Injection Of Influenza Vaccine Research Articles

COVID-19 infection following influenza vaccine injection and its complications among nurses working in educational-medical hospitals of Ardabil in 2020.

Health care workers are one of the groups at risk of influenza. Currently, influenza vaccination is very important more than ever before. Influenza is evolutionarily similar to SARS-CoV-2, and they have some common epitopes and mechanisms. Thus reducing the severity of COVID-19 disease by influenza vaccination seems possible. Therefore, the aim of this study is to investigate the relationship between influenza vaccination and COVID-19 infection among clinical nurses. The present study is a prospective analysis of nurses working in educational-medical hospitals of Ardabil. In this study, two groups of nurses were considered as case and control groups. The collected data were analyzed using SPSS software and descriptive (mean, standard deviation and frequency) and analytical (Chi-square) tests. A total of 279 individuals were included in the study according to the research criteria. The maximum duration of the disease was one week in the control group and four weeks in the case group. Chi-square test showed that there was a significant difference in terms of disease duration between the two groups (P = 0.000). Chi-square test showed that there was a statistically significant difference in terms of disease treatment between the two groups (P = 0.000). Influenza vaccine reduces the incidence of COVID-19 and reduces the need for hospitalization in patients with this disease. However, due to the positive effects of influenza vaccine on COVID-19 and its low cost, it is recommended to inject influenza vaccine more than before.

Self-care behaviors and related factors in cardiovascular patients: A cross-sectional study

This study was conducted to investigate self-care behaviors and related factors in cardiovascular patients. This cross-sectional study was conducted to determine the self-care behaviors of patients with cardiovascular diseases in the heart center of Mazandaran province in 2015. The data collection tool was a two-part questionnaire. The first part of the questionnaire was demographic information (age, sex, level of education, duration of hospitalization, occupation, disease diagnosis, hospitalization department, and marital status). The second part included a 12-question European Heart Failure Self Care Behavior questionnaire, each item of which is graded from 1 to 5 based on a Likert scale. A total of 268 cardiovascular patients participated in this study. The mean age of patients was 58.37 (SD=11.95). Among the participants, 52.61% were male, 86.19% were married, and 65.67% were literate. Hypertension was present in 52.61% of them and the average duration of cardiovascular disease in them was 5.10 (SD=4.39). The mean of self-care was 29.00 (SD=6.76). 141 people (52.61%) had good self-care behaviors, 121 people (45.15%) had moderate self-care behaviors, and 6 people (2.24%) had poor self-care behaviors. In the context of the relationship between demographic variables and self-care behaviors, no statistically significant relationship was observed (P>0.05). The most self-care behaviors were related to going to the doctor or health centers in case of shortness of breath, taking medicines as recommended by the doctor, allocating enough time to rest, and the least self-care behaviors were related to regular exercise, influenza vaccine injection, and easy handling in case of shortness of breath. Therefore, teaching patients about the importance and how to perform self-care behaviors is very effective in promoting these behaviors and as a result, reducing mortality and hospitalization costs, and nurses play an important role in teaching these behaviors.

Evaluation of Health Promoting Behaviors and Its Relationship with Mental Health in Elderly Military Veterans in Iran

Background: One of the effective factors in the healthy living of the elderly is health-promoting behaviors. Objectives: This study aimed to investigate the relationship between health-promoting behaviors and mental health in elderly military veterans in Iran. Methods: Using available sampling method, this descriptive-analytical study was performed on 280 elderly military veterans over 60 years old referred to a military health center in Urmia, Iran. We used a questionnaire comprising three sections as follows: (1) elderly demographic information; (2) health promoting behaviors; and (3) mental health assessment. The collected data were entered into SPSS software v.20 and analyzed by chi-square and Fisher’s exact tests. Results: The results showed that among the health-promoting behaviors, non-consumption of alcohol, controlling blood pressure, and not smoking had the highest frequency, and the injection of influenza vaccine had the lowest frequency. The relationship between health-promoting behaviors and the level of mental health showed that smoking, stress, alcohol consumption, and not exercising had a significant relationship with anxiety and stress (P < 0.05). Also, the individuals who consumed more fruits and vegetables had less stress than those who consume lower amounts of these foods (P < 0.05). Also, people who consumed low-salt, low-fat, and dairy-based foods, controlled their blood pressure regularly and had received the flu vaccine had a better mental health. Conclusions: According to the results, a special attention should be paid to these factors in planning to teach health-promoting behaviors to improve health and counseling services in the elderly.

