frequency of Asthma Exacerbations and Upper Respiratory Tract Infections Among Adults With Asthma According to Vaccination Status: Does the annual influenza vaccine have a protective effect?

Objectives

Annual influenza vaccinations are recommended for asthma patients to prevent seasonal influenza and influenza-triggered asthma exacerbations. However, data on the beneficial effect of this vaccine on the frequency of asthma exacerbations are conflicting. Therefore, this study aimed to assess the effectiveness of the influenza vaccine in terms of reducing the frequency of asthma-related exacerbations and upper respiratory tract infections among adult patients with asthma.

Methods

This retrospective cohort study was performed from January to December 2018 in Muscat Governorate, Oman. A total of 466 patients attending 9 randomly selected primary health centres in Muscat Governorate were enrolled in the study and followed up for one year post vaccination.

Results

Most of the patients were female (70.6%) and had moderate persistent asthma (42.9%). There were 203 patients (43.6%) in the vaccinated group and 263 patients (56.4%) in the non-vaccinated group. A proportion of patients in each group had allergic rhinitis (28.6% and 25.5%, respectively). The frequency of upper respiratory tract infections over the one-year follow-up period was significantly lower in the vaccinated group than in the non-vaccinated group (37.9% versus 73%; relative risk [RR]: 2.299; 95% confidence interval [CI]: 1.834-2.882; P <0.001); however, there was no significant difference in terms of the frequency of asthma exacerbations (41.9% versus 45.2%; RR: 0.925; 95% CI: 0.750-1.141; P >0.050).

Conclusion

The influenza vaccine significantly reduces the frequency of upper respiratory tract infections over the following year. However, it does not significantly reduce the frequency of asthma exacerbations among Omani adults with asthma. Further studies are recommended to support the protective effect of the vaccine in this regard.

Early influenza vaccine effectiveness estimates using routinely collected data, Alberta, Canada, 2023/24 season

Timely and precise influenza vaccine effectiveness (VE) estimates are needed to guide public health messaging and impact vaccine uptake immediately. Using routinely collected laboratory, vaccination and health administrative data from Alberta, Canada, we estimated influenza VE against infection for the 2023/24 season on a near real-time basis, to late December, at 61% (95% CI: 58-64) against influenza A(H1N1), 49% (95% CI: 28-63) against influenza A(H3N2) and 75% (95% CI: 58-85) against influenza B.

Cardioprotective effects of Influenza Vaccination among Patients with Established Cardiovascular Disease or at High Cardiovascular Risk: A Systematic Review and Meta-analysis

BACKGROUND

The clinical impact of the influenza vaccination on cardiovascular outcomes in people with established cardiovascular disease (CVD) is still debated.

AIM

The aim of this meta-analysis was to estimate the effect of influenza vaccination on cardiovascular and cerebrovascular outcomes among patients with established CVD.

METHODS

We systematically searched all electronic databases from inception until 15 April 2022. Primary clinical outcomes were all-cause mortality (ACM), and major adverse clinical events (MACE). Secondary endpoints were heart failure, myocardial infarction, CV mortality, and stroke.

RESULTS

Eighteen articles (five randomized trials and thirteen observational studies), with a total of 22,532,165 patients were included in the analysis. There were 217,072 participants included in the high cardiovascular risk or established CVD population (vaccinated n = 111,073 and unvaccinated n = 105,999). The mean age of the patients was 68 years old, without any difference between groups (69 vs 71) years. At mean follow-up of 1.5 years, vaccinated group was associated with lower risk for all-cause mortality [HR, 0.71(95%CI, 0.63-0.80), p < 0.001], MACE [HR, 0.83(95%CI:0.72-0.96), p = 0.01], CV mortality [HR, 0.78(95%CI:0.68-0.90), p < 0.001] and myocardial infarction [HR, 0.82(95%CI:0.74-0.92), p < 0.001] compared to unvaccinated group. While incidence of stroke [HR, 1.03 (95%CI, 0.92-1.06), p = 0.61] and heart failure [HR, 0.74 (95%CI, 0.51-1.08), p = 0.12] did not differ between the two groups.

CONCLUSION

Influenza vaccination reduced major adverse clinical events, all-cause mortality, CV mortality and myocardial infarction. These highlighted the importance of influenza vaccination in established CVD or high cardiovascular risk.

