Adverse reactions to influenza vaccine in elderly people: randomised double blind placebo controlled trial.

OBJECTIVE--To assess the frequency and type of side effects after influenza vaccination in elderly people. DESIGN--Randomised double blind placebo controlled study. SETTING--15 general practices in the southern Netherlands. SUBJECTS--1806 patients aged 60 or older, of whom 904 received influenza vaccine and 902 placebo. MAIN OUTCOME MEASURES--Adverse reactions reported on postal questionnaire completed four weeks after vaccination. RESULTS--210 (23%) patients given vaccine reported one or more adverse reactions compared with 127 (14%) given placebo. The frequency of local adverse reactions were 17.5% in the vaccine group and 7.3% in the placebo group (p < 0.001). There was no difference in systemic adverse reactions (11% v 9.4%; p = 0.34). In general, men reported fewer side effects than women. CONCLUSION--Only local side effects were more common in vaccinated patients and all side effects were mild.     

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.     

Dr. Steinhart replies

Despite recommendations supporting annual influenza vaccination for people aged 65 years or older, vaccination rates remain low. Several studies have evaluated the effect of sending mailed reminders, but few have compared alternative ways of reminding patients to receive the vaccine. In a randomized trial of 939 patients aged 65 years or older in four family practices carried out between Oct. 23 and Dec. 31, 1984, we compared three ways of reminding elderly patients to receive the vaccine: personal reminder by the physician, telephone reminder by the nurse and reminder by letter. The vaccination rates for the three groups were 22.9%, 37% and 35.1% respectively. No reminder was issued to a control group, and the rate was 9.8%. Some patients could not be reached by telephone, and some did not see the physician during the specified time. Among the patients whom the nurse actually contacted, the vaccination rate was 43.5%; the rate for patients whom the doctor actually saw was 45.1%. Overall, a telephone reminder by the nurse was the most effective method, and at an hourly salary of $16 or less this method would also be the most cost-effective. The reminders used in this study were automatically generated from a computerized medical record system. The study shows how a computerized system can be used to identify patients for whom preventive procedures are due.     

The effect of adjuvants on vaccine-induced antibody response against influenza in aged mice

While influenza remains a major threat to public health, researchers continue to search for a universal solution to improving the efficacy of the influenza vaccine. Even though influenza affects people of all different ages, it can be extremely hazardous to people of 65 years of age or older since that is the population that makes up the high majority of the death toll caused by influenza-related diseases. Elderly individuals suffer the effects of immunosenescence as they age, which is the diminishing of the overall immune response. Immunosenescence occurs by specifically affecting the adaptive immune response which controls the establishment of immunity after vaccination or infection. There are many studies under way that are trying to find a resolution to the problem of the influenza vaccine not providing enough protection in the elderly population. One of the possible strategies is to seek the use of an optimal adjuvant, an immunological agent that can enhance immune responses, with the current vaccine formulation. Here, we used the murine model to review the effects of adjuvants on the antibody response to influenza vaccines in aged mice. Since adjuvants can enhance the production of important inflammatory cytokines and activation of dendritic cells, the stimulation of these cells are boosted to increase the effectiveness of the influenza vaccine in aged mice which would hopefully translate to the elderly.     

Evaluation of adverse events after influenza vaccination in hospital personnel.

Reactogenicity of trivalent influenza vaccine prepared for the 1988-89 season was assessed as part of a first-time voluntary influenza prevention program among hospital staff. Of approximately 500 full-time workers in areas with the highest concentrations of patients at high risk for influenza complications offered the vaccine 288 accepted. Of these, 266 (92%) returned a questionnaire regarding any symptoms experienced within 48 hours after vaccination; 238 (90%) of the respondents reported adverse effects. Soreness at the injection site was described by 229 subjects, 58 (25%) of whom had constant aching and 123 (54%) soreness with arm movement. Symptoms resolved in 1 to 2 days, and only 21 (9%) of those who reported symptoms said they took analgesic medication. Systemic adverse effects were described by 130 subjects (49%). Intercurrent illness accounted for some of these complaints, but 65 people (24%) described at least two of the following symptoms: generalized aching, tiredness, nausea, chills or onset of fever within 12 hours after vaccination (a symptom complex previously attributed to influenza vaccine). Systemic symptoms resolved within 0.5 to 2 days. Thirteen subjects (5%) reported missing work because of arm soreness (1 subject) or systemic symptoms (12). Adverse effects were encountered more often than expected, probably because most of the workers were young and lacked immunity to influenza. Acceptability of the program could likely be improved by using a split-virus vaccine.     

