Influenza vaccination as secondary prevention for cardiovascular disease: a science advisory from the American Heart Association/American College of Cardiology

Evidence from cohort studies and a randomized clinical trial indicates that annual vaccination against seasonal influenza prevents cardiovascular morbidity and all-cause mortality in patients with cardiovascular conditions. The American Heart Association and American College of Cardiology recommend influenza immunization with inactivated vaccine (administered intramuscularly) as part of comprehensive secondary prevention in persons with coronary and other atherosclerotic vascular disease (Class I, Level B). Immunization with live, attenuated vaccine (administered intranasally) is not currently recommended [corrected] for persons with cardiovascular conditions. It is important to note that influenza vaccination coverage levels overall and in this population remain well below national goals and are marked by disparities across different age and ethnic groups. One of the barriers to vaccination for patients with cardiovascular disease is that cardiology practices frequently do not stock and administer influenza vaccine. Healthcare providers who treat individuals with cardiovascular disease can help improve influenza vaccination coverage rates by providing and strongly recommending vaccination to their patients before and throughout the influenza season.     

Influenza vaccination as secondary prevention for cardiovascular disease: a science advisory from the American Heart Association/American College of Cardiology.

Evidence from cohort studies and a randomized clinical trial indicates that annual vaccination against seasonal influenza prevents cardiovascular morbidity and all-cause mortality in patients with cardiovascular conditions. The American Heart Association and American College of Cardiology recommend influenza immunization with inactivated vaccine (administered intramuscularly) as part of comprehensive secondary prevention in persons with coronary and other atherosclerotic vascular disease (Class I, Level B). Immunization with live, attenuated vaccine (administered intranasally) is not currently recommended [corrected] for persons with cardiovascular conditions. It is important to note that influenza vaccination coverage levels overall and in this population remain well below national goals and are marked by disparities across different age and ethnic groups. One of the barriers to vaccination for patients with cardiovascular disease is that cardiology practices frequently do not stock and administer influenza vaccine. Healthcare providers who treat individuals with cardiovascular disease can help improve influenza vaccination coverage rates by providing and strongly recommending vaccination to their patients before and throughout the influenza season.     

Influenza vaccination of persons with cardiovascular disease in the United States

People who have cardiovascular disease are at increased risk of hospitalization or death associated with influenza infection, and are included among the high-risk groups for whom annual influenza vaccination is recommended. To measure the progress toward the national year 2000 and 2010 objectives of a 60% annual influenza vaccination of adults with high-risk conditions aged 18 to 64 years, we analyzed data from the 1997 to 2001 National Health Interview Surveys (NHIS) regarding persons with cardiovascular disease. The NHIS is an annual, cross-sectional survey representative of the U.S., noninstitutionalized, civilian population. Estimated percentages of persons with heart disease reporting influenza vaccination were relatively stable during the 1996-97 through 2000-2001 influenza seasons, with the highest levels in most groups occurring in 1999-2000: 49.2% (95% confidence interval [CI], 44.1%-54.3%) among persons aged 50 to 64 years; and 22.7% (95% CI, 18.2%-27.2%) among persons aged 18 to 49 years. Influenza vaccine coverage among adults aged 18 to 64 years with cardiovascular disease is substantially below the national objective. Multiple strategies are needed to improve vaccination coverage, such as increasing the awareness of and demand for vaccination by persons with heart disease; increasing implementation by providers of practices that have been shown to increase vaccination levels; and adopting of influenza vaccination by primary care providers and specialists as a standard of care for persons diagnosed with cardiovascular disease.     

