Publications by authors named "Tanya Stoney"

9 Publications

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School-based HPV vaccination positively impacts parents' attitudes toward adolescent vaccination.

Vaccine 2021 Jul 12;39(30):4190-4198. Epub 2021 Jun 12.

Speciality of Child and Adolescent Health, Faculty of Medicine and Health, University of Sydney, NSW, Australia.

Introduction: This qualitative study aimed to explore parental attitudes, knowledge and decision-making about HPV vaccination for adolescents in the context of a gender-neutral school-based Australian National Immunisation Program (NIP).

Methods: Semi-structured interviews with parents of adolescents eligible for HPV vaccination were undertaken as part of an evaluation of a cluster-randomised controlled trial of a complex intervention in 40 schools (2013-2015). In this qualitative study, we purposively recruited a nested sample of parents from 11 schools across two Australian jurisdictions. Interviews explored parent knowledge and understanding of the HPV vaccine program; HPV vaccination decision-making; their adolescent's knowledge about HPV vaccination; and their adolescent's understanding about HPV vaccination, sexual awareness and behaviour. Transcripts were analysed using inductive and deductive thematic analysis.

Results: Parents' of 22 adolescents had positive attitudes towards the program; the school-based delivery platform was the key driver shaping acceptance of and decision-making about HPV vaccination. They had difficulty recalling, or did not read, HPV vaccination information sent home. Some adolescents were involved in discussions about vaccination, with parents' responsible for ultimate vaccine decision-making. All parents supported in-school education for adolescents about HPV and HPV vaccination. Parents' knowledge about HPV vaccination was limited to cervical cancer and was largely absent regarding vaccination in males.

Conclusions: Parents' positive attitudes towards the NIP and inclusion of the HPV vaccine is central to their vaccine decision-making and acceptance. More intensive communication strategies including school education opportunities are required to improve parents' knowledge of HPV-related disease and to promote vaccine decision-making with adolescents.
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July 2021

Respiratory Syncytial Virus Vaccination during Pregnancy and Effects in Infants.

N Engl J Med 2020 07;383(5):426-439

From the Medical Research Council, Respiratory and Meningeal Pathogens Research Unit, and the Department of Science and Technology-National Research Foundation, Vaccine Preventable Diseases, University of the Witwatersrand (S.A.M., C.L.C.), and Shandukani Research Centre, Wits Reproductive Health and HIV Institute (M.S.M.), Johannesburg, Setshaba Research Centre, Soshanguve (K.A., A.O.), and the Family Centre for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Tygerberg Hospital (M.F.C.), and the Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, South African Medical Research Council Unit on Child and Adolescent Health, University of Cape Town (H.J.Z.), Cape Town - all in South Africa; Fundación INFANT (F.P.P., R.L.), Hospital Militar Central Dr. Cosme Argerich (G.P.M.), and the National Scientific and Technical Research Council (R.L.), Buenos Aires, and the Department of Pediatric Pulmonology, Hospital del Niño Jesús, Tucumán (C.J.L.) - both in Argentina; the Departments of Pediatrics and Molecular Virology and Microbiology, Baylor College of Medicine, Houston (P.A.P., F.M.M.); the University of Auckland, Middlemore Hospital, Auckland, New Zealand (A.A.T.); the Department of Pediatrics, University of Colorado School of Medicine, and the Children's Hospital Colorado, Center for Global Health, Colorado School of Public Health, Aurora (E.A.F.S.); the Department of Obstetrics and Gynecology, Duke University, Durham, NC (G.K.S.); Novavax (S.A., A.A., J.C., I.C., A.F., J.S.P., V.S., D.N.T., J.W., G.M.G., L.F.F.), Gaithersburg, and the Department of International Health, International Center for Maternal and Newborn Health (A.H.B.), and the Center for American Indian Health, Department of International Health (L.H.), Johns Hopkins Bloomberg School of Public Health, Baltimore - all in Maryland; the Vaccine Institute (A.C., P.T.H.) and the Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute (A.K.), St. George's, University of London, London, Paediatric Infectious Diseases, Clinical and Experimental Sciences, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton (C.E.J.), and the Oxford Vaccine Group, Department of Paediatrics, University of Oxford and National Institute for Health Research Oxford Biomedical Research Centre (M.D.S.), and the Nuffield Department of Women's and Reproductive Health, University of Oxford (M.V.), Oxford - all in the United Kingdom; the Department of Pediatrics, Seattle Children's Hospital, University of Washington, Seattle (J.A.E.);the Department of Obstetrics and Gynecology, Wayne State University, Detroit (B.G.); the Research Institute for Tropical Medicine, Muntinlupa, Philippines (J.N.J., M.L.); the Department of Pediatrics (D.W.K.) and the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology and Center for Women's Reproductive Health (A.T.T.), University of Alabama, Birmingham; the Women's and Children's Hospital and Robinson Research Institute, University of Adelaide, Adelaide, SA (H.S.M.), the Melbourne School of Population and Global Health, University of Melbourne, and Murdoch Children's Research Institute, Parkville, VIC (T.M.N., K.P.P.), and Wesfarmers Center of Vaccines and Infectious Diseases, Telethon Kids Institute, Division of Paediatrics, School of Medicine, University of Western Australia, Perth Children's Hospital, Perth (P.C.R., T.S.) - all in Australia; Marshfield Clinic Research Institute, Marshfield, WI (J.K.M.); Pediatría Clínica, Infectología y Traslacional Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain (F.M.-T.); the Division of General Pediatrics, Department of Pediatrics, School of Medicine (J.H.S.), and the Department of Obstetrics and Gynecology (M.W.V.), University of Utah Health Sciences Center, Salt Lake City; Meridian Clinical Research, Norfolk, NE (K.V.); and the International Center for Diarrhoeal Disease Research Bangladesh, Dhaka (K.Z.).