Effectiveness of non-adjuvanted pandemic influenza A vaccines for preventing pandemic influenza acute respiratory illness visits in 4 U.S. communities

We estimated the effectiveness of four monovalent pandemic influenza A (H1N1) vaccines (three unadjuvanted inactivated, one live attenuated) available in the U.S. during the pandemic. Patients with acute respiratory illness presenting to inpatient and outpatient facilities affiliated with four collaborating institutions were prospectively recruited, consented, and tested for influenza. Analyses were restricted to October 2009 through April 2010, when pandemic vaccine was available. Patients testing positive for pandemic influenza by real-time RT-PCR were cases; those testing negative were controls. Vaccine effectiveness was estimated in logistic regression models adjusted for study community, patient age, timing of illness, insurance status, enrollment site, and presence of high-risk medical conditions. Pandemic virus was detected in 1,011 (15%) of 6,757 enrolled patients. Fifteen (1%) of 1,011 influenza positive cases and 1,042 (18%) of 5,746 test-negative controls had record-verified pandemic vaccination >14 days prior to illness onset. Adjusted effectiveness (95% confidence interval) for pandemic vaccines combined was 56% (23%, 75%). Adjusted effectiveness for inactivated vaccines alone (79% of total) was 62% (25%, 81%) overall and 32% (-92%, 76%), 89% (15%, 99%), and -6% (-231%, 66%) in those aged 0.5 to 9, 10 to 49, and 50+ years, respectively. Effectiveness for the live attenuated vaccine in those aged 2 to 49 years was only demonstrated if vaccination >7 rather than >14 days prior to illness onset was considered (61%∶ 12%, 82%). Inactivated non-adjuvanted pandemic vaccines offered significant protection against confirmed pandemic influenza-associated medical care visits in young adults.     

Old people not known to the general practitioner: low risk group.

The elderly patients in a large general practice aged 75 and over who lived at home (n = 877) were divided into two groups according to the general practitioner''s knowledge of their risk status and were designated "risk status known" (n = 679) and "risk status not known" (n = 198). Forty-three high risk patients in the risk status known group had a functional disability score and experience of mortality that was not dissimilar to those of elderly people in institutions. The medical and social characteristics of a random sample (n = 150) of the risk status known group, after excluding the high risk patients, were compared with the risk status not known group using a Barber Wallis questionnaire. A response rate of 90% was achieved from both groups and a cumulative risk score was calculated by totalling unfavourable replies to the questions. The risk status not known group, which comprised 14% of the patients who lived at home after correcting for the number who had died and moved, had appreciably less contact with the general practitioners, had an appreciably lower cumulative risk score, were confined at home less because of ill health, were less concerned about their health, and were less in need of nursing attention. The findings of this study suggest that the elderly patients who are not known to their general practitioners are in relatively good health when compared with the patients that the general practitioner knows well.     

Compliance with diphtheria,tetanus, and pertussis immunisation in Bangladesh: factors identifying high risk groups.

OBJECTIVE--To evaluate factors associated with non-compliance with having second vaccination against diphtheria, tetanus, and pertussis in a treatment centre in Dhaka to determine which children were most at risk of not completing immunisation. DESIGN--Cohort study of infants given first dose of the vaccine and followed up six weeks later to ascertain compliance with having second dose. Factors associated with non-compliance were evaluated. SETTING--Dhaka treatment centre of the International Centre for Diarrhoeal Disease Research, Bangladesh. SUBJECTS--136 unimmunised children aged 6 weeks to 23 months who lived within reach of the treatment centre. At time of the six week follow up 16 of the children could not be traced and seven had died. INTERVENTIONS--All children received their first dose of the vaccine. In each case health education workers had informed the mother about the value of immunisation, and she was given clear instructions to bring the child back after four weeks for the second dose. MAIN OUTCOME MEASURE--Rate of non-compliance with advice to return child for second vaccination. RESULTS--46 of 113 children (41%) received the second dose of the vaccine. Factors most closely associated with mothers'' failure to comply with the second dose were lack of education and low income. Children whose mothers knew most about immunisation at first interview were more likely to have their second dose. CONCLUSIONS--Preventive health care services such as immunisation are appropriately offered in treatment centres, but compliance among children varies with socioeconomic status and mother''s education. Further research should be aimed at ways to make health education more effective among uneducated parents.     