Influenza Vaccination During COVID-19 in a Rural Community: A Cross-sectional Survey

Vaccination behavior is an informative metric for assessing flu seasons and is especially important to understand for the 2020–2021 flu season, which coincided with the COVID-19 pandemic. This study aimed to estimate flu vaccine behavior and assess vaccine perceptions during the pandemic season. Using a cross-sectional descriptive study design, we conducted an online survey to assess vaccination behavior and perceptions of both COVID-19 and the flu. Patients were identified as recently seen by providers in an academic internal medicine practice (n = 827) and surveys were distributed as messages in the Epic electronic medical record system. We found that 88.3% of respondents (188/206) had received their flu vaccination for the season at the time of their survey response in December 2020–February 2021. Of those that had not yet received the flu vaccine, only 13.6% indicated they planned on getting one. 12.5% of respondents said they had changed their flu vaccine plans due to the COVID-19 pandemic. Looking at differences from past season’s behavior, more individuals switched to getting the flu vaccine than those that switched to not getting the vaccine this season. The most frequently cited reasons for not receiving the flu vaccination were concerns about side effects and not being in a priority group. Changes in flu vaccination behavior from previous seasons represent a net positive in the direction of vaccine acceptance. Barriers to vaccination were identified and results from this study provide more information on vaccine perceptions, beliefs, and behavior, which can benefit future vaccination programs.

Flu Vaccination Coverage in 2020 in the Baixo Vouga Health Centre Group in Portugal

N/a.

Influenza Vaccination and Hospitalizations Among COVID-19 Infected Adults

INTRODUCTION

To date, there are no effective treatments for decreasing hospitalizations in Coronavirus disease 2019 (COVID-19) infections. It has been suggested that the influenza vaccine might attenuate the severity of COVID-19.

METHODS

This is a retrospective single-centered cohort review of a de-identified database of 2005 patients over the age of 18 within the University of Florida health care system who tested positive for COVID-19. Comorbidities and influenza vaccination status were examined. The primary outcome was severity of disease as reflected by hospitalization and intensive care unit (ICU) admission. Logistic regression was performed to examine the relationship between influenza status and hospitalization.

RESULTS

COVID-19-positive patients who had not received the influenza vaccination within the last year had a 2.44 (95% CI, 1.68, 3.61) greater odds of hospitalization and a 3.29 (95% CI, 1.18, 13.77) greater odds of ICU admission when compared with those who were vaccinated. These results were controlled to account for age, race, gender, hypertension, diabetes, chronic obstructive pulmonary disease, obesity, coronary artery disease, and congestive heart failure.

DISCUSSION

Our analysis suggests that the influenza vaccination is potentially protective of moderate and severe cases of COVID-19 infection. This protective effect holds regardless of comorbidity. The literature points to a potential mechanism via natural killer cell activation. Though our data potentially is limited by its generalizability and our vaccination rate is low, it holds significant relevance given the upcoming influenza season. Not only could simply encouraging influenza vaccination decrease morbidity and mortality from the flu, but it might help flatten the curve of the COVID-19 pandemic as well. We encourage further studies into this finding.

[Influenza Vaccination in Patients with Cardiovascular Disease Under 65 in the COVID-19 Era]

N/a.

Implementing an Influenza Vaccine Effectiveness Study in a Hospital Context in Portugal: The EVA Hospital Project

INTRODUCTION

The project 'Integrated Monitoring of Vaccines in Europe' aimed to measure seasonal influenza vaccine effectiveness against hospitalised adults, aged 65 years and over, with influenza. We describe the protocol implementation in Portugal.

MATERIAL AND METHODS

We implemented a test-negative design, targeting community-dwelling patients aged 65 years old and over hospitalised with severe acute respiratory illness. Patients were reverse transverse-polymerase chain reaction tested for influenza. Cases were those positive for influenza while others were controls. Most variables were collected using hospital medical records. Selection bias was evaluated by comparison with the laboratory influenza test requests database according to demographic characteristics. Crude, season-adjusted influenza vaccine effectiveness was estimated as = 1 - odds ratio, and 95% confidence intervals were obtained by conditional logistical regression, matched with the disease onset month.