Background: Respiratory syncytial virus (RSV) is the dominant cause of severe lower respiratory tract infection in infants, with the most severe cases concentrated among younger infants.

Methods: Healthy pregnant women, at 28 weeks 0 days through 36 weeks 0 days of gestation, with an expected delivery date near the start of the RSV season, were randomly assigned in an overall ratio of approximately 2:1 to receive a single intramuscular dose of RSV fusion (F) protein nanoparticle vaccine or placebo. Infants were followed for 180 days to assess outcomes related to lower respiratory tract infection and for 364 days to assess safety. The primary end point was RSV-associated, medically significant lower respiratory tract infection up to 90 days of life, and the primary analysis of vaccine efficacy against the primary end point was performed in the per-protocol population of infants (prespecified criterion for success, lower bound of the 97.52% confidence interval [CI] of ≥30%).

Results: A total of 4636 women underwent randomization, and there were 4579 live births. During the first 90 days of life, the percentage of infants with RSV-associated, medically significant lower respiratory tract infection was 1.5% in the vaccine group and 2.4% in the placebo group (vaccine efficacy, 39.4%; 97.52% CI, -1.0 to 63.7; 95% CI, 5.3 to 61.2). The corresponding percentages for RSV-associated lower respiratory tract infection with severe hypoxemia were 0.5% and 1.0% (vaccine efficacy, 48.3%; 95% CI, -8.2 to 75.3), and the percentages for hospitalization for RSV-associated lower respiratory tract infection were 2.1% and 3.7% (vaccine efficacy, 44.4%; 95% CI, 19.6 to 61.5). Local injection-site reactions among the women were more common with vaccine than with placebo (40.7% vs. 9.9%), but the percentages of participants who had other adverse events were similar in the two groups.

Conclusions: RSV F protein nanoparticle vaccination in pregnant women did not meet the prespecified success criterion for efficacy against RSV-associated, medically significant lower respiratory tract infection in infants up to 90 days of life. The suggestion of a possible benefit with respect to other end-point events involving RSV-associated respiratory disease in infants warrants further study. (Funded by Novavax and the Bill and Melinda Gates Foundation; NCT02624947.).
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July 2020

Risk of newly detected infections and cervical abnormalities in adult women seropositive or seronegative for naturally acquired HPV-16/18 antibodies.

Cancer Med 2019 08 5;8(10):4938-4953. Epub 2019 Jul 5.

Institut Català d'Oncologia (ICO), IDIBELL, CIBER-ESP, L'Hospitalet de Llobregat, Catalonia, Spain.

