Flu vaccination in the elderly

Seasonal flu is a very serious public health problem in the elderly due to its morbidity and mortality and financial and social costs arising from this. The aim of this review is to describe the magnitude and importance of seasonal flu in this population group, and its prevention by means of vaccination. For this reason, an updated account of the composition of the vaccine, its dosage and administration route, vaccine safety and the evaluation of the immunogenicity and effectiveness of vaccination. There is variation between different countries and official organisations on the age at which flu vaccination must be established in the elderly. New flu vaccination strategies need to be introduced, to further improve flu vaccination cover in Spain.     

Healthy Bodies,Toxic Medicines: College Students and the Rhetorics of Flu Vaccination

This article examines flu vaccination beliefs and practices produced during a survey of undergraduate students in Spring 2012 (IRB#10-732). This research uses the methods of rhetorical analysis — or the study of persuasive features and arguments used in language — to examine statements respondents made regarding flu and flu vaccine. In these responses, students generated unique categories of arguments about the perceived dangers of flu vaccination, including the assertion that vaccines cause disease (including illnesses and conditions other than flu), that vaccines are toxic medicines, and that vaccines carry unknown, population-wide risks that are inadequately acknowledged. This study provides insight into vaccination beliefs and rationales among a population at risk of flu (college students) and suggests that further study of this population may yield important keys to addressing flu vaccine concerns as expressed by college students. Rhetorical analysis also offers a useful set of methods to understanding vaccination beliefs and practices, adding to existing methods of study and analysis of vaccination practices and beliefs in medicine and public health.     

Comparative evaluation of the reactogenicity and immunogenicity of inactivated influenza vaccines in the elderly

A comparative study was carried out to assess reactogenicity and immunogenicity of inactivated influenza vaccines (Begrivac, Vaxigrip, Grippol, Influvac, and Fluarix), licensed in Russia. Immunization of the elderly demonstrated low reactogenicity and high immunogenicity for all vaccines. Concomitant chronic diseases had no influence on the vaccine immunogenicity levels, which testifies to the benefit of vaccination in this age group. In the group of vaccinated the highest seroconversion to all vaccine strains was found for Vaxigrip (82-89% for group A viruses and 86% for group B virus); the vaccine demonstrated the highest level of diagnostic increase of antibody titers to all 3 viruses, i.e. 69.0% (p < .05), with 22.0% of vaccinees gained antibodies to 2 vaccine viruses (91.0% in total). The number of positive responses to 3 and 2 strains in subjects immunized with Fluarix, Begrivac and Influvac reached 85.0%, 85.0% and 83.0% respectively. It is noteworthy that the combination of surface antigens of A and B flu viruses in low concentration with polyoxidonium immune modulator in Grippol induced intensive immune response.     

Efectividad de la vacuna antigripal en la prevención de la gripe en personas mayores de 65 años

IntroductionInfluenza is one of the diseases with the greatest epidemiological impact and of maximum relevance in the management of health services. The flu vaccine can have great variability each season, so our objective was to find out the effectiveness of the flu vaccine for the 2017/2018 season for the prevention of severe cases of flu in people over 65 years of age in a 385-bed acute general hospital.Material and methodStudy of cases and controls. All hospitalized patients with laboratory-confirmed influenza older than 65 years during the 2017/2018 season were included. Those who met the criteria for a severe case of influenza were considered cases. Those who did not meet the severity criteria were considered controls. Factors associated with the development of severe influenza were calculated.ResultsThe median age was 68 years (SD 91.87). The attack rate was 0.23 per hundred inhabitants and the vaccine effectiveness was 38%. The vaccinated and unvaccinated groups were different in terms of age (p < 0.0481). Vaccination status against severe influenza was found to be an independent protective factor (OR = 0.840; 0.746-0.913).ConclusionsThe effectiveness of influenza vaccination provided greater protection against infection and reduced the severity of influenza in older hospitalized patients. These findings should be taken into account to improve vaccination strategies and achieve better vaccination coverage in the population at risk.     