Notes from the Field: Administration of Expired Injectable Influenza Vaccines Reported to the Vaccine Adverse Event Reporting System — United States, July 2018–March 2019

During July 11, 2018–March 29, 2019, in the United States, the Vaccine Adverse Event Reporting System received 125 reports of 192 patients receiving expired inactivated influenza vaccine during the 2018–19 influenza season.

Needle-free delivery of influenza vaccine using the Med-Jet® H4 is efficient and elicits the same humoral and cellular responses as standard IM injection: A randomized trial

BackgroundNeedle-free vaccine delivery systems have many potential advantages including increased vaccine compliance and decreased risk of needlestick injuries and syringe reuse. The Med-Jet® H4 is a gas-powered, auto-disabling disposable syringe jet injector. The Med-Jet family of products are currently being used in dermatology, podiatry, pain management and veterinary practices. The objectives of this study were to assess patient attitudes, time-efficiency, safety and immunogenicity of the seasonal influenza vaccine delivered by Med-Jet compared to the traditional needle-and-syringe. MethodsA total of 80 patients were randomized 2:1:1 to receive a commercial trivalent vaccine by Med-Jet or needle injection from a single-dose or multi-dose vial. Patient attitudes were assessed pre-randomization and post-immunization. Safety data were collected for 21 days post-immunization. Efficiency of vaccine administration was measured through a time-and-motion study. Humoral and cellular responses were assessed on Days 0 and 21. ResultsOverall, the participants readily accepted Med-Jet vaccination despite greater frequency of transient local reactions (eg: redness, swelling) immediately following immunization. Vaccine administration took slightly longer with the Med-Jet, but this difference decreased over time. Geometric mean hemagglutination inhibition titers, seroconversion and seroprotection rates in the Med-Jet and needle groups were equivalent for all influenza strains in the vaccine. Microneutralization responses were also essentially identical. There were no significant differences between the groups in the frequency of functional CD4 + T cells, memory subset distribution or poly-functionality. ConclusionsThese data suggest that the Med-Jet is an acceptable means of delivering seasonal influenza vaccine. The system was attractive to subjects, rapidly learned by skilled vaccine nurses and elicited both humoral and cellular responses that were indistinguishable from those elicited with needle injection. While other studies have assessed the humoral response to jet injection of influenza vaccine, to our knowledge, this study is the first to assess the cellular aspect of this response. (ClinTrials.gov-NCT03150537).

2554. Safety and Immunogenicity of NasoVAX, a Novel Intranasal Influenza Vaccine

BackgroundNasoVAX is a replication-deficient adenovirus-based vaccine designed to express influenza hemagglutinin in nasal epithelial cells when given as a nasal spray. In preclinical studies, NasoVAX was associated with divergent strain protection. Prior preclinical and clinical studies with the vector demonstrated lack of impact from baseline adenovirus immunity.MethodsSixty healthy adults were randomized to an A/California 2009-based monovalent NasoVAX formulation at doses of 109, 1010, or 1011 viral particles or saline placebo, all given as a 0.25 mL nasal spray in each nostril. Subjects were followed for safety, including solicited local and systemic side effects. Immune measures included hemagglutination inhibition (HAI) and neutralizing antibody (MN) at days 1, 15, 29, 90, and 180, and γ-interferon ELISpot at day 1 and 8. A parallel cohort of 20 similar subjects were dosed with Fluzone® injectable influenza vaccine containing an A/California 2009 component and had assessments at the same timepoints. The laboratory was blind to treatment assignment for these comparator samples.ResultsNasoVAX was well tolerated with no serious adverse events and no fever. Solicited symptoms such as nasal congestion, sore throat, and headache did not increase with dose and were not statistically different than placebo. Available immune response data are shown below.GroupNasoVAX (109 vp)NasoVAX (1010 vp)NasoVAX (1011 vp)Fluzone®PlaceboSeroprotection Rate at Day 29 (≥1:40 HAI)80%100%100%95%53%(95% CIs)(51.9%, 95.7%)(78.2%, 100.0%)(78.2%, 100.0%)(75.1%, 99.9%)(26.6%, 78.7%)MN Responder Rate at Day 29 (2-fold rise)40%47%73%70%0%(95% CIs)(16.3%, 67.7%)(21.3%, 73.4%)(44.9%, 92.2%)(45.7%, 88.1%)(0.0%, 21.8%)Median ELISpot Day 8 SFC/106 PBMC58.012.0307.555.50.0(95% CIs)(5.31, 110.69)(0.0, 60.36)(2.15, 612.78)(4.12, 106.87)(0.0, 38.49)ConclusionNasoVAX intranasal influenza vaccine was well tolerated and elicited comparable antibody responses and nearly 6-fold higher cellular immune responses than a licensed injectable vaccine.Disclosures S. Tasker, Altimmune, Inc: Employee and Shareholder, Salary. V. Krishnan, Altimmune, Inc.: Employee and Shareholder, Salary. S. Bart, Altimmune, Inc.: Research Contractor, fee for research services. A. Suyundikov, Altimmune, Inc.: Employee, Salary. P. G. Booth, Altimmune, Inc.: Research Contractor, fee for research services. A. Wight O’Rourke, Altimmune, Inc.: Employee and Shareholder, Salary. J. Zhang, Altimmune, Inc.: Employee and Shareholder, Salary. B. Georges, Altimmune, Inc.: Employee and Shareholder, Salary. S. Roberts, Altimmune, Inc.: Employee and Shareholder, Salary.

