Influenza Vaccine In Children Research Articles

Safety, immunogenicity, and lot-to-lot consistency of a quadrivalent inactivated influenza vaccine in children, adolescents, and adults: A randomized, controlled, phase III trial

BackgroundInactivated quadrivalent influenza vaccine (IIV4) containing two influenza A strains and one strain from each B lineage (Yamagata and Victoria) may offer broader protection against seasonal influenza than inactivated trivalent influenza vaccine (IIV3), containing a single B strain. This study examined the safety, immunogenicity, and lot consistency of an IIV4 candidate. MethodsThis phase III, randomized, controlled, multicenter trial in children/adolescents (9 through 17 years) and adults (18 through 60 years) was conducted in Australia and in the Philippines in 2012. The study was double-blind for IIV4 lots and open-label for IIV4 vs IIV3. Children/adolescents were randomized 2:2:2:1 and adults 10:10:10:1 to receive one of three lots of IIV4 or licensed IIV3. Safety data were collected for up to 6 months post-vaccination. Hemagglutination inhibition and seroneutralization antibody titers were assessed pre-vaccination and 21 days post-vaccination. Results1648 adults and 329 children/adolescents received IIV4, and 56 adults and 55 children/adolescents received IIV3. Solicited reactions, unsolicited adverse events, and serious adverse events were similar for IIV3 and IIV4 recipients in both age groups. Injection-site pain, headache, malaise, and myalgia were the most frequently reported solicited reactions, most of which were mild and resolved within 3 days. No vaccine-related serious adverse events or deaths were reported. Post-vaccination antibody responses, seroconversion rates, and seroprotection rates for the 3 strains common to both vaccines were comparable for IIV3 and IIV4 in both age groups. Antibody responses to IIV4 were equivalent among vaccine lots and comparable between age groups for each of the 4 strains. IIV4 met all European Medicines Agency immunogenicity criteria for adults for all 4 strains. ConclusionsIn both age groups, IIV4 was well tolerated and caused no safety concerns, induced robust antibody responses to all 4 influenza strains, and met all EMA immunogenicity criteria for adults. Clinical trial registry numberNCT01481454.

Impacting delayed pediatric influenza vaccination: a randomized controlled trial of text message reminders.

Influenza vaccination coverage is low, especially among low-income populations. Most doses are generally administered early in the influenza season, yet sustained vaccination efforts are crucial for achieving optimal coverage. The impact of text message influenza vaccination reminders was recently demonstrated in a low-income population. Little is known about their effect on children with delayed influenza vaccination or the most effective message type. To determine the impact of educational plus interactive text message reminders on influenza vaccination of urban low-income children unvaccinated by late fall. Randomized controlled trial. Parents of 5,462 children aged 6 months-17 years from four academically affiliated pediatric clinics who were unvaccinated by mid-November 2011. Eligible parents were stratified by their child's age and pediatric clinic site and randomized using a 1:1:1 allocation to educational plus interactive text message reminders, educational-only text message reminders, or usual care. Using an immunization registry-linked text messaging system, parents of intervention children received up to seven weekly text message reminders. One of the messages sent to parents in the educational plus interactive text message arm allowed selection of more information about influenza and influenza vaccination. Influenza vaccination by March 31, 2012. Data were collected and analyzed between 2012 and 2014. Most children were publicly insured and Spanish speaking. Baseline demographics were similar between groups. More children of parents in the educational plus interactive text message arm were vaccinated (38.5%) versus those in the educational-only text message (35.3%; difference=3.3%, 95% CI=0.02%, 6.5%; relative risk ratio (RRR)=1.09, 95% CI=1.002, 1.19) and usual care (34.8%; difference=3.8%, 95% CI=0.6%, 7.0%; RRR=1.11, 95% CI=1.02-1.21) arms. Text message reminders with embedded educational information and options for interactivity have a small positive effect on influenza vaccination of urban, low-income, minority children who remain unvaccinated by late fall.