Effects of Vaccination and the New Neuraminidase Inhibitor,Laninamivir, on Influenza Infection

Background

Evidence of the effectiveness of influenza vaccination in children and elderly adults is limited, although this population has the highest risk for influenza infection.

Materials and Methods

We enrolled 4443 participants, aged 3–97 years, who had influenza-kit-positive resultsduring seasons 2007–12, including 2135 with influenza A, 534 with A/H1N1, and 1643 with influenza B. Eligible subjects completed a questionnaire to identify past influenza infection and vaccination history. For the diagnosis of current influenza infection, subjects were examined, and pharyngeal swabs were collected and tested using the Capilia flu rapid diagnosis kit to confirm influenza infection. An interim analysis was performed using clinician-based surveillance data for the entire four seasons of influenza infection in Japan.

Results

In 3035 adultsaged 14–64 years, administration of the influenza vaccine significantly reduced the frequency of infection (P<0.01) in the 2008 and 2010 seasons, but not in the 2009 and 2011 seasons. Moreover, the vaccine did not reduce the frequency of infection in children (aged <13 years) and older adults (aged >65 years) significantly. Laninamivir, oseltamivir phosphate, zanamivir hydrate, and amantadine hydrochloride were administered to 1381, 2432, 1044, and 100 patients, respectively. They were effective in >97% of patients, with no significant differences being found. Adverse effects were few. However, the recurrence rate of influenza infection after treatment was significantly reduced in patients who received laninamivir compared with that in those who received oseltamivir and zanamivir (P<0.01). The effectiveness of laninamivirdid not decrease.

Conclusions

The vaccines administered had limited efficacy in reducing the frequency of influenza infection in young adults. Laninamivir significantly reduced the recurrence of influenza infection when compared with other neuraminidase inhibitors.     

Suboptimal Effectiveness of the 2011–2012 Seasonal Influenza Vaccine in Adult Korean Populations

Background

The effectiveness of the 2011–2012 seasonal influenza vaccine was evaluated in adult Korean populations with regard to how well it could prevent laboratory-confirmed influenza and influenza-related complications.

Materials and Methods

A retrospective case-control and retrospective cohort study was conducted among patients who visited four selected hospitals from September 2011 to May 2012. The analysis included 1,130 laboratory-confirmed influenza patients. For each influenza case, one control patient was chosen at a ratio of 1:1. A control was defined as an age group-matched patient who visited the same hospital with influenza-like illness within 48 hours of symptom onset but for whom laboratory tests were negative for influenza. Age group and visit date were matched between the cases and controls. Vaccine effectiveness (VE) was defined as [100 × (1-odds ratio for influenza in vaccinated versus non-vaccinated persons)]. The patients with laboratory-confirmed influenza were followed for at least one month through reviewing the medical records and conducting a telephone interview.

Results

The VE of the 2011–2012 seasonal influenza vaccine was 3.8% [95% confidence interval (CI), -16.5% to 20.6%] for preventing laboratory-confirmed influenza, -16.1% (95% CI, -48.3 to 9.1) for influenza A and 26.2% (95% CI, -2.6 to 46.2) for influenza B. The age-specific adjusted VE was 0.3% (95% CI, -29.4 to 23.1) among participants aged 19 to 49 years, 11.9% (95% CI, -34.3 to 42.2) among those aged 50 to 64 years and -3.9% (-60.1 to 32.5) among those aged ≥65 years. The adjusted VE for preventing any influenza-related complications was -10.7% (95% CI, -41.1% to 42.2%).

Conclusions

The 2011–2012 seasonal influenza vaccine was not effective in preventing laboratory-confirmed influenza or influenza-related complications in adult Korean populations.     

Adverse reactions to 1975 bivalent influenza vaccine in children.

A questionnaire survey was undertaken to investigate incidence and types of reactions to a bivalent, zonally purified, killed influenza vaccine administered to 155 children aged 1 to 18 years in 1975. Local or systemic reactions or both occurred in 42 children (27%). However, these reactions were not considered serious and should not constitute a major drawback to future influenza programs in children under 3 years of age.     