IgA polymerization contributes to efficient virus neutralization on human upper respiratory mucosa after intranasal inactivated influenza vaccine administration

ABSTRACTUnlike the current injectable influenza vaccines, intranasally administered influenza vaccines induce influenza virus-specific IgA antibodies in the local respiratory mucosa as well as IgG antibodies in the systemic circulation. Our previous study showed that after five volunteers underwent intranasal administration with inactivated H3N2 or H5N1 vaccines, their IgA antibodies on the upper respiratory tract were present as monomers, dimers, and multimers (trimers and tetramers). Moreover, the multimers associated with the highest virus neutralizing activity. However, it has remained elusive whether a more practical intranasal vaccination strategy could induce the high-performance IgA multimers in the nasal mucosa. In the present study, volunteers were administered with two doses of the intranasal trivalent whole-virus inactivated influenza vaccine and showed that in nasal wash samples the amount of multimeric IgA correlated positively with virus neutralizing titers, indicating that the multimeric IgA antibodies play an important role in the antiviral activity at the nasal mucosa. Surface plasmon resonance analysis of the binding dynamics of nasal wash derived IgA monomers, dimers, and multimers against recombinant trimeric influenza virus HA showed that sample fractions containing IgA multimers dissociated from HA less well than sample fractions without IgA multimers. Thus, IgA multimers may “stick” to the antigen more tightly than the other structures. In summary, intranasal administration of two doses of multivalent inactivated influenza vaccines induced multimeric IgA. Multimerization of mucosal IgA antibodies conferred higher neutralizing activity against viruses in the nasal mucosa, possibly by increasing their cohesion to virus antigens.

Frequency and Cost of Vaccinations Administered Outside Minimum and Maximum Recommended Ages—2014 Data From 6 Sentinel Sites of Immunization Information Systems

To quantify vaccinations administered outside minimum and maximum recommended ages and to determine attendant costs of revaccination by analyzing immunization information system (IIS) records. We analyzed deidentified records of doses administered during 2014 to persons aged <18 years within 6 IIS sentinel sites (10% of the US population). We quantified doses administered outside of recommended ages according to the Advisory Committee on Immunization Practices childhood immunization schedule and prescribing information in package inserts, and calculated revaccination costs. To minimize misreporting bias, we analyzed publicly funded doses for which reported lot numbers and vaccine types were consistent. Among 3 394 047 doses with maximum age recommendations, 9755 (0.3%) were given after the maximum age. One type of maximum age violation required revaccination: 1344 (0.7%) of 194 934 doses of the 0.25-mL prefilled syringe formulation of quadrivalent inactivated influenza vaccine (Fluzone Quadrivalent, Sanofi Pasteur, Swiftwater, PA) were administered at age ≥36 months (revaccination cost, $111 964). We identified a total of 7 529 165 childhood, adolescent, and lifespan doses with minimum age recommendations, 9542 of which (0.1%) were administered before the minimum age. The most common among these violations were quadrivalent injectable influenza vaccines (3835, or 0.7% of 526 110 doses administered before age 36 months) and Kinrix (GlaxoSmithKline Biologicals, Rixensart, Belgium; DTaP-IPV) (2509, or 1.2% of 208 218 doses administered before age 48 months). The cost of revaccination for minimum age violations (where recommended) was $179 179. Administration of vaccines outside recommended minimum and maximum ages is rare, reflecting a general adherence to recommendations. Error rates were higher for several vaccines, some requiring revaccination. Vaccine schedule complexity and confusion among similar products might contribute to errors. Minimization of errors reduces wastage, excess cost, and inconvenience for parents and patients.