Influenza vaccination in children with neurologic or neurodevelopmental disorders

BackgroundChildren with neurologic or neurodevelopmental disorders (NNDDs) are at increased risk of complications from influenza. Although the Advisory Committee on Immunization Practices (ACIP) has recognized NNDDs as high-risk conditions for influenza complications since 2005, little is known about influenza vaccination practices in this population. MethodsCDC collaborated with Family Voices, a national advocacy group for children with special healthcare needs, to recruit parents of children with chronic medical conditions. Parents were surveyed about their knowledge, attitudes, and practices surrounding influenza vaccination. The primary outcome of interest was parental report of vaccination, or intent to vaccinate, at the time of survey participation. CDC also collaborated with the American Academy of Pediatrics to recruit primary care and specialty physicians who provide care for high-risk children, specifically those with neurologic conditions. The primary outcome was physician recognition of ACIP high-risk influenza conditions. Results2138 surveys were completed by parents of children with high-risk conditions, including 1143 with at least one NNDD. Overall, 50% of children with an NNDD were vaccinated, or their parents planned to have them vaccinated against influenza. Among all 2138 children, in multivariable analysis, the presence of a respiratory condition and prior seasonal influenza vaccination was significantly associated with receipt or planned current season influenza vaccination, but the presence of an NNDD was not. 412 pediatricians completed the provider survey. Cerebral palsy was recognized as a high-risk influenza condition by 74% of physician respondents, but epilepsy (51%) and intellectual disability (46%) were less commonly identified. ConclusionsOur estimates of influenza vaccination in children with NNDDs are comparable to published reports of vaccination in healthy children, which continue to be suboptimal. Education of parents of children with NNDDs and healthcare providers about influenza and the benefit of annual influenza vaccination is needed.

Phased introduction of a universal childhood influenza vaccination programme in England: population-level factors predicting variation in national uptake during the first year, 2013/14

IntroductionThrough a phased rollout, the UK is implementing annual influenza vaccination for all healthy children aged 2–16 years old. In the first year of the programme in England in 2013/14, all 2–3 year olds were offered influenza vaccine through primary care and a primary school age programme was piloted, mainly through schools, in geographically distinct areas. Equitable delivery is a key aim of the programme; it is unclear if concerns by some religious groups over influenza vaccine content have impacted on uptake. MethodsAt the end of the 2013/14 season, variations in uptake for 2–3 year olds and 4–11 year olds were assessed and stratified by population-level predictors: deprivation, ethnicity, religious beliefs and rurality. GP practice or school level uptake was linearly regressed against these variables to determine potential predictors and changes in uptake, adjusting for significant factors. ResultsUptake varied considerably by geographic locality for both 2–3 year olds and 4–11 year olds. Lower uptake was seen in increasingly deprived areas, with an adjusted uptake in the most deprived quintile 12% and 8% lower than the least deprived areas by age-group respectively. By ethnicity, the highest non-white population quartile had an adjusted uptake 9% and 14% lower than the lowest non-white quartile by age-group respectively. Uptake also varied according to religious beliefs, with adjusted uptake in 4–11 year olds in the highest Muslim population tertile 8% lower than the lowest Muslim population tertile. ConclusionIn the first season of the childhood influenza vaccination programme, uptake was not uniform across the country, with deprivation and ethnicity both predictors of low uptake in pre-school and primary school age children, and religious beliefs also an important factor, particularly the latter group. With the continued rollout of the programme, these population-level factors should be addressed to achieve sustained successful uptake, along with assessment of contribution of individual and household-level factors.

Parental vaccine hesitancy and acceptance of seasonal influenza vaccine in the pediatric emergency department

BackgroundProviding influenza vaccine to patients in the pediatric emergency department (PED) is one strategy to increase childhood influenza vaccine uptake. The Parent Attitudes about Childhood Vaccines (PACV) survey is a new tool to identify vaccine-hesitant parents that may facilitate influenza vaccine uptake in the PED. ObjectiveTo assess the feasibility of administering the PACV modified for influenza vaccination in the PED setting and to determine whether parental PACV scores are associated with patient receipt of influenza vaccine in the PED. MethodsWe conducted a cross-sectional study in the PED of a tertiary pediatric hospital in Seattle, WA during the 2013–2014 influenza season. English-speaking parents of children aged 6 months to 7 years who were afebrile, medically stable to be discharged home from the PED, and had not already received an influenza vaccine this season were administered a modified version of the PACV. PACV scores (0–100, higher score=higher hesitancy) were dichotomized (<50 and ≥50) consistent with previous validation studies. Feasibility was assessed by determining time to complete the PACV. Our primary outcome was influenza vaccine refusal in the PED. We used multivariable logistic regression to estimate unadjusted and adjusted odds ratios for association between vaccine refusal and dichotomized PACV scores. Results152 parent participants were included in the analysis. The median time for administering the PACV was 7min. The median PACV score was 28, with 74% scoring <50. Parents who scored ≥50 on the PACV had increased odds of refusing the influenza vaccine compared to parents who scored <50 (adjusted OR [95% CI]: 6.58 [2.03–21.38]). ConclusionAdministration of the PACV in the PED is feasible, and higher PACV scores in this setting are associated with increased influenza vaccine refusal.