Background: Infections with human papillomavirus (HPV) types 16 and 18 account for ~70% of invasive cervical cancers but the degree of protection from naturally acquired anti-HPV antibodies is uncertain. We examined the risk of HPV infections as defined by HPV DNA detection and cervical abnormalities among women >25 years in the Human Papilloma VIrus Vaccine Immunogenicity ANd Efficacy trial's (VIVIANE, NCT00294047) control arm.

Methods: Serum anti-HPV-16/18 antibodies were determined at baseline and every 12 months in baseline DNA-negative women (N = 2687 for HPV-16 and 2705 for HPV-18) by enzyme-linked immunosorbent assay (ELISA) from blood samples. HPV infections were identified by polymerase chain reaction (PCR) every 6-months, and cervical abnormalities were confirmed by cytology every 12 months. Data were collected over a 7-year period. The association between the risk of type-specific infection and cervical abnormalities and serostatus was assessed using Cox proportional hazard models.

Results: Risk of newly detected HPV-16-associated 6-month persistent infections (PI) (hazard ratio [HR] = 0.56 [95%CI:0.32; 0.99]) and atypical squamous cells of undetermined significance (ASC-US+) (HR = 0.28 [0.12; 0.67]) were significantly lower in baseline seropositive vs baseline seronegative women. HPV-16-associated incident infections (HR = 0.81 [0.56; 1.16]) and 12-month PI (HR = 0.53 [0.24; 1.16]) showed the same trend. A similar trend of lower risk was observed in HPV-18-seropositive vs -seronegative women (HR = 0.95 [0.59; 1.51] for IIs, HR = 0.43 [0.16; 1.13] for 6-month PIs, HR = 0.31 [0.07; 1.36] for 12-month PIs, and HR = 0.61 [0.23; 1.61] for ASC-US+).

Conclusions: Naturally acquired anti-HPV-16 antibodies were associated with a decreased risk of subsequent infection and cervical abnormalities in women >25 years. This possible protection was lower than that previously reported in 15- to 25-year-old women.
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August 2019

The clinical, immunological and microbiological impact of the 10-valent pneumococcal-Protein D conjugate vaccine in children with recurrent protracted bacterial bronchitis, chronic suppurative lung disease and bronchiectasis: A multi-centre, double-blind, randomised controlled trial.

Hum Vaccin Immunother 2018 12;14(11):2768-2779. Epub 2018 Jul 12.

d School of Medicine and Menzies Health Institute Queensland, Griffith University , Southport , Queensland , Australia.

We aimed to determine the efficacy of the 10-valent pneumococcal- protein D conjugate vaccine (PHiD-CV) in children aged 18-months to <18-years with recurrent protracted bacterial bronchitis (rPBB), chronic suppurative lung disease (CSLD) or bronchiectasis. In a multi-centre, double-blind randomised controlled trial, children received two doses, 2-months apart of the 10vPHiD-CV or quadrivalent meningococcal-ACYW conjugate vaccine. Active surveillance for acute exacerbations, respiratory symptoms and antibiotic use was undertaken through to 12-months after the second vaccine dose (clinical cohort only). Serum, saliva and nasopharyngeal swabs were collected to measure immunological and microbiological effects (immunology cohort). Between December 2012 and August 2015, 62 children were enrolled onto the clinical protocol (1 excluded from clinical analyses due to unblinding), while 74 contributed to the immunology cohort (overall mean age = 6.8-years (standard deviation = 3.7), 42 (56.8%) male). The absolute risk difference comparing the 10vPHiD-CV group (n = 31 children) to the MenACYW group (n = 30 children) for acute exacerbations was -0.5 exacerbations/100-weeks at risk (95% confidence interval (CI) -2.0, 0.9). Compared to the MenACYW group, children who received the 10vPHiD-CV were less likely to have respiratory symptoms in each fortnight of surveillance (incidence density ratio (IDR) 0.82, 95%CI 0.61, 1.10) and required fewer short-course (<14-days duration) antibiotics (IDR 0.81, 95% CI 0.61, 1.09). The vaccine was immunogenic and no serious adverse events related to the vaccine were reported. In conclusion, 10vPHiD-CV might have a future role in managing children with rPBB, CSLD and bronchiectasis, but larger multicentre trials are needed to confirm or refute findings from this preliminary study.
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July 2018

Efficacy, safety, and immunogenicity of the human papillomavirus 16/18 AS04-adjuvanted vaccine in women older than 25 years: 7-year follow-up of the phase 3, double-blind, randomised controlled VIVIANE study.