School-located Influenza Vaccinations for Adolescents: A Randomized Controlled Trial

PurposeWe aimed to evaluate the effect of school-located influenza vaccination (SLIV) on adolescents' influenza vaccination rates. MethodsIn 2015–2016, we performed a cluster-randomized trial of adolescent SLIV in middle/high schools. We selected 10 pairs of schools (identical grades within pairs) and randomly allocated schools within pairs to SLIV or usual care control. At eight suburban SLIV schools, we sent parents e-mail notifications about upcoming SLIV clinics and promoted online immunization consent. At two urban SLIV schools, we sent parents (via student backpack fliers) paper immunization consent forms and information about SLIV. E-mails were unavailable at these schools. Local health department nurses administered nasal or injectable influenza vaccine at dedicated SLIV clinics and billed insurers. We compared influenza vaccination rates at SLIV versus control schools using school directories to identify the student sample in each school. We used the state immunization registry to determine receipt of influenza vaccination. ResultsThe final sample comprised 17,650 students enrolled in the 20 schools. Adolescents at suburban SLIV schools had higher overall influenza vaccination rates than did adolescents at control schools (51% vs. 46%, p < .001; adjusted odds ratio = 1.27, 95% confidence interval 1.18–1.38, controlling for vaccination during the prior two seasons). No effect of SLIV was noted among urbanschools on multivariate analysis. SLIV did not substitute for vaccinations in primary care or other settings; in suburban settings, SLIV was associated with increased vaccinations in primary care or other settings (adjusted odds ratio = 1.10, 95% confidence interval 1.02–1.19). ConclusionsSLIV in this community increased influenza vaccination rates among adolescents attending suburban schools.

Changes in Influenza Vaccination Rates After Withdrawal of Live Vaccine.

Before the start of the 2016-2017 influenza season, the Advisory Committee on Immunization Practices withdrew its recommendation promoting the use of live attenuated influenza vaccines (LAIVs). There was concern that this might lessen the likelihood that those with a previous LAIV would return for an injectable influenza vaccine (IIV) and that child influenza immunization rates would decrease overall. Using Oregon's statewide immunization registry, the ALERT Immunization Information System, child influenza immunization rates were compared across the 2012-2013 through 2016-2017 seasons. Additionally, matched cohorts of children were selected based on receipt of either an LAIV or an IIV during the 2015-2016 season. Differences between the IIV and LAIV cohorts in returning for the IIV in the 2016-2017 season were assessed. Overall, influenza immunization rates for children aged 2 to 17 years were unchanged between the 2015-2016 and 2016-2017 seasons. Children aged 3 to 10 with a previous IIV were 1.03 (95% confidence interval, 1.02 to 1.04) times more likely to return for an IIV in 2016-2017 than those with a previous LAIV, whereas children aged 11 to 17 years with a previous IIV were 1.08 (95% confidence interval, 1.05 to -1.09) times more likely to return. Withdrawal of the LAIV recommendation was not associated with an overall change in child influenza immunization rates across seasons. Children with a previous (2015-2016) IIV were slightly more likely to return during the 2016-2017 season for influenza immunization than those with a previous LAIV.

Improving influenza vaccination in chronically ill children using a tertiary-care based vaccination clinic: Is there a role for the live-attenuated influenza vaccine (LAIV)?

BackgroundChildren with underlying medical conditions should receive influenza vaccine (IV) yearly; yet this remains sub-optimal. We aimed to describe our experience with a tertiary-care hospital-based influenza vaccination clinic for this at-risk population. MethodsFrom October to December 2012, 2013, and 2014, we ran an influenza vaccination clinic at the Montreal Children's Hospital, where children with high-risk conditions come for their follow-up. Both injectable IV (IIV) and live-attenuated IV (LAIV) were offered free of charge to patients and their household contacts. Upon vaccination, parents were asked to fill a pre-piloted questionnaire. ResultsWe vaccinated a total of 2640 high-risk children and 1912 household members during the three influenza vaccination seasons. In 2012 and 2013, 631 and 630 patients with chronic illnesses were vaccinated, compared to 1379 in 2014. Caregivers preferred LAIV primarily because no needle was involved (49.0%) and because it was perceived as less painful (46.9%). LAIV was administered to 69% (2012), 55% (2013) and 47% (2014) of high-risk children. The main reason for not receiving LAIV was because it was contra-indicated. A small fraction of children previously vaccinated with LAIV who did not present any contraindication to LAIV opted for IIV: 12/101 (11.8%) in 2013 and 16/272 (5.9%) in 2014. In 2014, this was mainly due to a previous negative experience with LAIV (11/16). ConclusionHaving an influenza vaccination clinic on site at a tertiary care hospital, where children come for their scheduled visits, facilitates yearly influenza vaccination in children with chronic illnesses. LAIV is preferred by caregivers and patients, when not contraindicated.