Student column: Using academic detailing to improve childhood influenza vaccination rates in San Diego.

Student column: Using academic detailing to improve childhood influenza vaccination rates in San Diego.

Safety of live attenuated influenza vaccine in atopic children with egg allergy

BackgroundLive attenuated influenza vaccine (LAIV) is an intranasal vaccine recently incorporated into the United Kingdom immunization schedule. However, it contains egg protein and, in the absence of safety data, is contraindicated in patients with egg allergy. Furthermore, North American guidelines recommend against its use in asthmatic children.ObjectiveWe sought to assess the safety of LAIV in children with egg allergy.MethodsWe performed a prospective, multicenter, open-label, phase IV intervention study involving 11 secondary/tertiary centers in the United Kingdom. Children with egg allergy (defined as a convincing clinical reaction to egg within the past 12 months and/or >95% likelihood of clinical egg allergy as per published criteria) were recruited. LAIV was administered under medical supervision, with observation for 1 hour and telephone follow-up 72 hours later.ResultsFour hundred thirty-three doses were administered to 282 children with egg allergy (median, 4.9 years; range, 2-17 years); 115 (41%) had experienced prior anaphylaxis to egg. A physician's diagnosis of asthma/recurrent wheezing was noted in 67%, and 51% were receiving regular preventer therapy. There were no systemic allergic reactions (upper 95% CI for population, 1.3%). Eight children experienced mild self-limiting symptoms, which might have been due an IgE-mediated allergic reaction. Twenty-six (9.4%; 95% CI for population, 6.2% to 13.4%) children experienced lower respiratory tract symptoms within 72 hours, including 13 with parent-reported wheeze. None of these episodes required medical intervention beyond routine treatment.ConclusionsIn contrast to current recommendations, LAIV appears to be safe for use in children with egg allergy. Furthermore, the vaccine appears to be well tolerated in children with a diagnosis of asthma or recurrent wheeze.

Effectiveness and safety of live attenuated influenza vaccine in children of 2 to 17 years old

Live attenuated influenza vaccine(LAIV)is a Live attenuated influenza vaccine.LAIV has demonstrated significantly greater protection against influenza in healthy children or children with a history of respiratory diseases or with immunodeficiency diseases 2 to17 years of age as compared with TIV.LAIV can prevent influenza more efficient without increasing hospitalization and emergency department visits as compared with TIV.Except for the runny nose and nasal congestion, no excess risk of adverse events have been found among children who were vaccinated with LAIV compared with those vaccinated with TIV.LAIV has the potential in children to stimulate greater local anti-influenza immune responses and its protective effect can extend beyond the year of administration.Vaccining LAIV is convenient and noninvasive for children, it is easily accepted by children and their parents.LAIV offers a effective approach to prevent influenza. Key words: Influenza vaccines; Live attenuated; Inactivated; Efficacy; Safety; Children

Immunogenicity and safety of cell-derived MF59®-adjuvanted A/H1N1 influenza vaccine for children

Mass immunization of children has the potential to decrease infection rates and prevent the transmission of influenza. We evaluated the immunogenicity, safety, and tolerability of different formulations of cell-derived MF59-adjuvanted and nonadjuvanted A/H1N1 influenza vaccine in children and adolescents. This was a randomized, single-blind, multicenter study with a total of 666 healthy subjects aged 6 months–17 y in one of 3 vaccination groups, each receiving formulations containing different amounts of influenza A/H1N1 antigen with or without MF59. A booster trivalent seasonal MF59 vaccine was administered one year after primary vaccinations. Antibody titers were assessed by hemagglutination inhibition (HI) and microneutralization assays obtained on days 1, 22, 43, 366, and 387 (3 weeks post booster). Safety was monitored throughout the study. One vaccination with 3.75 μg of A/H1N1 antigen formulated with 50% MF59 (3.75_halfMF59) or 7.5 μg of A/H1N1 antigen formulated with 100% MF59 (7.5_fullMF59) induced an HI titer ≥1:40 in >70% of children in the 1–<3, 3–8, and 9–17 y cohorts; however, 2 vaccinations with nonadjuvanted 15 μg A/H1N1 antigen were needed to achieve this response in the 1–<3 and 3–8 y cohorts. Among children aged 6–11 months, 1 dose of 7.5_fullMF59 resulted in an HI titer ≥1:40 in >70% while 2 doses of 3.75_halfMF59 were required to achieve this result. All vaccines were well tolerated. Our findings support the immunogenicity and safety of the 3.75_halfMF59 (2 doses for children <12 months) and 7.5_fullMF59 vaccine formulations for use in children and adolescents aged 6 months to 17 y The use of the 3.75_halfMF59 could have the benefit of antigen and adjuvant sparing, increasing the available vaccine doses allowing vaccination of more people.