Public communication, risk perception, and the viability of preventive vaccination against communicable diseases

Because of the nature of preventive vaccination programs, the viability of these public health interventions is particularly susceptible to public perceptions. This is because vaccination relies on a concept of 'herd immunity', achievement of which requires rational public behavior that can only be obtained through full and accurate communication about risks and benefits. This paper describes how irrational behavior that threatens the effectiveness of vaccination programs--both in crisis and non-crisis situations--can be tied to public perceptions created by media portrayals of health risks. I concentrate on childhood vaccination as an exemplar of 'non-crisis' preventive vaccination, and on the recent flu vaccine shortage as a 'crisis' situation. The paper concludes with an examination of the steps necessary to resolve these threats through better public communication.     

Addition of the immunostimulatory oligonucleotide IMT504 to a seasonal flu vaccine increases hemagglutinin antibody titers in young adult and elder rats, and expands the anti-hemagglutinin antibody repertoire

Flu vaccines are partially protective in infants and elder people. New adjuvants such as immunostimulatory oligonucleotides (ODNs) are strong candidates to solve this problem, because a combination with several antigens has demonstrated effectiveness. Here, we report that IMT504, the prototype of a major class of immunostimulatory ODNs, is a potent adjuvant of the influenza vaccine in young adult and elderly rats. Flu vaccines that use virosomes or whole viral particles as antigens were combined with IMT504 and injected in rats. Young adult and elderly animals vaccinated with IMT504-adjuvated preparations reached antibody titers 20-fold and 15-fold higher than controls, respectively. Antibody titers remained high throughout a 120 day-period. Animals injected with the IMT504-adjuvated vaccine showed expansion of the anti-hemagglutinin antibody repertoire and a significant increase in the antibody titer with hemagglutination inhibition capacity when confronted to viral strains included or not in the vaccine. This indicates that the addition of IMT504 in flu vaccines may contribute to the development of significant cross-protective immune response against shifted or drifted flu strains.     

Influenza vaccination in the elderly: 1. Determinants of acceptance.

In the autumn of 1982 routine annual influenza vaccination was offered, by reminder letters and follow-up telephone calls, to 273 independent elderly individuals registered at a community health clinic in Hamilton, Ont. The demographic and geographic characteristics and the health beliefs of those who either accepted or did not accept the vaccine were compared. Among those who received reminder letters there were no significant differences in the rates of vaccine acceptance according to age, sex, household composition or ease of access to the clinic. The patients who reported having previously experienced side effects from the vaccine and perceived a lack of efficacy of the vaccine were more likely not to accept it this time. Both a lack of effort by health care providers (to promote vaccination) and patient behaviour appeared to contribute to pre-existing low levels of influenza vaccination coverage. Although physicians'' efforts to inform patients about the vaccination clinics resulted in a tripling of the overall rate of acceptance of the vaccine, there remained a "hard core" of almost half the patients who were unwilling to receive the vaccine, apparently because they perceived its risks to outweigh its benefits.     

Determinants of non-vaccination against pandemic 2009 H1N1 influenza in pregnant women: a prospective cohort study

Background

In October 2009, the French government organized a national-wide, free of charge vaccination campaign against pandemic H1N1 influenza virus, especially targeting pregnant women, a high risk group for severe illness. The study objective was to evaluate pandemic flu vaccine uptake and factors associated with non-vaccination in a population of pregnant women.