Prevention and control of influenza in persons with chronic obstructive pulmonary disease

Despite recommendations for annual vaccination against influenza, more than half of patients with chronic obstructive pulmonary disease (COPD) in developed countries do not receive this vaccine. Influenza is characterized by its potentially of causing epidemics and by excess morbidity and mortality in patients with COPD and other chronic medical conditions. Good evidence of the efficacy, effectiveness, and cost-effectiveness of influenza vaccination underlines the recommendation of use in patients with COPD. Influenza vaccination could reduce influenza-related complications and exacerbations in patients with COPD, therefore reducing hospitalizations and deaths. Each year, all persons with COPD should be vaccinated with the inactivated trivalent influenza vaccine containing the most frequent two influenza A viral strains and one influenza B viral strain detected in the influenza season of the previous year. To achieve a 100% vaccination rate in patients with COPD, all patients with COPD registered in health insurance companies and attended in health centers and specialized clinics should be vaccinated during the immunization period (October–December). Antiviral therapies could be used as an adjunct to vaccination and to reduce influenza transmission in outbreaks. Antiviral therapies could reduce the duration and complications of influenza when administered within two days of the onset of illness. Research is necessary for new antiviral therapies that could prevent influenza with cost-effectiveness similar to the influenza vaccine.     

Where adults reported receiving influenza vaccination in the United States

BACKGROUND: Influenza vaccination coverage remains unacceptably low among persons aged > or =65 years and younger high-risk adults. This study assessed locations at which US adults receive influenza (flu) vaccinations and the relative roles that traditional and nontraditional vaccination settings play in influenza vaccine delivery. METHODS: We analyzed data on types of settings at which last flu shot was received, reported by adult respondents to the 1999 Behavioral Risk Factor Surveillance System, stratified by age group and medical condition. We used multivariable logistic regression to identify factors associated with nontraditional vaccination settings. RESULTS: In 1998-1999, reported influenza vaccination coverage was 19% for persons aged 18-49 years, 36% for persons aged 50-64 years, and 67% for persons aged > or =65 years. Seventy percent of flu shots received by persons aged > or =18 years were reportedly administered in doctors' offices and other traditional settings. Vaccination in nontraditional settings (eg, workplace, stores, community centers) was more likely for young, healthy, employed, white, college-educated adults who had not had a recent routine checkup. CONCLUSION: Physicians should offer vaccination services at every opportunity. Increasing access to vaccination services in nontraditional settings should be considered as another strategy in pursuit of national vaccination coverage objectives.     

Racial Disparity in Flu Vaccine Uptake Among Asian American Individuals: A National Health Interview Survey Study

Vaccination coverage rates across Asian American subpopulations with atherosclerotic cardiovascular disease (ASCVD) and diabetes mellitus is not well-studied. We used data from the National Health Interview Survey (NHIS) from 2006 to 2018 and included participants with a history of ASCVD or diabetes. Vaccination coverage in White were compared with Chinese, Asian Indian, Filipino, and “other Asian” (Japanese, Korean, and Vietnamese) adults using univariable and multivariable logistic regression models. We included 50,839 participants, mean age 62.7 ± 0.1 years, 46.3% women, 89.1% US-born. Filipino (59%) and Asian Indian (56%) adults were less likely to receive influenza vaccine than “other Asians” (66%), Chinese (65%), and White (60%) participants (P < 0.001). In multivariable adjusted models, Chinese (OR = 1.66, 1.02-2.69), Asian Indian (OR = 1.50, 1.07-2.10), and “other Asian” ethnicity (OR = 1.81, 1.38-2.36) were associated with higher odds of receiving influenza vaccination compared with White. Influenza vaccine coverage remains suboptimal across all studied races/ethnicities.     

Influenza Vaccination Coverage Rates in 5 European Countries: a Population-Based Cross-Sectional Analysis of the Seasons 02/03, 03/04 and 04/05