Safety of influenza vaccination in children with allergic diseases.

Global guidelines strongly recommend annual influenza vaccination in people age 6 months and older, particularly in asthmatic children. There is no doubt about the benefit of influenza vaccination in asthmatic children. However, some of the vaccine's components may elicit an IgE mediated hypersensitivity or disease exacerbation, including life-threatening events, in children with allergic diseases. As a result, concerns regarding the safety of the vaccine still continue today. The influenza vaccine is grown on hens' eggs and contains a trace of egg protein. Consequently, it can provoke an allergic reaction or anaphylaxis in children with an egg allergy or exacerbation in those with asthma. Therefore, we need to know the risks and benefits of the influenza vaccine and the best strategy for safe vaccination. Although most guidelines have consistently reported the safety of influenza vaccination in children with allergic disease, and have recommended annual administration, safety concerns impede guideline-based performance in practice. The safety and efficacy of influenza vaccination for allergic children are summarized in the present review.

Use of Live Attenuated Influenza Vaccine in Children With Egg Allergy and Asthma

Use of Live Attenuated Influenza Vaccine in Children With Egg Allergy and Asthma

Safety and Effectiveness of a 2009 H1N1 Vaccine in Chronic Kidney Disease Children

Background/Aims: Influenza vaccination is the most effective method for preventing influenza infection and its complications. The risk groups are children with chronic kidney diseases (CKDs) such as children on peritoneal dialysis (PD) and hemodialysis (HD), predialysis CKD (pCKD) and renal transplant (RTx) patients and immunosuppressed children. The aim of the present study was to assess the safety and immunogenicity of a single administration of a monovalent inactivated pandemic (H1N1) 2009 vaccine in children with CKD. Methods: Patients were given a single intramuscular injection of 0.5 ml of monovalent inactivated vaccine. Results: Totally, there were 25 pediatric patients with a diagnosis of CKD (16 PD, 2 HD, 3 pCKD and 4 RTx). Seroconversion was observed in 15 of the 16 patients with PD. Seroconversion occurred in all patients undergoing pCKD and HD. However, 3 of the RTx patients were seronegative. Conclusion: This study demonstrated a high level of immunogenicity and safety of an (H1N1) 2009 influenza vaccine in children with CKD.

Effects of inactivated influenza vaccine on respiratory illnesses and asthma-related events in children with mild persistent asthma in Asia.

Acute asthmatic exacerbation and readmission may be associated with severe influenza infection and asthmatic children are a priority group for influenza vaccination. To date, our study is the first to evaluate the outcome of the influenza vaccine in asthmatic Asian children. To analyze the outcomes of inactivated influenza vaccine in children with mild persistent asthma A cross sectional non-randomized study was performed on 93 mild persistent asthmatic children who attended the Pediatric Allergy clinic between June 2012 in Chiang Rai Hospital and August 2013. Forty eight patients were immunized with 2 doses of inactivated influenza vaccine at one month interval. Respiratory illnesses and asthma-related events were compared between the immunized and the un-immunized groups. The two study groups had similar demographic and clinical characteristic except with regards to eczema, including asthma controllers and skin prick testing results. One year after the vaccine was administered, the immunized group had significantly reduced acute respiratory tract illnesses, asthma exacerbations, ER visits, bronchodilator usage and systemic steroid administrations. Hospitalizations (p < 0.001) and their duration (p < 0.034) were also reduced in the immunized group. Immunization of inactivated influenza vaccine in children with mild persistent asthma decreased respiratory illnesses and asthma-related events.

650Relative Vaccine Effectiveness of Live-Attenuated Versus Inactivated Influenza Vaccines in Children and Adolescents Aged 2–18 Years in Two Seasons – US Flu VE Network

650Relative Vaccine Effectiveness of Live-Attenuated Versus Inactivated Influenza Vaccines in Children and Adolescents Aged 2–18 Years in Two Seasons – US Flu VE Network

Immunogenicity and tolerability of an MF59-adjuvanted, egg-derived, A/H1N1 pandemic influenza vaccine in children 6-35 months of age.