Methodology/Principal Findings

In a prospective cohort conducted in 3 maternity hospitals in Paris, 882 pregnant women were randomly included between October 12, 2009 and February 3, 2010, with the aim to study characteristics of pandemic influenza during pregnancy. At inclusion, socio-demographic, medical, obstetrical factors and those associated with a higher risk of flu exposition and disease-spreading were systematically collected. Pandemic flu vaccine uptake was checked until delivery. 555 (62.9%) women did not get vaccinated. Determinants associated with non-vaccination in a multivariate logistic regression were: geographic origin (Sub-Saharan African origin, adjusted Odd Ratio aOR = 5.4[2.3–12.7], North African origin, aOR = 2.5[1.3–4.7] and Asian origin, aOR = 2.1[1.7–2.6] compared to French and European origin) and socio-professional categories (farmers, craftsmen and tradesmen, aOR = 2.3[2.0–2.6], intermediate professionals, aOR = 1.3[1.0–1.6], employees and manual workers, aOR = 2.5[1.4–4.4] compared to managers and intellectual professionals). The probability of not receiving pandemic flu vaccine was lower among women vaccinated against seasonal flu in the previous 5 years (aOR = 0.6[0.4–0.8]) and among those who stopped smoking before or early during pregnancy (aOR = 0.6[0.4–0.8]). Number of children less than 18 years old living at home, work in contact with children or in healthcare area, or professional contact with the public, were not associated with a higher vaccine uptake.

Conclusions/Significance

In this cohort of pregnant women, vaccine coverage against pandemic 2009 A/H1N1 flu was low, particularly in immigrant women and those having a low socio-economic status. To improve its effectiveness, future vaccination campaign for pregnant women should be more specifically tailored for these populations.     

Vaccination of the elderly: an update

Vaccination of the elderly still requires attention. The vaccination coverage for tetanus, influenza and pneumococcal infections is merely 40, 60 and 30%, respectively. Besides a reduction in mortality (67%) and a reduction of hospitalisation for pneumonia and influenza (50%), vaccination against influenza also results in a decrease in cardio- and cerebrovascular morbidity (20%) as well as in a decrease in the frequency of doctor visits for respiratory infections for COPD patients. Vaccination of children and health care personnel can further reduce transmission of influenza and subsequent influenza related complications in the elderly. Pneumococcal invasive disease can be reduced by 50% through vaccination. Vaccination of children with the conjugate vaccine can further reduce the incidence of pneumococcal invasive disease in the elderly. Further improvements in vaccine coverage levels are needed, mainly among elderly persons, children and persons at increased risk.     

Determinants of refusal of A/H1N1 pandemic vaccination in a high risk population: a qualitative approach

Background

Our study analyses the main determinants of refusal or acceptance of the 2009 A/H1N1 vaccine in patients with cystic fibrosis, a high-risk population for severe flu infection, usually very compliant for seasonal flu vaccine.

Methodology/Principal Findings

We conducted a qualitative study based on semi-structured interviews in 3 cystic fibrosis referral centres in Paris, France. The study included 42 patients with cystic fibrosis: 24 who refused the vaccine and 18 who were vaccinated. The two groups differed quite substantially in their perceptions of vaccine- and disease-related risks. Those who refused the vaccine were motivated mainly by the fears it aroused and did not explicitly consider the 2009 A/H1N1 flu a potentially severe disease. People who were vaccinated explained their choice, first and foremost, as intended to prevent the flu''s potential consequences on respiratory cystic fibrosis disease. Moreover, they considered vaccination to be an indirect collective prevention tool. Patients who refused the vaccine mentioned multiple, contradictory information sources and did not appear to consider the recommendation of their local health care provider as predominant. On the contrary, those who were vaccinated stated that they had based their decision solely on the clear and unequivocal advice of their health care provider.

Conclusions/Significance

These results of our survey led us to formulate three main recommendations for improving adhesion to new pandemic vaccines. (1) it appears necessary to reinforce patient education about the disease and its specific risks, but also general population information about community immunity. (2) it is essential to disseminate a clear and effective message about the safety of novel vaccines. (3) this message should be conveyed by local health care providers, who should be involved in implementing immunization.     

Vaccinating Sons against HPV: Results from a U.S. National Survey of Parents

Purpose

The quadrivalent HPV vaccination was approved for use in males ages 9 to 26 in 2009 and recommended for routine administration in 2011. The purpose of this study was to uncover predictable commonalities amongst parents who chose to vaccinate their 11–17 year old sons against HPV.