Vaccine allergies

Currently, the increasing numbers of vaccine administrations are associated with increased reports of adverse vaccine reactions. Whilst the general adverse reactions including allergic reactions caused by the vaccine itself or the vaccine components, are rare, they can in some circumstances be serious and even fatal. In accordance with many IgE-mediated reactions and immediate-type allergic reactions, the primary allergens are proteins. The proteins most often implicated in vaccine allergies are egg and gelatin, with perhaps rare reactions to yeast or latex. Numerous studies have demonstrated that the injectable influenza vaccine can be safely administered, although with appropriate precautions, to patients with severe egg allergy, as the current influenza vaccines contain small trace amounts of egg protein. If an allergy is suspected, an accurate examination followed by algorithms is vital for correct diagnosis, treatment and decision regarding re-vaccination in patients with immediate-type reactions to vaccines. Facilities and health care professionals should be available to treat immediate hypersensitivity reactions (anaphylaxis) in all settings where vaccines are administered.

Development of a nanoparticle-based influenza vaccine using the PRINT® technology

Historically it is known that presentation of vaccine antigens in particulate form, for a wide range of pathogens, has clear advantages over the presentation of soluble antigen alone [J.C. Aguilar, E.G. Rodriguez, Vaccine adjuvants revisited. Vaccine 25 (2007) 3752–3762, M. Singh, D. O'Hagan, Advances in vaccine adjuvants. Nature Biotechnology 17 (1999) 1075–1081]. Herein we describe a novel particle-based approach, which independently controls size, shape, and composition to control the delivery and presentation of vaccine antigen to the immune system. Highly uniform particles were produced using a particle molding technology called PRINT® (Particle Replication in Non-wetting Templates) which is an off-shoot of imprint lithography [J Am Chem Soc 127 (2005) 10096–10100, J Am Chem Soc 126 (2004) 2322–2323, Chem Soc Rev 35 (2006) 1095–1104, J Am Chem Soc 130 (2008) 5008–5009, J Am Chem Soc 130 (2008) 5438–5439, Polymer Reviews 47 (2007) 321–327, Acc Chem Res 41 (2008) 1685–1695, Acc Chem Res 44 (10) (2011) 990–998]. Cylindrical (diameter [d]=80nm, height [h]=320nm) poly (lactide-co-glycolide) (PLGA) based PRINT particles were designed to electrostatically bind commercial trivalent injectable influenza vaccine. In a variety of blended PLGA formulations, these particles were safe and showed enhanced responses to influenza hemagglutinin in murine models. From the Clinical EditorShape is one of the determining factors in interactions of nanoparticles with their biologic environment. PRINT technology is able to fabricate nearly uniform nanoparticles and this technology is tested here in murine models to effectively deliver influenza vaccine.

A "Needling" Problem: Shoulder Injury Related to Vaccine Administration

A 22-year-old woman with no significant medical history developed acute left shoulder pain and severe restrictions in range of motion after a seasonal influenza vaccine injection. Imaging by MRI, approximately 8 weeks after the injection, and by ultrasound, approximately 9.5 weeks after the injection demonstrated contusions on the humerus, injury of the supraspinatus, and effusion in the subacromial bursa. Her reaction was reported to the Vaccine Adverse Event Reporting System as a case of shoulder injury related to vaccine administration, likely due to injection of the influenza vaccine into the subacromial bursa. This case serves as a catalyst for discussion regarding vaccination technique and the potential to prevent complications arising from vaccine overpenetration.