RESULTS

The recruitment rate was 37.8%. Most participants (n = 368) were female (55.8%) and aged 80 years old and over (55.8%). This was similar to values for potentially eligible severe acute respiratory illness patients (80 years old and over: 56.8%, female: 56.2%). The proportion of missing values was below 2.5% for 20 variables and above 5% (maximum 11.6%) for six variables. Influenza vaccine effectiveness estimates were 62.1% against AH1pdm09 (95% confidence intervals: -28.1 to 88.8), 14.9% against A(H3N2) (95% confidence intervals: -69.6 to 57.3), 43.6% against B/Yam (95% confidence intervals: -66.2 to 80.8).

DISCUSSION

Given the non-existence of a coded admission database in either participating hospital the selection of severe acute respiratory illness due to clinical features was the feasible one. These results are only valid for the older adult population residing in the catchment area of the two participating hospitals who were admitted to a public hospital with severe influenza or SARI symptoms.

CONCLUSION

Despite the low participation rate, we observed comparable characteristics of participants and eligible severe acute respiratory illness patients. Data quality was high, and influenza vaccine effectiveness results were in accordance with the results of meta-analyses and European season-specific estimates. The final sample size was low, which inhibited obtaining estimates with good precision.

Reminder: Cardiovascular Patients Also Benefit from Influenza Vaccine

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Healthcare Students' Flu Vaccine Uptake in the Last 5 Years and Future Vaccination Acceptance: Is There a Possible Association?

Background: Despite the free-of-charge offer of influenza vaccines to at-risk subgroups, vaccine coverage remains low and far from the target, probably due to the false myths and misperceptions. We aimed to explore the healthcare students’ vaccination behavior and beliefs to find any association between vaccination uptake during the last 5 years and future vaccination acceptance.

Study design: A multicentre cross-sectional study.

Methods: From Oct 2017 to Nov 2018, the Italian healthcare students from 14 different universities in 2017/2018 were enrolled, through an online and anonymous questionnaire previously validated. Absolute and relative frequencies were calculated and Pearson's Chi-square test was used. A multinomial logistic regression model was performed. Results are expressed as relative Risk Ratio (RR) with 95% Confidence Intervals (95% CI). The level of significance chosen was P-value <0.05.

Results: A total of 3137 students were enrolled and 3131 questionnaires were analysed. 82.7% of the sample declared they had not received any flu vaccination during the last 5 years. Students who received flu vaccination 4 times or more during the last 5 years were more likely to do it again next year as well (95.1% vs 4.9%). The regression model showed that having received flu vaccination over the last 5 years was statistically associated with the intention of getting vaccinated during next season.

Conclusions: Frequency of flu vaccination is predictive for future acceptance among healthcare students. This association could have both implications for the organization of vaccination campaigns and improve educational strategies for this category of students.

Algorithm Formalization for Decision Making in Influenza Vaccination

Influenza is an important public health problem with consequences on the health of people, but also at the state level with social and health costs due to the morbidity and mortality produced. Vaccination is an act of care of high clinical complexity, which can be learned and trained, so that decision-making in vaccination requires elements of judgment that act logically in a cascade. The creation of algorithms and their implementation in computer systems will identify susceptible people more quickly and improve the competence in the administration of vaccines. For the creation of the algorithm, the variables and their relationships were identified through mathematical formulation. As a result, the nine variables for vaccination that result in 47 different clinical situations were identified (29 "non-vaccination" and 18 "vaccination" situations). The formalization of algorithms in vaccine administration allows to represent the process by which the professional carries out the decision making process.

Evaluation of Protective Immunity of Peptide Vaccines Composed of a 15-mer N-terminal Matrix Protein 2 and a Helper T-Cell Epitope Derived from Influenza A Virus

The matrix protein 2 of influenza A virus (IFAV) has a relatively conserved ectodomain (M2e) composed of 23 amino acids, and M2e-based vaccines have been suggested to induce broad protective immunity in mice. In this study, we investigated whether N-terminal sequence of M2e (nM2e)-based vaccines with more conserved nM2e could induce influenza viral neutralizing activity. We constructed linear peptide vaccines with an nM2e sequence for PR8 virus (nM2Pr) connected to a probable 17-mer IFAV-derived helper T-cell epitope (ThE: T1, T2, or T3) at its N- or C-terminus. The peptide vaccines induced significant production of nM2e Abs regardless of either type or location of the ThE-epitope in BALB/c mice, while only T3 was effective in C57BL/6 mice. The Abs against nM2Pr-T3 elicited broader binding affinities to the nM2e peptides derived from various IFAVs than those against T3-nM2Pr. In addition, the nM2e-based vaccines efficiently protected the immunized mice from the lethal challenge of PR8 virus. These results suggest that the more conserved nM2e without cysteine will be useful for development of universal peptide vaccines than M2e.