Blockage of regulatory T cells augments induction of protective immune responses by influenza virus-like particles in aged mice

Elderly humans over 65 years old are at great risk to pathogenesis by influenza virus infection. However, although influenza vaccines provide effective protection in healthy young adults, protection of elderly adults is substantially lower even with a good match between the vaccine and the circulating influenza virus. To gain insight of the underlying mechanism for the reduced immunogenicity of influenza vaccines in the aged population, we investigated immunogenicity of influenza virus-like particle vaccines in aged mice, which represent a useful model for studying aging associated impairment in immune responses. Specifically, we investigated the effect of inhibiting regulatory T cells in aged mice on induction of protective immune responses by influenza vaccines. Our results showed that injecting anti-CD25 antibodies could down-regulate CD25 on the surface of regulatory T cells and significantly increase the levels of antibody responses induced by VLP immunization in aged mice. Further, the profiles of antibody responses were also changed towards Th1 type by regulatory T cell blockage in aged mice. Moreover, aged mice that were treated by anti-CD25 antibodies prior to vaccination were more effectively protected against lethal influenza virus challenge.     

Total immunization of children against influenza decreases morbidity in a number of diseases among elderly persons during influenza epidemic

Immunization of children aged 3-6 years in kindergartens and school children aged 7-17 years against influenza with inactivated influenza vaccine was carried out in two districts of the Moscow region. The comparison of morbidity in influenza-like diseases among the immunized children with that among nonimmunized children in control districts revealed that the effectiveness of immunization was 60.9% in kindergartens and 68.8% in schools. The analysis of morbidity in a number of diseases among 158,451 elderly persons not immunized against influenza demonstrated that, in comparison with the control districts, in those districts where mass immunization of children was carried out morbidity in influenza-like diseases among elderly persons was 3.4 times lower and, out of other 10 diseases under study, morbidity in 8 diseases was 1.5-2.6 times lower. As indicated by the data obtained in this study, total anti-influenza immunization of children in organized groups not only essentially decreased influenza morbidity among children, but also greatly decreased morbidity in influenza and a number of diseases, appearing as complications of influenza infection, among nonimmunized elderly persons during influenza epidemic.     

Effect of preventive home visits by a nurse on the outcomes of frail elderly people in the community: a randomized controlled trial

BACKGROUND: Timely recognition and prevention of health problems among elderly people have been shown to improve their health. In this randomized controlled trial the authors examined the impact of preventive home visits by a nurse compared with usual care on the outcomes of frail elderly people living in the community. METHODS: A screening questionnaire identified eligible participants (those aged 70 years or more at risk of sudden deterioration in health). Those randomly assigned to the visiting nurse group were assessed and followed up in their homes for 14 months. The primary outcome measure was the combined rate of deaths and admissions to an institution, and the secondary outcome measure the rate of health services utilization, during the 14 months; these rates were determined through a medical chart audit by a research nurse who was blind to group allocation. RESULTS: The questionnaire was mailed to 415 elderly people, of whom 369 (88.9%) responded. Of these, 198 (53.7%) were eligible, and 142 consented to participate and were randomly assigned to either the visiting nurse group (73) or the usual care group (69). The combined rate of deaths and admissions to an institution was 10.0% in the visiting nurse group and 5.8% in the usual care group (p = 0.52). The rate of health services utilization did not differ significantly between the 2 groups. Influenza and pneumonia vaccination rates were significantly higher in the visiting nurse group (90.1% and 81.9%) than in the usual care group (53.0% and 0%) (p < 0.001). INTERPRETATION: The trial failed to show any effect of a visiting nurse other than vastly improved vaccination coverage.     

Knowledge of and Attitudes to Influenza Vaccination in Healthy Primary Healthcare Workers in Spain, 2011-2012

Annual influenza vaccination is recommended for healthcare workers, but many do not follow the recommendation. The objective of this study was to investigate the factors associated with seasonal influenza vaccination in the 2011–2012 season. We carried out an anonymous web survey of Spanish primary healthcare workers in 2012. Information on vaccination, and knowledge and attitudes about the influenza vaccine was collected. Workers with medical conditions that contraindicated vaccination and those with high risk conditions were excluded. Multivariate analysis was performed using unconditional logistic regression. We included 1,749 workers. The overall vaccination coverage was 50.7% and was higher in workers aged ≥ 55 years (55.7%), males (57.4%) and paediatricians (63.1%). Factors associated with vaccination were concern about infection at work (aOR 4.93; 95% CI 3.72–6.53), considering that vaccination of heathcare workers is important (aOR 2.62; 95%CI 1.83–3.75) and that vaccination is effective in preventing influenza and its complications (aOR 2.40; 95% CI 1.56–3.67). No association was found between vaccination and knowledge of influenza or the vaccine characteristics. Educational programs should aim to remove the misconceptions and attitudes that limit compliance with recommendations about influenza vaccination in primary healthcare workers rather than only increasing knowledge about influenza and the characteristics of the vaccine.     