Lancet Infect Dis 2016 Oct 28;16(10):1154-1168. Epub 2016 Jun 28.

GSK Vaccines, Wavre, Belgium.

Background: Although the risk of human papillomavirus (HPV) infection is greatest in young women, women older than 25 years remain at risk. We present data from the VIVIANE study of the HPV 16/18 AS04-adjuvanted vaccine in adult women after 7 years of follow-up.

Methods: In this phase 3, double-blind, randomised controlled trial, healthy women older than 25 years were enrolled (age stratified: 26-35 years, 36-45 years, and ≥46 years). Up to 15% in each age stratum had a history of HPV infection or disease. Women were randomly assigned (1:1) to receive HPV 16/18 vaccine or aluminium hydroxide control, with an internet-based system. The primary endpoint was vaccine efficacy against 6-month persistent infection or cervical intraepithelial neoplasia grade 1 or greater (CIN1+) associated with HPV 16/18. We did analyses in the according-to-protocol cohort for efficacy and total vaccinated cohort. Data for the combined primary endpoint in the according-to-protocol cohort for efficacy were considered significant when the lower limit of the 96·2% CI around the point estimate was greater than 30%. For all other endpoints and cohorts, data were considered significant when the lower limit of the 96·2% CI was greater than 0%. This study is registered with, number NCT00294047.

Findings: The first participant was enrolled on Feb 16, 2006, and the last study visit took place on Jan 29, 2014. 4407 women were in the according-to-protocol cohort for efficacy (n=2209 vaccine, n=2198 control) and 5747 women in the total vaccinated cohort (n=2877 vaccine, n=2870 control). At month 84, in women seronegative for the corresponding HPV type in the according-to-protocol cohort for efficacy, vaccine efficacy against 6-month persistent infection or CIN1+ associated with HPV 16/18 was significant in all age groups combined (90·5%, 96·2% CI 78·6-96·5). Vaccine efficacy against HPV 16/18-related cytological abnormalities (atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion) and CIN1+ was also significant. We also noted significant cross-protective efficacy against 6-month persistent infection with HPV 31 (65·8%, 96·2% CI 24·9-85·8) and HPV 45 (70·7%, 96·2% CI 34·2-88·4). In the total vaccinated cohort, vaccine efficacy against CIN1+ irrespective of HPV was significant (22·9%, 96·2% CI 4·8-37·7). Serious adverse events related to vaccination occurred in five (0·2%) of 2877 women in the vaccine group and eight (0·3%) of 2870 women in the control group.

Interpretation: In women older than 25 years, the HPV 16/18 vaccine continues to protect against infections, cytological abnormalities, and lesions associated with HPV 16/18 and CIN1+ irrespective of HPV type, and infection with non-vaccine types HPV 31 and HPV 45 over 7 years of follow-up.

Funding: GlaxoSmithKline Biologicals SA.
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October 2016 study protocol: a cluster randomised controlled evaluation of education, decisional support and logistical strategies in school-based human papillomavirus (HPV) vaccination of adolescents.

BMC Public Health 2015 Sep 15;15:896. Epub 2015 Sep 15.

School of Public Health, University of Sydney, Sydney, NSW, Australia.

Background: The National Human Papillomavirus (HPV) Vaccination Program in Australia commenced in 2007 for females and in 2013 for males, using the quadrivalent HPV vaccine (HPV 6,11,16,18). Thus far, we have demonstrated very substantial reductions in genital warts and in the prevalence of HPV among young Australian women, providing early evidence for the success of this public health initiative. Australia has a long history of school-based vaccination programs for adolescents, with comparatively high coverage. However, it is not clear what factors promote success in a school vaccination program. The study aims to examine: 1) student knowledge about HPV vaccination; 2) psycho-social outcomes and 3) vaccination uptake.

Methods/design: is a cluster randomised trial of a complex intervention in schools aiming to recruit 40 schools with year-8 enrolments above 100 students (approximately 4400 students). The schools will be stratified by Government, Catholic, and Independent sectors and geographical location, with up to 20 schools recruited in each of two states, Western Australia (WA) and South Australia (SA), and randomly allocated to intervention or control (usual practice). Intervention schools will receive the complex intervention which includes an adolescent intervention (education and distraction); a decisional support tool for parents and adolescents and logistical strategies (consent form returns strategies, in-school mop-up vaccination and vaccination-day guidelines). Careful process evaluation including an embedded qualitative evaluation will be undertaken to explore in depth possible mechanisms for any observed effect of the intervention on primary and secondary outcomes.