Influenza vaccine-related information needs of US primary care physicians

Objective To explore influenza-related information needs of primary care providers, given expanded influenza vaccine recommendations and new influenza vaccine products. Methods A cross-sectional, mailed survey of a national sample of primary care physicians (family physicians, general internists, pediatricians), conducted in July–October 2010. The overall response rate was 70%. Results Among respondents who offer immunizations, almost all expected to provide injectable influenza vaccine for the 2010–11 influenza season, while only pediatricians planned wide use of intranasal vaccine. The information needs most frequently rated as high priority were subpopulations to prioritize if vaccine supply is limited and use of a higher dose formulation for the elderly. Most physicians who do not currently use intranasal vaccine rated that topic as a low priority. Conclusion Primary care providers have a number of high-priority information needs related to influenza vaccination. However, the limited interest of family physicians and internists in receiving more information about intranasal vaccine may impede efforts to expand its use among healthy adults.

Extranodal MALT Lymphoma of the Right Triceps Muscle following Influenza Vaccine Injection: A Rare Case with an Interesting Presentation

The study describes a case of a 67-year-old female who developed a Stage I E marginal zone lymphoma of the right triceps muscle 1 month after influenza vaccination at the same site. She was treated with single modality, involved field radiation therapy (IFRT) to 4000 cGy in 20 fractions with excellent response and no evidence of disease after one year followup.

Single-dose influenza vaccination of patients with egg allergy in a multicenter study

Single-dose influenza vaccination of patients with egg allergy in a multicenter study

Vaccine presentation in the USA: economics of prefilled syringes versus multidose vials for influenza vaccination

In the USA, influenza vaccines are available as parenteral injections or as an intranasal preparation. Injectable influenza vaccines are available in either multidose vial (MDV), single-dose vial or prefilled syringe (PFS) presentations. PFSs have gained market share in the USA but have not yet reached the levels of uptake currently seen in Western Europe. Here, we review the topic of vaccine presentation in the USA, with a special focus on influenza vaccines. Second, we present the results of a time-motion study that measured administration costs of influenza vaccination comparing MDVs versus PFSs during the 2009/2010 influenza campaign. Vaccinating with MDVs took an average 37.3 s longer than PFSs. The cost of administering 1000 immunizations in 2009 using MDVs were US$8596 versus US$8920.21 using PFSs. In a pandemic situation where 300 million Americans would require vaccination, PFSs would save 3.12 million h in healthcare worker time, worth US$111.1 million. The higher acquisition costs of PFS vaccines compared with MDVs are offset by lower administrative costs and increased safety.

Serum Antibody Responses after Intradermal Injection of Influenza Vaccine*

Serum Antibody Responses after Intradermal Injection of Influenza Vaccine*

Impact of the 2004–2005 Influenza Vaccine Shortage on Pediatric Practice: A National Survey

A severe influenza vaccine shortage occurred during the 2004-2005 influenza season because of the loss of all vaccine made by Chiron (Emeryville, CA) for US distribution. The objectives of this study were to assess among pediatricians nationally: (1) influenza vaccine-delivery strategies; (2) reported vaccine shortages and factors associated with experiencing shortages; and (3) the impact of shortages on vaccine redistribution, patient referral, and clinical practice, including patient prioritization. A survey was administered in March 2005 through June 2005 to 427 pediatricians who participated in a national network representative of the American Academy of Pediatrics membership. RESULTS. Our response rate was 82%. Thirty-nine percent of the pediatricians had a computerized method for identifying patients at high risk needing vaccination. Ninety-four percent and 79% reported giving high-priority to children >/=24 months old with high-risk conditions and children 6 to 23 months old, respectively, whereas 41% gave high-priority to household contacts and caregivers of children <6 months old. Forty-three percent reported experiencing shortages of vaccine for patients at high risk, whereas only 14% ordered Chiron vaccine. In multivariate analyses, ordering vaccine from Chiron and ordering Aventis Pasteur (Lyon, France) vaccine solely from a vaccine distributor were associated with experiencing a shortage. Forty-eight percent of respondents obtained additional vaccine from another source, most frequently the public health sector, whereas 37% reported selling or giving away vaccine. In addition, 47% referred patients at high risk elsewhere for vaccination, primarily to public health clinics. Forty-nine percent reported having unused vaccine remaining at the end of the season. Although few pediatricians ordered Chiron vaccine, substantial influenza vaccine shortages were reported, highlighting the tenuousness of injectable influenza vaccine supplies for children. The extensive redistribution of vaccine suggests that cooperative efforts between the private and public sectors were widespread. Efforts to vaccinate patients at high risk during shortages would be aided by better systems to identify and recall these patients.