Risk factors for lower respiratory complications of rhinovirus infections in elderly people living in the community: prospective cohort study.

OBJECTIVE: To assess the role of rhinoviruses in elderly people living in the community. DESIGN: Prospective community based surveillance of elderly people, without intervention. Subjects were telephoned weekly to identify symptomatic upper respiratory tract infections. Symptoms and impact of illnesses were monitored, and specimens were collected for diagnostic serology and human rhinovirus polymerase chain reaction. SETTING: Leicestershire, England. SUBJECTS: 533 subjects aged 60 to 90. MAIN OUTCOME MEASURES: Symptoms, restriction of activity, medical consultations, and antibiotic use during 96 rhinovirus infections. Adjusted odds ratios for lower respiratory syndromes with respect to smoking and health status. RESULTS: A viral cause was established in 211 (43%) of 497 respiratory illnesses; rhinoviruses were identified in 121 (24%) and as single pathogens in 107. The median duration of the first or only rhinovirus infection in the 96 people with 107 rhinovirus infections was 16 days; 18 of the 96 patients were confined to bed and 25 were unable to cope with routine household activities. Overall, 60 patients with rhinovirus infections had lower respiratory tract syndromes; 41 patients consulted their doctor, 31 of them (76%) receiving antibiotics. One patient died. Logistic regression analysis showed that chronic medical conditions increased the estimated probability of lower respiratory rhinovirus illness by 40% (95% confidence interval 17% to 68%) and smoking by 47% (14% to 90%). There were almost six times as many symptomatic rhinovirus infections as influenza A and B infections. CONCLUSIONS: Rhinoviruses are an important cause of debility and lower respiratory illness among elderly people in the community. Chronic ill health and smoking increase the likelihood of lower respiratory complications from such infections. The overall burden of rhinovirus infections in elderly people may approach that of influenza.     

Health-Related Behaviors and Effectiveness of Trivalent Inactivated versus Live Attenuated Influenza Vaccine in Preventing Influenza-Like Illness among Young Adults

Background

Vaccination is the preferred preventive strategy against influenza. Though health behaviors are known to affect immunity and vaccine delivery modes utilize different immune processes, data regarding the preferred influenza vaccine type among adults endorsing specific health-related behaviors (alcohol use, tobacco use, and exercise level) are limited.

Methods

The relative effectiveness of two currently available influenza vaccines were compared for prevention of influenza-like illness during 2 well-matched influenza seasons (2006/2007, 2008/2009) among US military personnel aged 18–49 years. Relative vaccine effectiveness was compared between those self-reporting and not reporting recent smoking history and potential alcohol problem, and by exercise level using Cox proportional hazard modeling adjusted for sociodemographic and military factors, geographic area, and other health behaviors.

Results

28,929 vaccination events and 3936 influenza-like illness events over both influenza seasons were studied. Of subjects, 27.5% were smokers, 7.7% had a potential alcohol-related problem, 10.5% reported minimal exercise, and 4.4% reported high exercise levels. Overall, the risk of influenza-like illness did not significantly differ between live attenuated and trivalent inactivated influenza vaccine recipients (hazard ratio, 0.98; 95% confidence interval, 0.90–1.06). In the final adjusted model, the relative effectiveness of the 2 vaccine types did not differ by smoking status (p = 0.10), alcohol status (p = 0.21), or activity level (p = 0.11).

Conclusions

Live attenuated and trivalent inactivated influenza vaccines were similarly effective in preventing influenza-like illness among young adults and did not differ by health-related behavior status. Influenza vaccine efforts should continue to focus simply on delivering vaccine.     

Influenza vaccination coverage across ethnic groups in Canada

Background:

The success of influenza vaccination campaigns may be suboptimal if subgroups of the population face unique barriers or have misconceptions about vaccination. We conducted a national study to estimate influenza vaccine coverage across 12 ethnic groups in Canada to assess the presence of ethnic disparities.

Methods:

We pooled responses to the Canadian Community Health Survey between 2003 and 2009 (n = 437 488). We estimated ethnicity-specific self-reported influenza vaccine coverage for the overall population, for people aged 65 years and older, and for people aged 12–64 years with and without chronic conditions. We used weighted logistic regression models to examine the association between ethnicity and influenza vaccination, adjusting for sociodemographic factors and health status.