Abstract Introduction: Influenza continues to be a considerable health problem in Europe. Vaccination is the only preventive measure, reducing mortality and morbidity of influenza in all age groups Objectives: The objective of this survey was to assess and compare the level of influenza vaccination coverage during three consecutive influenza seasons (02/03, 03/04, 04/05) in the five European countries United Kingdom, France, Italy, Germany and Spain, understand the driving forces and barriers to vaccination now and 3 years ago and determine vaccination intentions for the following winter. Methods: We conducted a random-sampling, telephone-based household survey among non-institutionalized individuals representative of the population aged 14 and over. The surveys used the same questionnaire for all three seasons. The data were subsequently pooled. Four target groups were determined for analysis: (1) persons aged 65 and over; (2) people working in the medical field; (3) persons suffering from chronic illness and (4) a group composed of persons aged 65 and over or working in the medical field or suffering from a chronic illness. Results: The overall sample consisted of 28,021 people. The influenza vaccination coverage rate increased from 21.0% in season 02/03 to 23.6% in season 03/04 and then to 23.7% in season 04/05. The differences between the seasons are statistically significant (p = 0.01). The highest rate over all countries and seasons had Germany in season 04/05 with 26.5%, Spain had in season 02/03 with 19.3% the lowest rate totally. The coverage rate in the target group composed of person's aged 65 and over or working in the medical field or suffering from a chronic illness was 49.7% in season 02–04 and 50.0% in season 04/05. The driving forces and barriers to vaccination did not change over the years. The most frequent reasons for being vaccinated given by vaccines were: influenza, considered to be a serious illness which people wanted to avoid, having received advise from the family doctor or nurse to be vaccinated and not wanting to infect family and friends. Reasons for not being vaccinated mentioned by people who have never been vaccinated were: not expecting to catch influenza, not having considered vaccination before and not having received a recommendation from the family doctor to be vaccinated. Options encouraging influenza vaccination are: recommendation by the family doctor or nurse, more available information on the vaccine regarding efficacy and tolerance and more information available about the disease. The adjusted odds ratio of receiving influenza vaccine varied between 2.5 in Germany and 6.3 in the United Kingdom in any risk group. Conclusion: The vaccination coverage rate increased from the first season (21.0%) to the third season (23.7%) by 2.6%. The family doctor is the most important source of encouragement for people to be vaccinated against influenza. It seems that the public would be more likely to be vaccinated if they had more information on the efficacy and tolerance of the vaccine, as well as the disease. We therefore suggest that family doctors be better informed on influenza vaccine and the disease itself, so that they can actively inform their patients on these topics.     

Safety and tolerability of intradermal influenza vaccination in patients with cardiovascular disease

Background It is well-established that influenza vaccination reduces adverse cardiovascular outcomes in patients with cardiovascular diseases （CVD）, however, the vaccine coverage rate in most countries remains low. The concern about the local adverse effects of intramus-cular injection, particularly in CVD patients receiving antithrombotic therapy, is one of the important impediments. This study was con-ducted to assess the safety, side effects and tolerability of intradermal influenza vaccine in CVD patients. Methods This was an observa-tional study in adult CVD patients who had undergone vaccination against seasonal influenza by intradermal vaccination between May 16th and May 30th, 2012 at Maharaj Nakorn Chiang Mai Hospital. The medical history, patients＇ acceptability and adverse effects were collected using a written questionnaire completed by the patient immediately following vaccination and by a telephone survey eight days later. Results Among 169 patients, 52.1%were women and the mean age was 63 ＆#177; 12 years. Coronary artery disease, valvular heart disease and dilated cardiomyopathy were present in 121 （71.6%）, 40 （23.7%） and 8 （4.7%）, respectively. Antithrombotics were used in 89.3%. After vaccination, the pain score was 0, 1 or 2 （out of 10） in 44.4%, 15.1%, and 27.6%of the patients, respectively. Eight days after vaccination, the common adverse reactions were itching 19 （11.9%）, swelling 9 （5.7%） and fatigue （4.7%）. No hematoma or bruising was reported. Conclusions The intradermal influenza vaccination is safe and well tolerates with high rates of satisfaction in CVD patients. This technique should be useful in expanding influenza vaccine coverage.     