Discussion: This study is the first to evaluate the relative effectiveness of various strategies to promote best practice in school-based vaccination against HPV. The study aims to improve vaccination-related psychosocial outcomes, including adolescent knowledge and attitudes, decision-making involvement, self-efficacy, and to reduce fear and anxiety. The study also aims to improve school vaccination program logistics including reduction in time spent vaccinating adolescents and increased number of consent forms returned (regardless of decision). Less anxiety in adolescents will likely promote more efficient vaccination, which will be more acceptable to teachers, nurses and parents. Through these interventions, it is hoped that vaccination uptake will be increased.

Trial Registration: Australian and New Zealand Clinical Trials Registry, ACTRN12614000404628 , 14.04.2014.
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September 2015

Five-year Antibody Persistence and Safety After a Single Dose of Combined Haemophilus influenzae Type B Neisseria meningitidis Serogroup C-Tetanus Toxoid Conjugate Vaccine in Haemophilus influenzae Type B-primed Toddlers.

Pediatr Infect Dis J 2015 Dec;34(12):1379-84

From the *National Centre for Immunisation Research and Surveillance (NCIRS), The Children's Hospital at Westmead, University of Sydney, Sydney, New South Wales, Australia; †Vaccine and Immunisation Research Group, Murdoch Children's Research Institute, University of Melbourne, Carlton, Australia; ‡School of Population and Global Health, University of Melbourne, Carlton, Australia; §Canberra Hospital, Woden, Canberra, Australia; ¶School of Paediatrics and Child Health, University of Western Australia, Perth, Australia; ‖Telethon Kids Institute, Perth, Australia; **Princess Margaret Hospital for Children, Perth, Australia; ††Vaccine Trials Group, University of Western Australia Centre for Child Health Research and Vaccine Trials Group, Telethon Kids Institute for Child Health Research, Perth, Australia; ‡‡Royal Children's Hospital, Brisbane, Queensland, Australia; §§School of Paediatrics and Reproductive Health, Robinson Research Institute, Women's and Children's Hospital, University of Adelaide, Adelaide, Australia; ¶¶GSK Vaccines, Wavre, Belgium; ‖‖GSK Pharmaceuticals Limited, Bangalore, Karnataka, India; and ***GSK Vaccines, King of Prussia, Philadelphia, Pennsylvania.

Background: Antibody persistence is evaluated in healthy Australian children 4 and 5 years postvaccination with a single dose of combined Haemophilus influenzae type b-Neisseria meningitidis serogroup C tetanus toxoid conjugate vaccine (Hib-MenC-TT) compared with separately administered Hib-TT and MenC-CRM197 vaccines (Hib + MCC).

Methods: This is another follow-up of a phase III, open, randomized, controlled study (NCT00326118), in which 433 Hib-primed but MenC naïve toddlers aged 12-18 months were randomized 3:1 to receive Hib-MenC-TT or Hib + MCC vaccines. Protection against (1) MenC was measured by serum bactericidal antibody assay using rabbit complement (rSBA) and (2) Hib was measured by enzyme-linked immunosorbent assay of antibodies to polyribosylribitol phosphate (anti-PRP). Study children were assessed for any potentially vaccine-related serious adverse events at each persistence study visit.

Results: The according-to-protocol cohorts for persistence at years 4 and 5 included 282 and 263 children, respectively. The percentages of children with rSBA-MenC titers ≥1:8 at years 4 and 5 were 12.5% and 19.0%, respectively, in the Hib-MenC group; and 12.3% and 25.0% in the Hib + MCC group. All children in each group had anti-PRP concentrations ≥0.15 μg/mL at year 5. Exploratory analyses suggested no potential differences between groups in rSBA-MenC or anti-PRP antibody persistence. No vaccine-related serious adverse events were reported.