Vaccines against pandemic A/H1N1 influenza should provide protective immunity in children, because they are at greater risk of disease than adults. This study was conducted to identify the optimal dose of an MF59®-adjuvanted, egg-derived, A/H1N1 influenza vaccine for young children. Children 6-11 months (N = 144) and 12-35 months (N = 186) of age received vaccine formulations containing either 3.75 μg antigen with half the standard dose of MF59 or 7.5 μg antigen with a standard dose of MF59, or a nonadjuvanted formulation containing 15 μg antigen (children 12-35 months only). Participants were given 2 primary vaccine doses 3 weeks apart, followed by 1 booster dose of MF59-adjuvanted seasonal influenza vaccine 1 year later. Immunogenicity was assessed by hemagglutination inhibition and microneutralization assays. All vaccine formulations were highly immunogenic and met all 3 European licensure criteria after 2 doses. MF59-adjuvanted vaccines met all licensure criteria after 1 dose in both age cohorts, while nonadjuvanted vaccine did not meet all criteria after 1 dose in children 12-35 months. A single booster dose was highly immunogenic, and stable antibody persistence was observed in response to all vaccines. All vaccines were well tolerated. In this study, a single dose of 3.75 μg antigen with half the standard dose of MF59 was shown to be optimal, providing adequate levels of immediate and long-term antibodies in pediatric subjects 6-35 months of age. These data demonstrated that MF59 adjuvant allowed for reduced antigen content and promoted significant long-term antibody persistence in children, with a satisfactory safety profile.

Increasing the use of influenza vaccines in children with egg allergy

Administration of inactivated trivalent or quadrivalent influenza vaccines is now believed to be safe for individuals with egg allergy. Unless children have experienced an anaphylactic reaction to a previous dose of influenza vaccine, they can and should be immunized with a full dose of trivalent or quadrivalent inactivated vaccine.

Longevity of B-cell and T-cell responses after live attenuated influenza vaccination in children.

Background. The live attenuated influenza vaccine (LAIV) is the preferred vaccine for children, but the mechanisms behind protective immune responses are unclear, and the duration of immunity remains to be elucidated. This study reports on the longevity of B-cell and T-cell responses elicited by the LAIV.Methods. Thirty-eight children (3–17 years old) were administered seasonal LAIV. Blood samples were collected before vaccination with sequential sampling up to 1 year after vaccination. Humoral responses were evaluated by a hemagglutination inhibition assay, and memory B-cell responses were evaluated by an enzyme-linked immunosorbent spot assay (ELISpot). T-cell responses were evaluated by interferon γ (IFN-γ) ELISpot analysis, and intracellular cytokine staining of CD4+ T cells for detection of IFN-γ, interleukin 2, and tumor necrosis factor α was performed using flow cytometry.Results. LAIV induced significant increases in B-cell and T-cell responses, which were sustained at least 1 year after vaccination. Strain variations were observed, in which the B strain elicited stronger responses. IFN-γ–expressing T cell counts increased significantly, and remained higher than prevaccination levels 1 year later. Expression of T-helper type 1 intracellular cytokines (interleukin 2, IFN-γ, and tumor necrosis factor α) increased after 1 dose and were boosted after the second dose. Hemagglutination inhibition titers were sustained for 1 year. Vaccine-induced memory B cell counts were significantly increased, and the response persisted for one year.Conclusions. LAIV elicited B-cell and T-cell responses that persisted for at least 1 year in children. This is a novel finding that will aid future vaccine policy.

Seasonal influenza vaccination rates and reasons for non-vaccination in children with gastrointestinal disorders