Influenza and pneumococcal vaccination among Native American elders in a primary care practice

BACKGROUND: More than 2 million Native Americans (ie, Native Americans and Native Alaskans) live in the United States; 60% reside in cities. This population, especially its elders, is especially susceptible to respiratory diseases; yet, adherence to guidelines for influenza and pneumococcal immunizations is unknown. OBJECTIVES: To evaluate how frequently older and high-risk adults received vaccinations for influenza and pneumococcal infection and to identify patient characteristics associated with adherence to published recommendations. METHODS: Retrospective medical record review of 550 Native American elders seen in an urban primary care practice defined using a culturally appropriate age threshold (> or =50 years) and standard criteria (> or =65 years). Univariate analyses examined demographic and clinical information by vaccination status. Logistic regressions identified factors associated with adherence to immunization guidelines. RESULTS: Among patients aged 50 years and older with any indication according to published recommendations, rates were low for influenza (31%) and pneumococcal (21%) immunizations. Likewise, few subjects at least 65 years of age had been immunized appropriately against influenza (38%) or pneumococcus (32%). Younger age and alcohol use were significantly associated with less frequent immunization; Medicare insurance, depression, and more health problems and taking more medications predicted significantly higher immunization rates. Aged 65 years or older and having cardiovascular disease or diabetes mellitus were specific indications significantly correlated with receipt of influenza and pneumococcal vaccine. CONCLUSIONS: Regardless of age or risk, inadequate vaccination rates were observed in elderly Native Americans. Our findings suggest the need to identify obstacles to immunization and to conduct prospective and elderly intervention studies in Native American populations.     

Efficacy of influenza vaccine among geriatric inpatients: effect of previous vaccination and antibody induction by single and twice injections

To investigate the effect of previous influenza vaccination and the difference in antibody induction by single and twice injection of influenza vaccine in the elderly, hemagglutination inhibition (HI) antibody titers of the three types of influenza viruses were measured. Influenza vaccination was done for 217 inpatients. For the patients who had influenza vaccination in the year prior to the study, influenza vaccine was administered once to 77 patients and twice to another 70 patients. Influenza vaccine was injected twice to 70 patients who had not received influenza vaccine in the previous years. The influenza vaccine induced an increase in HI titer in almost all patients. The geometric mean of the HI titer and the frequency of patients with HI titers over 128x were similar after vaccination in the groups of patients who were injected twice, irrespective of whether or not influenza vaccination was given in the year prior to the study. The geometric means of the HI titers for influenzas A/H3N2 and B and the frequency of HI titers over 128x for influenza A/H3N2 after vaccination were lower in the patients who received vaccine once than in the patients vaccinated twice. These results suggest that prior vaccination does not diminish antibody response to influenza vaccine significantly in the elderly when influenza vaccine is injected twice. Although single injection is inferior to twice injection in antibody induction with some vaccine virus strains, induction of HI titers over 128x is found in more than 70% of elderly. Single injection of influenza vaccine may be practically effective and useful for protection of influenza infection in the elderly.     

Racial similarities in response to standardized offer of influenza vaccination

BACKGROUND: Despite known benefits of influenza vaccination and coverage by Medicare Part B, elderly minority patients are less likely to receive influenza vaccination than whites. OBJECTIVES: To test whether a nonphysician-initiated standardized offer of influenza vaccination to all elderly primary care patients would result in similar proportions of African-American and white patients accepting vaccine. DESIGN: In 7 metropolitan Detroit primary care practices during the 2003 influenza vaccination season, medical assistants assessed influenza immunization status of all patients 65 years and older and collected limited demographic data. Eligible patients were offered vaccination. MEASUREMENTS: Proportion of patients accepting influenza vaccination by race and predictors of vaccine acceptance. RESULTS: Four hundred and fifty-four eligible patients with complete racial information were enrolled: 40% African American, 52% white, 8% other race/ethnicity. Similar proportions of African Americans and whites had already received the 2003 vaccine (11.6% and 11.0%, respectively) or stated vaccination as the reason for visit (23.8% and 30.5%, respectively). Among the remainder, there also were similar proportions who accepted vaccination: 68.9% white and 62.1% African-American patients. History of previous vaccination was the only statistically significant predictor of vaccine acceptance (odds ratio [OR] 8.64, 95% confidence interval [CI] 4.17, 17.91, P<.001). After adjusting for history of previous vaccination, age, gender, and education, the odds of vaccine acceptance were no different for whites and African Americans (OR 1.20, 95% CI 0.63, 2.29, P=.57). CONCLUSIONS: Vaccination acceptance differed little between African-American and white elderly patients. Using nonphysician personnel to identify and offer influenza vaccine to eligible patients is easily accomplished in primary care offices and has the potential to eliminate racial disparities in influenza vaccination.     