High-Dose Seasonal Influenza Vaccine in Patients Undergoing Dialysis

BACKGROUND AND OBJECTIVES

High-dose influenza vaccine, which contains fourfold more antigen than standard dose, is associated with fewer cases of influenza and less influenza-related morbidity in the elderly general population. Whether the high-dose influenza vaccine benefits patients on dialysis, whose immune response to vaccination is less robust than that of healthy patients, is uncertain.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We compared hospitalizations and deaths during the 2015-2016 and 2016-2017 influenza seasons by vaccine type (standard trivalent, standard quadrivalent, and high-dose trivalent influenza vaccine) administered within a national dialysis organization. The association of vaccine type with outcomes was estimated using Cox proportional hazards regression with adjustment for patient factors and "center effect." Analyses were stratified by age and dialysis modality.

RESULTS

Between September 1 and December 31, 2015, standard dose trivalent, standard dose quadrivalent, and high-dose trivalent influenza vaccines were administered to 3057 (31%), 5981 (61%), and 805 (8%) patients, respectively. The adjusted rates of first hospitalizations by vaccine type during the influenza season were 8.43, 7.88, and 7.99 per 100 patient-months, respectively, and the adjusted rates of death were 1.00, 0.97, and 1.04, respectively. These differences were not significant. In 2016, 3614 (39%) received quadrivalent vaccine, and 5700 (61%) received high-dose trivalent vaccine. The adjusted rates of first hospitalization by vaccine type were 8.71 and 8.04 per 100 patient-months, respectively, and the adjusted rates of death were 0.98 and 1.02, respectively. Receipt of high dose was associated with a significant reduction in hospitalization (hazard ratio, 0.93; 95% confidence interval, 0.86 to 1.00; P=0.04); there was no significant association with death. There was no significant heterogeneity of either association by age group or dialysis modality.

CONCLUSIONS

Receipt of high-dose compared with standard dose influenza vaccine in 2016-2017 was associated with lower rates of hospitalization in patients on dialysis, although that was not seen in 2015-2016.

[Impact of nosocomial transmission of influenza virus in an acute hospital]

OBJECTIVE

The increase in morbidity and mortality associated the influenza virus infections represents an important global challenge, with particular relevance within health institutions.The aim of the study was to highlight the impact, repercussions and characteristics of the nosocomial transmission of influenza virus.

METHODS

A sample of 286 hospitalized patients in a third-level hospital with confirmed influenza (virus RNA in respiratory specimens) is included. The study design was observational, through the collection of positive microbiological results from the 2016-2017 season. A comparative statistical analysis was carried out between cases of community-acquired influenza and hospital-acquired cases.

RESULTS

14.3% of the total sample (41 cases) was considered of nosocomial origin. Significant differences were observed in the percentage of vaccinated between hospital-acquired (34.1%) and community-acquired (50.2%); and in the number of days of hospitalization after diagnosis between both groups. The attack rate was 0.66%.

CONCLUSIONS

The nosocomial acquisition of the influenza virus resulted in a greater severity of the process and in the increase of days of hospital stay. Strict adherence to control measures and epidemiological surveillance of influenza cases has allowed to reduce the attack rate.

A Snapshot of Influenza Surveillance, Vaccine Recommendations, and Vaccine Access, Drivers, and Barriers in Selected Middle Eastern and North African Countries

Objectives

Influenza is a vaccine-preventable acute respiratory viral infection that causes epidemics annually around the globe. A regional influenza stakeholder network (MENA-ISN) comprised of experts assessed the status of influenza prevention and control using a structured survey.

Methods

A survey questionnaire was used to obtain information from each participating country on surveillance system, the burden of disease, influenza vaccination programs, recommendations, funding and access for vaccine and vaccination, target rate, coverage rate monitoring, and drivers and barriers to influenza vaccination.