Results:

Influenza vaccination coverage ranged from 25% to 41% across ethnic groups. After adjusting for sociodemographic factors and health status for people aged 12 years and older, all ethnic groups were more likely to have received a vaccination against influenza than people who self-identified as white, with the exception of those who self-identified as black (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.88–1.15). Compared with white Canadians, Canadians of Filipino (OR 2.00, 95% CI 1.67–2.40) and Southeast Asian (OR 1.66, 95% CI 1.36–2.03) descent had the greatest likelihood of having received vaccination against influenza.

Interpretation:

Influenza vaccine coverage in Canada varies by ethnicity. Black and white Canadians have the lowest uptake of influenza vaccine of the ethnic groups represented in our study. Further research is needed to understand the facilitators, barriers and misconceptions relating to vaccination that exist across ethnic groups, and to identify promotional strategies that may improve uptake among black and white Canadians.Accurate and reliable data on vaccine coverage are essential for evaluating the success of influenza vaccination campaigns. Identifying populations with suboptimal coverage can help program planners design effective, targeted health-promotion strategies. Vaccine coverage has traditionally been described by age and sex;¹ little research in Canada has examined coverage by ethnicity.Many studies in the United States have shown large ethnic disparities (> 15%) in coverage between people who self-identify as white, black or Hispanic among adults with high-risk conditions,² older adults^3,4 and Medicare beneficiaries.⁵ The reasons for these disparities are complex and may be related to attitudes and knowledge about vaccination, access to health care, socioeconomic status and provider bias.⁶ However, these findings cannot be applied to the Canadian population, which is distinct in terms of the delivery of influenza vaccinations and ethnic composition. Since the late 1970s, the number of non-European immigrants to Canada has risen, contributing to a substantial increase in the visible minority population, from 4.7% of the total population in 1981 to 16.2% in 2006.⁷ More than 200 different ethnic origins were reported in the 2006 Census,⁸ with people of South Asian (4.0%), Chinese (3.9%) and black (2.5%) heritage representing the largest proportions of the population.Canada’s National Advisory Committee on Immunization recommends vaccination against influenza for people at high risk of serious infection and their contacts.⁹ The largest risk groups are adults 65 years of age and older and people with certain chronic medical conditions (e.g., cardiac and pulmonary disorders, diabetes, cancer, immune-compromising conditions, renal disease, anemia and obesity). Every province and territory provides free influenza vaccinations to these priority groups. Since 2000, Ontario has provided publicly funded influenza vaccinations to all people older than 6 months of age. Other jurisdictions (Alberta, Manitoba, Saskatchewan, Nova Scotia, Nunavut, Yukon and Northwest Territories) have subsequently adopted similar programs.¹⁰ Although these initiatives should reduce financial barriers to vaccination, there may be other barriers or misconceptions unique to specific groups that affect behaviour.The purpose of this study was to estimate influenza vaccine coverage across 12 ethnic groups in Canada to assess possible disparities.     

A TritonX-100-split Virion Influenza Vaccine is Safe and Fulfills the Committee for Proprietary Medicinal Products (CPMP) Recommendations for the European Community for Immunogenicity,in Children,Adults and the Elderly

Influenza epidemics are an important cause of morbidity and mortality throughout the world. Current recommendations from Health Authorities emphasize annual immunization of people who are particularly at risk from an influenza virus infection; however, vaccination of working adults and of school children also has been shown to provide public health benefits. To give it a more advantageous reactogenicity profile than the diethylether-split influenza vaccines available previously, a split virion influenza vaccine has been produced with TritonX-100. In a series of clinical trials, Aventis Pasteur (formerly, Pasteur Mérieux Connaught) tested both the safety and immunogenicity of this TritonX-100-split virion influenza vaccine in 566 subjects (42 children, 296 adults, and 228 elderly adults) during three influenza seasons (1991, 1993, and 1995). The TritonX-100-split virion vaccine was well tolerated: no serious adverse events were recorded during the 21 days following immunization. Among the local reactions observed, mild pain, redness, or induration at the injection site were the most frequently reported. Fever (38·0 to 38·5°C) was noted in five adults or elderly subjects (1%), and in two children (5%). Immunogenicity was determined by measuring serum haemagglutinin antibody titres specific to each vaccine virus strain. In each of the three vaccination campaigns, the TritonX-100-split virion influenza vaccine fulfilled the Notes for Guidance on Harmonization of Requirements for Influenza Vaccines outlined by the Committee for Proprietary Medicinal Products (CPMP) of the European Community for an influenza virus vaccine (i.e., seroprotection, seroconversion, or increase of geometric mean titre) in all age groups.