The association of sociodemographic factors and patient attitudes on influenza vaccination rates in older persons

BACKGROUND: To determine how patient attitudes, beliefs, knowledge, and sociodemographic characteristics relate to influenza vaccine acceptance in an older patient population. METHODS: We conducted a mail survey of patients enrolled in a geriatrics clinic at a university-affiliated county hospital in Seattle, WA. We surveyed senior citizens' demographic background, health status, previous experiences, and beliefs about influenza and influenza vaccine. We determined the vaccination rates for influenza season 2001-2002 stratified by race, other sociodemographic factors, and attitudes toward influenza vaccination. RESULTS: Surveys were mailed to 572 enrollees in SeniorCare Clinic. Three hundred twenty-four (57%) responded to the survey, 256 (79%) of whom reported receipt of influenza vaccination. Influenza vaccination rates did not vary significantly by race in this patient population: 80% for white persons, 70% for black persons, and 84% for Asians. Receipt of vaccination was associated with survey responses that indicated a discussion about the influenza shot with a health care provider and a positive attitude toward the influenza shot. History of side effects and negative attitude toward the influenza shot were associated with failure to receive the vaccine. CONCLUSIONS: In patients served by a university-affiliated geriatrics clinic, we found no statistically significant difference in influenza vaccination rate between white persons and other racial groups. Attitudes, beliefs, knowledge, and prior experiences toward the influenza shot were predictors of influenza vaccination. Physician recommendation and patient participation strongly correlated with vaccination acceptance.     

Efficacy and safety of influenza vaccination to elderly patients with neurological diseases]

Influenza vaccination is strongly recommended for the elderly persons. Especially elderly patients with neurological diseases are at the high risk because they have more tendencies to develop pneumonia than healthy elderly persons. We vaccinated 105 elderly patients with neurological diseases (cerebrovascular disease, Parkinson disease etc.) and 134 people of a control group. Both groups were inoculated with influenza HA vaccine once. The HI titer increase in elderly patients with neurological diseases was equally good enough in the control group and no significant differences was shown in both groups. No severe side effects and adverse reactions were observed in the elderly patient group. This study shows that influenza vaccination is effective and safe for elderly patients with neurological diseases as the well as healthy elderly person and the HI titer increase after a single influenza vaccine injection is expected to be effective to protect influenza infection.     

Relation between influenza vaccination and outpatient visits, hospitalization, and mortality in elderly persons with chronic lung disease

BACKGROUND: Influenza vaccine is underused in groups targeted for vaccination. OBJECTIVE: To define the effects of influenza and the benefits of influenza vaccination in elderly persons with chronic lung disease. DESIGN: Retrospective, multiseason cohort study. SETTING: Large managed care organization. PATIENTS: All elderly members of a managed care organization who had a previous diagnosis of chronic lung disease. MEASUREMENTS: Outcomes in vaccinated and unvaccinated persons for the 1993-1994, 1994-1995, and 1995-1996 influenza seasons were compared after adjustment for baseline demographic and health characteristics. All data were obtained from administrative databases. RESULTS: Vaccination rates were greater than 70% for each season. Among unvaccinated persons, hospitalization rates for pneumonia and influenza were twice as high in the influenza seasons as they were in the interim (noninfluenza) periods. Influenza vaccination was associated with fewer hospitalizations for pneumonia and influenza (adjusted risk ratio, 0.48 [95% CI, 0.28 to 0.82]) and with lower risk for death (adjusted odds ratio, 0.30 [CI, 0.21 to 0.43]) during the influenza seasons. It was also associated with fewer outpatient visits for pneumonia and influenza and for all respiratory conditions. CONCLUSIONS: For elderly persons with chronic lung disease, influenza is associated with significant adverse health effects and influenza vaccination is associated with substantial health benefits, including fewer outpatient visits, fewer hospitalizations, and fewer deaths. Health care providers should take advantage of all opportunities to immunize these high-risk patients.     