Results

Out of the 10 countries that participated, nine had an influenza surveillance system and vaccination policy, and seven had World Health Organization (WHO) accredited reference laboratory. Three countries had burden of disease data available and eight had a reimbursement vaccine policy. Influenza vaccine was available in five countries through the Ministry of Health whereas in others, pharmacies also dispensed for the private sector. In all countries, prescribers were physicians, and vaccinators, which could be physicians, nurses, and pharmacists. Eight countries had a set vaccination target rate and only three monitored the influenza coverage rates. Drivers and barriers of vaccination were similar in all countries.

Conclusions

Despite existing policies, influenza vaccination coverage remains far below the WHO recommendations. Increased awareness and effective implementation of policies with collaboration of stakeholders can help increase the rates to reach WHO targets.

Narcolepsy with cataplexy and hyperthyroidism sudden appeared after H1N1 vaccination

Narcolepsy type 1 (NT1) is a chronic sleep disorder, characterized by excessive daytime sleepiness, cataplexy and fragmented nocturnal sleep. It is caused by a hypocretin deficiency due to a significant reduction of the neurons producing it. In the last years, it has been postulated that an autoimmune mechanism would be responsible for the destruction of these neurons in those genetically predisposed patients. The increased incidence of narcolepsy after the pandemic H1N1 influenza vaccination campaign in 2009-2010 is known. We present below the case of an adult patient who, 10 days after receiving H1N1 vaccination, suffers a traffic accident after falling asleep. Subsequent studies revealed hyperthyroidism due to Graves disease. In spite of the treatment, the patient persisted with daily and disabling daytime sleepiness, sleep attacks and episodes of generalized muscle atony with preservation of consciousness. A nocturnal polysomnography and multiple sleep latency test (MSLT) were performed with a diagnosis of NT1. The particularity of this case is the presentation of 2 autoimmune diseases triggered by an H1N1 vaccine without adjuvant, so far there is only evidence of NT1 associated with vaccines with adjuvant and viral infection. The association of both entities has made us reflect on the autoimmune mechanism, reinforcing the theory of its role in the onset of the disease.

Mouse Models of Influenza Infection with Circulating Strains to Test Seasonal Vaccine Efficacy

Influenza virus infection is a significant cause of morbidity and mortality worldwide. The surface antigens of influenza virus change over time blunting both naturally acquired and vaccine induced adaptive immune protection. Viral antigenic drift is a major contributing factor to both the spread and disease burden of influenza. The aim of this study was to develop better infection models using clinically relevant, influenza strains to test vaccine induced protection. CB6F1 mice were infected with a range of influenza viruses and disease, inflammation, cell influx, and viral load were characterized after infection. Infection with circulating H1N1 and representative influenza B viruses induced a dose-dependent disease response; however, a recent seasonal H3N2 virus did not cause any disease in mice, even at high titers. Viral infection led to recoverable virus, detectable both by plaque assay and RNA quantification after infection, and increased upper airway inflammation on day 7 after infection comprised largely of CD8 T cells. Having established seasonal infection models, mice were immunized with seasonal inactivated vaccine and responses were compared to matched and mismatched challenge strains. While the H1N1 subtype strain recommended for vaccine use has remained constant in the seven seasons between 2010 and 2016, the circulating strain of H1N1 influenza (2009 pandemic subtype) has drifted both genetically and antigenically since 2009. To investigate the effect of this observed drift on vaccine induced protection, mice were immunized with antigens from A/California/7/2009 (H1N1) and challenged with H1N1 subtype viruses recovered from 2009, 2010, or 2015. Vaccination with A/California/7/2009 antigens protected against infection with either the 2009 or 2010 strains, but was less effective against the 2015 strain. This observed reduction in protection suggests that mouse models of influenza virus vaccination and infection can be used as an additional tool to predict vaccine efficacy against drift strains.

A Survey of Parental Perception and Pattern of Action in Response to Influenza-like Illness in Their Children: Including Healthcare Use and Vaccination in Korea

Seasonal influenza is a significant cause of morbidity and mortality of children in Korea. However, few data are available on parental perception and action toward childhood influenza. This study aimed to characterize parental perception and patterns of action in response to influenza and influenza-like illnesses (ILIs), including vaccination and healthcare use. This prospective study involved a random survey of parents whose children were aged 6-59 months. The survey was conducted in October 2014. The study included 638 parents of 824 children younger than 6 years. Most parental information of influenza came from mass media (28.2%) and social media (15.5%). The factor that most often motivated parents to vaccinate their children against influenza was promotion of the government or mass media (36.6%). Negative predictors of immunization included safety concerns about influenza vaccination (28.1%) and mistrust in the vaccine's effectiveness (23.3%). Therefore, correct information about influenza and vaccination from mass media will be one of the cornerstones for implementing a successful childhood immunization program and reducing morbidity and mortality in Korea. Furthermore, to enroll younger children in vaccination programs, and to minimize coverage gaps, public concerns about vaccine safety should be resolved. The demographic data in the present study will be used to provide a deeper insight into a parental perception and will help health care providers increase influenza immunization rate.