Methods

We compiled data from a U.S. national sample of 779 parents with sons 11–17 years old using a web-based survey to gather information about behavioral and sociodemographic factors which predicted receipt of 1 or more HPV vaccine doses based on parental report. Predictors were first modeled individually for univariable associations. Significant predictors (p<0.10) were combined in a multivariable model.

Results

In the adjusted model, independent predictors included receipt of flu vaccination, health insurance coverage and sexual health topic discussions with sons. Sons who had received a flu shot in the last two years more frequently received at least one dose of the vaccine (OR 1.82; 95% CI 1.45–2.26). Sons covered by private health insurance had decreased odds of HPV vaccination (OR 0.56 95% CI 0.37–0.83). Lastly, parents who had discussed sexual health topics with their sons were more likely to vaccinate (OR 1.61; 95% CI 1.37–1.89).

Conclusions

Male vaccination rates in the U.S. have increased, but males continue to be under-immunized. Utilization of health care is an important factor in HPV vaccine uptake; therefore, health care providers should use every contact as an opportunity to vaccinate. Communication about sexual health topics may provide a forum for parents and health care providers to have conversations about HPV vaccination as those more comfortable discussing these topics may also be more comfortable discussing HPV vaccination.     

Factors Associated with Influenza Vaccination of Hospitalized Elderly Patients in Spain

Vaccination of the elderly is an important factor in limiting the impact of influenza in the community. The aim of this study was to investigate the factors associated with influenza vaccination coverage in hospitalized patients aged ≥65 years hospitalized due to causes unrelated to influenza in Spain. We carried out a cross-sectional study. Bivariate analysis was performed comparing vaccinated and unvaccinated patients, taking in to account sociodemographic variables and medical risk conditions. Multivariate analysis was performed using multilevel regression models. We included 1038 patients: 602 (58%) had received the influenza vaccine in the 2013–14 season. Three or more general practitioner visits (OR = 1.61; 95% CI 1.19–2.18); influenza vaccination in any of the 3 previous seasons (OR = 13.57; 95% CI 9.45–19.48); and 23-valent pneumococcal polysaccharide vaccination (OR = 1.97; 95% CI 1.38–2.80) were associated with receiving the influenza vaccine. Vaccination coverage of hospitalized elderly people is low in Spain and some predisposing characteristics influence vaccination coverage. Healthcare workers should take these characteristics into account and be encouraged to proactively propose influenza vaccination to all patients aged ≥65 years.     

Age affects quantity but not quality of antibody responses after vaccination with an inactivated flavivirus vaccine against tick-borne encephalitis

The impairment of immune functions in the elderly (immunosenescence) results in post-vaccination antibody titers that are significantly lower than in young individuals. It is, however, a controversial question whether also the quality of antibodies declines with age. In this study, we have therefore investigated the age-dependence of functional characteristics of antibody responses induced by vaccination with an inactivated flavivirus vaccine against tick-borne encephalitis (TBE). For this purpose, we quantified TBE virus-specific IgG and neutralizing antibody titers in post-vaccination sera from groups of young and elderly healthy adults and determined antibody avidities and NT/ELISA titer ratios (functional activity). In contrast to the quantitative impairment of antibody production in the elderly, we found no age-related differences in the avidity and functional activity of antibodies induced by vaccination, which also appeared to be independent of the age at primary immunization. There was no correlation between antibody avidity and NT/ELISA ratios suggesting that additional factors affect the quality of polyclonal responses, independent of age. Our work indicates that healthy elderly people are able to produce antibodies in response to vaccination with similar avidity and functional activity as young individuals, albeit at lower titers.     