Knowledge,attitude, and practices about the seasonal influenza vaccination among healthcare workers in Srinagar,India

Please cite this paper as: Bali NK et al. (2012) Knowledge, attitude, and practices about the seasonal influenza vaccination among healthcare workers in Srinagar, India. Influenza and Other Respiratory Viruses 7(4), 540–545. Background Healthcare workers (HCWs) universally have a poor uptake of influenza vaccination. However, no data are available from India. Objective To explore knowledge, attitudes, and practices associated with influenza vaccination in HCWs in a temperate climate area in northern India. Patients and Methods A self‐administered questionnaire was offered to all HCWs in three major hospitals of Srinagar and information sought on motivations, perceptions, preferences and practices regarding influenza vaccination. Results Of the 1750 questionnaires received, 1421 (81%) were returned. Only 62 (4·4%) HCWs had ever received influenza vaccination even as 1348 (95%) believed that influenza poses adverse potential consequences for themselves or their contacts; 1144 (81%) were aware of a vaccine against influenza and 830 (58%) of its local availability. Reasons cited by 1359 participants for not being vaccinated included ignorance about vaccine availability (435; 32%), skepticism about efficacy (248; 18%), busy schedule (166; 12%), fear of side effects (70; 4%), and a perception of not being‐at‐risk (82; 6%). Sixty‐one percent (865) believed that vaccine programs are motivated by profit. Eighty‐eight percent opined for mandatory vaccination for HCWs caring for the high‐risk patients, as a part of ‘employee health program’. Most of the participants intended to get vaccinated in the current year even as 684 (48%) held that vaccines could cause unknown illness and 444 (31%) believed their adverse effects to be underreported. Conclusion Influenza vaccination coverage among HCWs is dismally low in Srinagar; poor knowledge of vaccine availability and misperceptions about vaccine effectiveness, fear of adverse effects and obliviousness to being‐at‐risk being important barriers. Multifaceted, adaptable measures need to be invoked urgently to increase the coverage.     

Influenza vaccine coverage for healthcare workers in geriatric settings in France

BACKGROUND AND AIMS: Because of a relative lack of efficiency of influenza vaccine in the elderly population, influenza outbreaks in geriatric healthcare settings are probable, despite high influenza vaccination rates in patients. Nosocomial influenza outbreaks, more probably related to healthcare workers, have also been reported. Therefore, vaccination of healthcare workers is considered to be an important preventive policy, to decrease the in-hospital influenza burden during the viral circulation period. METHODS: This multicenter study measured influenza vaccine coverage of Health Care Worker in 102 geriatric healthcare settings (acute care, rehabilitation care, long-term care) by a first questionnaire. A second questionnaire assessed main factors associated with vaccine acceptance. RESULTS: 102 geriatric healthcare settings (20%) answered the first questionnaire. Vaccine coverage for physicians (n=187), nurses (n=631) and nurse assistants (n=1487) were 48.4%, 30.5% and 27.9%, respectively. Vaccination rates were correlated between occupational categories according to healthcare settings. Vaccination rates were significantly lower in acute care settings compared with rehabilitation and long-term care settings. Local recommendations was reported for 29.9%, but was not correlated with vaccine coverage. The second questionnaire showed that lack of motivation and knowledge, and organizational problems were the three main reasons for reluctance to be vaccinated. CONCLUSIONS: In French geriatric settings, influenza vaccine coverage of healthcare workers is low and highly variable, according to the type of healthcare setting. A group effect was found between occupational categories. However, the reasons for non-acceptance need further evaluation to improve HCW influenza vaccine coverage.     