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

BACKGROUND

In 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.

METHODS

Observational 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.

RESULTS

40.5% 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%).

CONCLUSION

Pregnant 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.

Perception and Attitudes of Korean Obstetricians about Maternal Influenza Vaccination

Pregnant women are prioritized to receive influenza vaccination. However, the maternal influenza vaccination rate has been low in Korea. To identify potential barriers for the vaccination of pregnant women against influenza, a survey using a questionnaire on the perceptions and attitudes about maternal influenza vaccination was applied to Korean obstetricians between May and August of 2014. A total of 473 respondents participated in the survey. Most respondents (94.8%, 442/466) recognized that influenza vaccination was required for pregnant women. In addition, 92.8% (410/442) respondents knew that the incidence of adverse events following influenza vaccination is not different between pregnant and non-pregnant women. However, 26.5% (124/468) obstetricians strongly recommended influenza vaccination to pregnant women. The concern about adverse events following influenza vaccination was considered as a major barrier for the promotion of maternal influenza vaccination by healthcare providers. Providing professional information and education about maternal influenza vaccination will enhance the perception of obstetricians about influenza vaccination to pregnant women and will be helpful to improve maternal influenza vaccination coverage in Korea.

Association between Living Arrangements and Influenza Vaccination Rates among Elderly South Korean People: The Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-2)

BACKGROUND

This study aimed to investigate the association between living arrangements and influenza vaccination among elderly South Korean subjects.

METHODS

We used data from the fifth Korean National Health and Nutrition Examination Survey. Participants older than 65 years were included and categorized into 4 groups according to the type of living arrangement as follows: (1) living alone group; (2) living with a spouse group; (3) living with offspring (without spouse) group; and (4) living with other family members group. A total of 1,435 participants were included in this cross-sectional analysis.

RESULTS

A lower vaccination rate was observed in the living with offspring (without spouse) group, whereas the living with a spouse group had higher rates of both seasonal and H1N1 influenza vaccination. After adjusting for age, sex, region, education level, income level, and number of comorbidities, the living with offspring (without spouse) group had a higher H1N1 vaccination non-receipt rate than the living alone group (odds ratio, 2.03; 95% confidence interval, 1.08-3.82).

CONCLUSION

Influenza vaccination rates differed according to the type of living arrangement. Particularly, those living with offspring (without spouse) had the lowest H1N1 influenza vaccination rate compared to those with other living arrangements, and this difference was significant. Interventions to improve influenza vaccination coverage should target not only elderly persons who live alone, but also those living with offspring.

Influenza vaccination and associated factors among Korean cancer survivors : a cross-sectional analysis of the Fourth & Fifth Korea National Health and Nutrition Examination Surveys

Influenza vaccination is important for cancer survivors, a population with impaired immunity. This study was designed to assess influenza vaccination patterns among Korean cancer survivors. In this cross-sectional analysis, data were obtained from standardized questionnaires from 943 cancer survivors and 41,233 non-cancer survivors who participated in the Fourth and Fifth Korea National Health and Nutrition Examination Surveys (2007-2011). We identified the adjusted influenza vaccination rates and assessed factors associated with influenza vaccination using multivariate logistic regression. Cancer survivors tended to have a higher adjusted influenza vaccination rate than the general population. The rates for influenza vaccination in specific cancer types such as stomach, hepatic, colon, and lung cancers were significantly higher than non-cancer survivors. Among all cancer survivors, those with chronic diseases, elderly subjects, and rural dwellers were more likely to receive influenza vaccination; those with cervical cancer were less likely to receive influenza vaccination. Cancer survivors were more likely to receive influenza vaccinations than non-cancer survivors, but this was not true for particular groups, especially younger cancer survivors. Cancer survivors represent a sharply growing population; therefore, immunization against influenza among cancer survivors should be concerned as their significant preventative healthcare services.