ObjectivesDespite advances in the treatment and prevention of influenza, it is still considered an important cause of morbidity and mortality worldwide. Annual vaccination is the safest and most effective mean of prevention. Our study aims were to explore the uptake of influenza vaccination among children with gastrointestinal disorders, and to characterize non-adherent patients. MethodsThe present cross-sectional study included parents of pediatric patients attending the Gastroenterology Institute at Schneider Children's Medical Center of Israel between September and October 2011. Parents were asked to complete a questionnaire concerning demographic and clinical parameters, influenza vaccination of the child, and reasons for not vaccinating the child, when appropriate. ResultsThe study population included 273 patients (50% female), with a median age of 10 years (range, 2–18 years). Overall, the rate of seasonal influenza vaccination was 30.8%. Higher rates were found among immunosuppressed patients (46.1%), and in patients with inflammatory bowel disease (50%). There was no significant effect of patient age, gender, ethnic origin or parental level of education on the vaccination rate. Vaccination rates were significantly associated with parents’ information and knowledge of, as well as their personal beliefs regarding the vaccine (P<0.001). ConclusionsInfluenza vaccination rates are relatively low in the pediatric population attending gastroenterology clinics, in both high- and low-risk groups. The importance of parental knowledge in compliance with influenza vaccination of children should prompt general pediatricians and gastroenterologists to discuss and address the common misconceptions regarding the vaccine.

Safety and immunogenicity of an MF59®-adjuvanted A/H1N1 pandemic influenza vaccine in children from three to seventeen years of age

ObjectivesThis study was designed to identify the optimal dose of an MF59®-adjuvanted, monovalent, A/H1N1 influenza vaccine in healthy paediatric subjects. MethodsSubjects aged 3–8 years (n=194) and 9–17 years (n=160) were randomized to receive two primary doses of A/H1N1 vaccine containing either 3.75μg antigen with half a standard dose of MF59 adjuvant, 7.5μg antigen with a full dose of MF59, or (children 3–8 years only), a non-adjuvanted 15μg formulation. A booster dose of MF59-adjuvanted seasonal influenza vaccine including homologous A/H1N1 strain was given one year after priming. Immunogenicity was assessed by haemagglutination inhibition (HI) and microneutralization assays. Vaccine safety was assessed throughout the study (up to 18 months). ResultsA single priming dose of either MF59-adjuvanted formulation was sufficient to meet the European licensure criteria for pandemic influenza vaccines (HI titres ≥1:40>70%; seroconversion>40%; and GMR>2.5). Two non-adjuvanted vaccine doses were required to meet the same licensure criteria. After first and second doses, percentage of subjects with HI titres ≥1:40 were between 97% and 100% in the adjuvanted vaccine groups compared with 68% and 91% in the non-adjuvanted group, respectively. Postvaccination seroconversion rates ranged from 91% to 98% in adjuvanted groups and were 68% (first dose) and 98% (second dose) in the non-adjuvanted group. HI titres ≥1:330 after primary doses were achieved in 69% to 90% in adjuvanted groups compared with 41% in the non-adjuvanted group. Long-term antibody persistence after priming and a robust antibody response to booster immunization were observed in all vaccination groups. All A/H1N1 vaccine formulations were generally well tolerated. No vaccine-related serious adverse events occurred, and no subjects were withdrawn from the study due to an adverse event. ConclusionsAn MF59-adjuvanted influenza vaccine containing 3.75μg of A/H1N1 antigen was well tolerated and sufficiently immunogenic to meet all the European licensure criteria after a single dose in healthy children 3–17 years old.

The safety of seasonal influenza vaccines in Australian children in 2013.

To examine influenza vaccine safety in Australian children aged under 10 years in 2013. Active prospective surveillance study conducted with parents or carers of children who received influenza vaccine in outpatient clinics at six tertiary paediatric hospitals or from selected primary health care providers between 18 March and 19 July 2013. Parental-reported frequency of systemic reactions (fever, headache, nausea, abdominal symptoms, convulsions, rash, rigors and fatigue), injection site reactions (erythema, swelling and/or pain at the injection site), use of antipyretics or analgesics, and medical attendance or advice within 72 hours after vaccination. Of 981 children enrolled in the surveillance, 893 children aged 6 months to <10 years were eligible for inclusion. These children received 1052 influenza vaccine doses. Fever was reported in 5.5% (95% CI, 4.1%-7.3%) and 6.5% (95% CI, 3.5%-10.9%) of children after Doses 1 and 2, respectively. One febrile convulsion occurred in a child with a known seizure disorder. Injection site reactions occurred in 21.2% (95% CI, 18.5%-24.1%) and 6.0% (95% CI, 3.1%-10.2%) after Doses 1 and 2, respectively; most were mild. Very few parents sought medical follow-up for their child's reaction: 22 (2.6%; 95% CI, 1.6%-3.9%) after Dose 1, and 11 (5.5%; 95% CI, 2.8%-9.6%) after Dose 2. These results are consistent with clinical trials and other observational studies of influenza vaccines currently registered for use in young children in Australia and can reassure parents and health care providers that influenza vaccination is safe and well tolerated.