Influenza vaccination coverage among adults by nativity,race/ethnicity,citizenship, and language of the interview - United States, 2012-2013 through 2017-2018 influenza seasons

BackgroundApproximately 20,000 people died from influenza in the US in the 2019-2020 season. The best way to prevent influenza is to receive the influenza vaccine. Persons who are foreign-born experience disparities in access to, and utilization of, preventative healthcare, including vaccination.MethodsNational Health Interview Survey data were analyzed to assess differences in influenza vaccination coverage during the 2012-2013 through 2017-2018 influenza seasons among adults by nativity, citizenship status of foreign-born persons, race/ethnicity, and language of the interview.ResultsInfluenza vaccination coverage increased significantly during the study period for US-born adults but did not change significantly among foreign-born racial/ethnic groups except for increases among foreign-born Hispanic adults. Coverage for foreign-born adults, those who completed an interview in a non-English language, and non-US citizens, had lower vaccination coverage during most influenza seasons studied, compared with US-born, English-interviewed, and US-citizen adults, respectively.ConclusionsStrategies to improve influenza vaccination uptake must consider foreign-born adults as an underserved population in need of focused, culturally-tailored outreach. Achieving high influenza vaccination coverage among the foreign-born population will help reduce illness among the essential workforce, achieve national vaccination goals, and reduce racial and ethnic disparities in vaccination coverage in the US.     

Influenza Vaccination in Adults with Asthma: Safety of an Inactivated Trivalent Influenza Vaccine

Despite recommendations in most countries for giving inactivated influenza vaccine to people with asthma, only a minority currently receive it. One reason for low vaccine coverage has been concern that vaccination may induce exacerbations of asthma. In this randomized trial, 291 patients between 18 and 65 years of age received either an inactivated influenza vaccine followed 14 days later by a saline placebo or placebo followed by the vaccine. Each patient received 1 dose of vaccine and 1 dose of placebo. The percentage of patients reporting at least one asthma exacerbation within 14 days after injection was similar following vaccine or placebo (28.3% and 25.5%, respectively). The combined exacerbation rate during the first 14-day interval was higher (31.5%) than that during the second 14-day interval (22.4%, P = 0.0135), indicating that the occurrence of exacerbations was not likely to be related to the sequence of injections. The percentages of individuals with solicited systemic symptoms were 56.6% and 44.8% after vaccine or placebo injection, respectively. We conclude that influenza vaccination did not increase the incidence of asthma exacerbations compared to placebo in this study and the vaccine was well tolerated. The results thus support annual influenza vaccination in patients with asthma.     

Influenza Vaccination in Adults with Asthma: Safety of an Inactivated Trivalent Influenza Vaccine

Despite recommendations in most countries for giving inactivated influenza vaccine to people with asthma, only a minority currently receive it. One reason for low vaccine coverage has been concern that vaccination may induce exacerbations of asthma. In this randomized trial, 291 patients between 18 and 65 years of age received either an inactivated influenza vaccine followed 14 days later by a saline placebo or placebo followed by the vaccine. Each patient received 1 dose of vaccine and 1 dose of placebo. The percentage of patients reporting at least one asthma exacerbation within 14 days after injection was similar following vaccine or placebo (28.3% and 25.5%, respectively). The combined exacerbation rate during the first 14-day interval was higher (31.5%) than that during the second 14-day interval (22.4%, P = 0.0135), indicating that the occurrence of exacerbations was not likely to be related to the sequence of injections. The percentages of individuals with solicited systemic symptoms were 56.6% and 44.8% after vaccine or placebo injection, respectively. We conclude that influenza vaccination did not increase the incidence of asthma exacerbations compared to placebo in this study and the vaccine was well tolerated. The results thus support annual influenza vaccination in patients with asthma.