Construction of recombinant bacmid containing m2e-ctxb and producing the fusion protein in insect cell lines

BACKGROUND

Sequence variations in glycoproteins of influenza virus surface impel us to design new candidate vaccines yearly. Ectodomain of influenza M2 protein is a surface and highly conserved protein. M2e in influenza vaccines may eliminate the need for changing vaccine formulation every year.

OBJECTIVES

In this study, a recombinant baculovirus containing M2e and cholera toxin subunit B fusion gene was generated with transposition process to express in large amounts in insect cell lines.

MATERIALS AND METHODS

M2e-ctxB fusion gene was created and cloned into pFastBac HT. The recombinant vector was transformed into DH10Bac cells to introduce the fusion gene into the bacmid DNA via a site-specific transposition process. The recombinant bacmid was then extracted from white colonies and further analyzed using PCR, DNA sequence analyzing, and indirect immunofluorescence assay.

RESULTS

PCR and DNA sequence analyzing results showed that the fusion gene was constructed as a single open reading frame and was successfully inserted into bacmid DNA. Moreover, indirect immunofluorescence results showed that the fusion gene was successfully expressed.

CONCLUSIONS

Baculovirus expression vector system is valuable to produce M2e based influenza vaccines due to its simple utilization and ease of target gene manipulation. The expressed protein in such systems can improve the evaluating process of new vaccination strategies.

Parents' vaccine beliefs: a study of experiences and attitudes among parents of children in private pre-schools

Even among highly vaccinated populations such as Rhode Island (RI), there exists a vulnerability to disease outbreaks. This is the basis for requiring proof of immunization for enrollment into school. Although RI grants medical, temporary, and religious vaccination exemptions, little is known about the beliefs of RI parents who seek exemptions for their children. The purpose of this small-scale, cross-sectional, Web-based survey is to describe the vaccine behaviors and beliefs of parents of children attending private pre-school in Providence, RI. In spite of limitations, the results provided the intended baseline assessment of the target population. While such findings should be interpreted with caution, they can be used as the foundation for future research and interventions.

Influenza vaccination in patients with diabetes: disparities in prevalence between African Americans and Whites

Background

Patients with diabetes who contract influenza are at higher risk of complications, such as hospitalization and death. Patients with diabetes are three times more likely to die from influenza complications than those without diabetes. Racial disparities among patients with diabetes in preventive health services have not been extensively studied.

Objective

To compare influenza vaccination rates among African Americans and Whites patients with diabetes and investigate factors that might have an impact on racial disparities in the receipt of influenza vaccinations.

Methods

A secondary data analysis of 47,283 (unweighted) patients with diabetes from the 2011 Behavioral Risk Factor Surveillance System survey (BRFSS) (15,902,478 weighted) was performed. The survey respondents were asked whether they received an influenza vaccination in the last twelve months. We used logistic regression to estimate the odds of receiving the influenza vaccine based on race.

Results

The results indicated a significantly lower proportion of African Americans respondents (50%) reported receiving the influenza vaccination in the last year when compared with Whites respondents (61%). Age, gender, education, health care coverage, health care cost, and employment status were found to significantly modify the effect of race on receiving the influenza vaccination.

Conclusions

This study found a significant racial disparity in influenza vaccination rates in adults with diabetes with higher rates in Whites compared to African Americans individuals. The public health policies that target diabetes patients in general and specifically African Americans in the 65+ age group, women, and homemakers, may be necessary to diminish the racial disparity in influenza vaccination rates between African Americans and Whites diabetics.

Influenza vaccines: unmet needs and recent developments

Influenza is a worldwide public health concern. Since the introduction of trivalent influenza vaccine in 1978, vaccination has been the primary means of prevention and control of influenza. Current influenza vaccines have moderate efficacy, good safety, and acceptable tolerability; however, they have unsatisfactory efficacy in older adults, are dependent on egg supply for production, and are time-consuming to manufacture. This review outlines the unmet medical needs of current influenza vaccines. Recent developments in influenza vaccines are also described.