Vaccine and adjuvant design for emerging viruses: mutations, deletions, segments and signaling

Vaccination is currently the most effective strategy to medically control viral diseases. However, developing vaccines is a long and expensive process, and traditional methods, such as attenuating wild-type viruses by serial passage, may not be suitable for all viruses and may lead to vaccine safety considerations, particularly in the case of the vaccination of particular patient groups, such as the immunocompromised and the elderly. In particular, developing vaccines against emerging viral pathogens adds a further level of complexity, as they may only be administered to small groups of people or only in response to a specific event or threat, limiting our ability to study and evaluate responses. In this commentary, we discuss how novel techniques may be used to engineer a new generation of vaccine candidates as we move toward a more targeted vaccine design strategy, driven by our understanding of the mechanisms of viral pathogenesis, attenuation and the signaling events which are required to develop a lasting, protective immunity. We will also briefly discuss the potential future role of vaccine adjuvants, which could be used to bridge the gap between vaccine safety, and lasting immunity from a single vaccination.     

Low Rate of Pandemic A/H1N1 2009 Influenza Infection and Lack of Severe Complication of Vaccination in Pregnant Women: A Prospective Cohort Study

Background

In 2009, pregnant women were specifically targeted by a national vaccination campaign against pandemic A/H1N1 influenza virus. The objectives of the COFLUPREG study, initially set up to assess the incidence of serious forms of A/H1N1 influenza, were to assess the consequences of maternal vaccination on pregnancy outcomes and maternal seroprotection at delivery.

Methods

Pregnant women, between 12 and 35 weeks of gestation, non vaccinated against A/H1N1 2009 influenza were randomly selected to be included in a prospective cohort study conducted in three maternity centers in Paris (France) during pandemic period. Blood samples were planned to assess hemagglutination inhibition (HI) antibody against A/H1N1 2009 influenza at inclusion and at delivery.

Results

Among the 877 pregnant women included in the study, 678 (77.3%) had serum samples both at inclusion and delivery, and 320 (36.5%) received pandemic A/H1N1 2009 influenza vaccine with a median interval between vaccination and delivery of 92 days (95% CI 48–134). At delivery, the proportion of women with seroprotection (HI antibodies titers against A/H1N1 2009 influenza of 1∶40 or greater) was 69.9% in vaccinated women. Of the 422 non-vaccinated women with serological data, 11 (2.6%; 95%CI: 1.3–4.6) had laboratory documented A/H1N1 2009 influenza (1 with positive PCR and 10 with serological seroconversion). None of the 877 study’s women was hospitalized for flu. No difference on pregnancy outcomes was evidenced between vaccinated women, non-vaccinated women without seroconversion and non-vaccinated women with flu.

Conclusion

Despite low vaccine coverage, incidence of pandemic flu was low in this cohort of pregnant women.No effect on pregnancy and delivery outcomes was evidenced after vaccination.     

The importance of the age factor in cancer vaccination at older age

Cancer is an age-related disease, and with the graying of the society there is an increasing need to optimize cancer management and therapy to elderly patients. Vaccine therapy for cancer is less toxic than chemotherapy or radiation and could be, therefore, especially effective in older, more frail cancer patients. However, it has been shown that older individuals do not respond to vaccine therapy as well as younger adults. This has been attributed to T cell unresponsiveness, a phenomenon also observed in cancer patients per se. Therefore, research is needed to establish whether age-specific tumor-immunological variables permit optimal use of cancer vaccines and therapy in the elderly. This review summarizes the current knowledge of T cell unresponsiveness in cancer patients and elderly, and the results of cancer vaccination in preclinical models at young and old age. Finally, new directions that may lead to effective cancer vaccination at older age will be proposed.     

Factors Associated to Vaccination against Influenza among Elderly in a Large Brazilian Metropolis

Background

This study aimed to estimate coverage and identify factors associated to vaccination against influenza in the elderly population.

Methods

The study design was cross-sectional and population based. Data was collected in 2010 by the Health, Well-Being and Aging Study. Sample consisted of 1,341 community-dwelling elderly, in São Paulo, Brazil. Association between vaccination and covariates was evaluated by means of prevalence ratios estimated by Poisson regression models.