Conclusions: Antibody persistence was similar for years 4 and 5 after Hib-MenC-TT or Hib + MCC vaccination, with the majority of children retaining anti-PRP antibody concentrations ≥0.15 μg/mL at both timepoints. The percentage of children retaining rSBA-MenC titers ≥1:8 was low (≤25%), suggesting that a MenC booster dose may be warranted before adolescence.
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December 2015

Three-year antibody persistence and safety after a single dose of combined haemophilus influenzae type b (Hib)-Neisseria meningitidis serogroup C-tetanus toxoid conjugate vaccine in Hib-primed toddlers.

Pediatr Infect Dis J 2013 Feb;32(2):169-74

National Centre for Immunisation Research and Surveillance (NCIRS), The Children's Hospital at Westmead, Sydney, Australia.

Background: Persistence of seroprotective bactericidal antibody titers is important for long-term protection against meningococcal serogroup C disease in young children. Antibody persistence values were determined in children up to 3 years after vaccination with a single dose of the combined Haemophilus influenzae type b (Hib)-Neisseria meningitidis serogroup C (MenC)-tetanus toxoid (TT) conjugate vaccine (Hib-MenC-TT; NCT00326118).

Methods: The children had been randomized at ages 12-18 months to receive either 1 dose of Hib-MenC-TT (Hib-MenC group) or separately administered Hib-TT conjugate vaccine and MenC-CRM197 (MCC) vaccine (Hib plus MCC group). All children had been primed in infancy with a Hib vaccine. Antibodies against MenC were measured by a serum bactericidal assay using rabbit complement (rSBA-MenC) and antibodies against Hib polyribosylribitol phosphate were assessed by enzyme-linked immunosorbent assay.

Results: The rSBA-MenC titers ≥1:8 were demonstrated 3 years after vaccination in 64.2% and 53.2% of participants in the Hib-MenC group and in the Hib plus MCC group, respectively. Antipolyribosylribitol phosphate concentrations ≥0.15 µg/mL persisted in >98% of participants in both groups. The rSBA-MenC geometric mean titers and antipolyribosylribitol phosphate geometric mean concentrations remained higher 3 years after vaccination than before vaccination. No serious adverse events assessed by the investigator as being related to vaccination were reported.

Conclusion: In this antibody persistence study of Hib-primed but MenC-naïve toddlers who received a single dose of Hib-MenC-TT, protective antibody levels against Hib and MenC were maintained in the majority of children 3 years after vaccination.
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February 2013

Safety and immunogenicity of a prototype adjuvanted inactivated split-virus influenza A (H5N1) vaccine in infants and children.

Vaccine 2008 Nov 16;26(50):6383-91. Epub 2008 Sep 16.

Melbourne School of Population Health, The University of Melbourne, Victoria, Australia.

Objective: Highly pathogenic avian influenza A virus (H5N1) is a leading candidate for the next influenza pandemic, and infants and children may play an important role in transmission in a pandemic. Our objective was to evaluate the safety and immunogenicity of a prototype inactivated, aluminium adjuvanted, split-virus, clade 1 H5N1 vaccine (A/Vietnam/1194/2004/NIBRG-14) in infants and children aged > or =6 months to < 9 years.

Methods: Healthy infants and children (N=150) received two doses of 30 microg or 45 microg H5 HA with AlPO4 adjuvant 21 days apart. Serum samples were collected for virus microneutralisation (MN) and haemagglutination inhibition (HI) assays on Days 0, 21, and 42. Six-month antibody persistence following second vaccine dose was assessed by MN, and cross-reactive HI antibodies to a clade 2 variant strain (INDO5/RG2) were evaluated at Day 42.

Findings: Both formulations were well-tolerated. Two doses of 30 microg or 45 microg H5 HA formulations elicited strong immune responses by both MN (98-99% > or =1:20) and HI assays (95-100% > or =1:32), with 80-87% of children having MN antibody persistence (> or =1:20) up to 6 months post-vaccination. Additionally, robust cross-clade HI antibody responses were elicited following two doses.

Interpretation: Two doses of prototype 30 microg or 45 microg aluminium-adjuvanted, H5N1 vaccines were highly immunogenic and well-tolerated, with considerable antibody persistence 6 months after the primary vaccination course. Additional cross-clade HI antibody responses and an acceptable safety and tolerability profile support the use of the either candidate vaccine formulations in infants and children in the event of a pandemic.
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November 2008