Overview of Influenza Vaccines in Children

Prevention of influenza infection through vaccination is the best strategy to reduce its disease burden; however, annual revaccination is required to provide protection from circulating virus strains. Currently available influenza vaccines are trivalent inactivated influenza vaccines (IIV) or live-attenuated influenza vaccines (LAIV); however, quadrivalent formulations of IIV and LAIV are expected to be available for the 2013-2014 influenza season. Among children 6 months through 8 years of age receiving their first influenza vaccination, 2 doses of vaccines are required to provide adequate protection. Because of the wide range of circulating influenza viruses and host immune responses, estimates of vaccine effectiveness vary widely by year, age group, and vaccine studied. We summarize the evidence base for pediatric influenza vaccination, and we describe the challenges and limitations of protecting this population with currently available vaccines.

Influenza Virus-like Particle Containing Two Different Subtypes of Hemagglutinin Confers Protection in Mice Against Lethal Challenge With A/PR8 (H1N1) and A/HK (H3N2) Viruses

BACKGROUND

Preventing the seasonal or pandemic outbreak of influenza can be powerful and cost-effective.

OBJECTIVES

In this study, we constructed a novel virus-like particle (VLP) platform that contains two hemagglutinin (HA) subtypes and evaluated immunogenicity of constructed VLP in mice.

MATERIALS AND METHODS

This recombinant candidate vaccine model resulted in the expression of two HAs of H1N1 and H3N2 subtypes co-localized within a VLP. Following infection of insect cells with recombinant baculovirus co-expressing H1, H3 and M1 proteins, VLPs with size of 80-120 nm were self-assembled, budding, and released into the insect culture medium. The resulting VLPs which contained two different subtypes of hemagglutinin were purified by ultracentrifugation. The immunogenicity of VLPs was evaluated in mice following immunization.

RESULTS

Our data showed that vaccination using VLPs elicited robust levels of serum IgG, and viral neutralizing antibodies against A/PR8 (H1N1) and A/HK (H3N2) viruses. Following challenge with lethal dose of A/PR8 (H1N1) and A/HK (H3N2, vaccinated mice were protected, displaying no sign of weight loss and mortality compared to non-vaccinated control mice.

CONCLUSIONS

VLPs can serve as a promising vaccination strategy to control influenza virus.

Safety and immunogenicity of a new trivalent inactivated split-virus influenza vaccine in healthy Korean children: a randomized, double-blinded, active-controlled, phase III study

We report results of a randomized, double-blinded, active-controlled, phase III study conducted to evaluate the immunogenicity and safety of a new trivalent inactivated split-virus influenza vaccine (GC501) manufactured by the Green Cross Corporation in Korea. A total of 283 healthy children aged 6 months to < 18 yr were randomized to receive either GC501 or control. Of the GC501 recipients, seroconversion occurred in 48.5% for A/H1N1, 67.7% for A/H3N2 and 52% for influenza B. The proportion of subjects who had post-vaccination hemagglutination-inhibition titers of 1:40 or greater was 90.7% for A/H1N1, 86.8% for A/H3N2 and 82.4% for influenza B in the GC501 recipients. No serious adverse events related to vaccination, or withdrawals because of adverse events were reported. The majority of solicited adverse events were mild in intensity. GC501 vaccine has good tolerability and favorable immunogenicity in children aged 6 months to < 18 yr. The addition of one more brand of influenza vaccine may allow for better global accessibility of vaccine for epidemics or future pandemics.

Immunogenicity and safety of trivalent inactivated influenza vaccine: a randomized, double-blind, multi-center, phase 3 clinical trial in a vaccine-limited country

Influenza vaccines are the primary method for controlling influenza and its complications. This study was conducted as a phase 3, randomized, double-blind, controlled, multi-center trial at seven university hospitals to evaluate the immunogenicity and safety of an inactivated, split, trivalent influenza vaccine (GC501, Green Cross Corporation, Yongin, Korea), which was newly manufactured in Korea in 2008. Between September 21 and 26, a total of 329 healthy subjects were recruited for the immunogenicity analysis, while 976 subjects were enrolled for the safety analysis. The GC501 vaccine met both FDA and EMEA criteria with ≥ 80% of subjects achieving post-vaccination titers ≥ 40 for all three subtypes, even in the elderly. The vaccine was well tolerated with only mild systemic and local adverse events. In summary, GC501 showed excellent immunogenicity and a good safety profile in both young adults and the elderly. The licensure of GC501 might be an important basis in preparation for the future influenza pandemic.