Results

Self-reported vaccination coverage was 74.2% (95% confidence interval: 71.3–76.9). Remaining physically active and having had recent interaction with health services, mainly with public units of healthcare, were the main incentives to increase vaccination coverage among the elderly; whereas lower age, living alone and absent interaction with health services were the main constraints to influenza vaccination at the community level. These covariates had already been reported to influence influenza vaccination of elders in previous years.

Conclusion

Previous knowledge already available on the main constraints to influenza vaccination has not allowed to remove them. Influenza campaigns should be strengthened to increase vaccination coverage, especially in the group more reticent to vaccination. Instructing healthcare providers to recommend vaccine uptake is an important piece of this puzzle.     

Reactive vaccination in the presence of disease hotspots

Reactive vaccination has recently been adopted as an outbreak response tool for cholera and other infectious diseases. Owing to the global shortage of oral cholera vaccine, health officials must quickly decide who and where to distribute limited vaccine. Targeted vaccination in transmission hotspots (i.e. areas with high transmission efficiency) may be a potential approach to efficiently allocate vaccine, however its effectiveness will likely be context-dependent. We compared strategies for allocating vaccine across multiple areas with heterogeneous transmission efficiency. We constructed metapopulation models of a cholera-like disease and compared simulated epidemics where: vaccine is targeted at areas of high or low transmission efficiency, where vaccine is distributed across the population, and where no vaccine is used. We find that connectivity between populations, transmission efficiency, vaccination timing and the amount of vaccine available all shape the performance of different allocation strategies. In highly connected settings (e.g. cities) when vaccinating early in the epidemic, targeting limited vaccine at transmission hotspots is often optimal. Once vaccination is delayed, targeting the hotspot is rarely optimal, and strategies that either spread vaccine between areas or those targeted at non-hotspots will avert more cases. Although hotspots may be an intuitive outbreak control target, we show that, in many situations, the hotspot-epidemic proceeds so fast that hotspot-targeted reactive vaccination will prevent relatively few cases, and vaccination shared across areas where transmission can be sustained is often best.     

The Temporal Trend of Influenza-Associated Morbidity and the Impact of Early Appearance of Antigenic Drifted Strains in a Southeast Asian Country

Globally, influenza infection is a major cause of morbidity and mortality in the elderly, who are suggested to be the major target group for trivalent influenza vaccine (TIV) vaccination by World Health Organization. In spite of an increasing trend in vaccine coverage rates in many countries, the effect of vaccination among the elderly in reducing hospitalization and mortality remains controversial. In this study, we conducted a historical cohort study to evaluate the temporal pattern of influenza-associated morbidity among persons older than 64 years over a decade. The temporal patterns of influenza-associated morbidity rates among the elderly older than 64 years indicated that Taiwan''s elderly P&I outpatient visits have been decreasing since the beginning of the 1999–2000 influenza season; however, hospitalization has been increasing despite significant increases in vaccine coverage. The propensity score logistic regression model was implemented to evaluate the source of bias and it was found that the TIV-receiving group had a higher propensity score than the non-receiving group (P<0.0001). In order to investigate the major factors affecting the temporal pattern of influenza-associated morbidity, we then used the propensity score as a summary confounder in a multivariate Poisson regression model based on the trimmed data. Our final models suggested that the factors affected the temporal pattern of morbidity differently. The variables including co-morbidity, vaccination rate, influenza virus type A and B isolation rate were associated with increased outpatient visits and hospitalization (p<0.05). In contrast, variables including high propensity score, increased 1°C in temperature, matching vaccine strains of type A/H1N1 and type B were associated with decreased outpatient visits and hospitalization (p<0.05). Finally, we assessed the impact of early appearance of antigenic-drifted strains and concluded that an excess influenza-associated morbidity substantial trends toward higher P&I hospitalization, but not outpatient visits, during the influenza season with early appearance of antigenic-drifted strains.