title: Evaluation of anthrax vaccine safety in 18 to 20 year olds: A first step towards age de-escalation studies in adolescents.
abstract: OBJECTIVE
  Anthrax vaccine adsorbed (AVA, BioThrax(®)) is recommended for post-exposure prophylaxis administration for the US population in response to large-scale Bacillus anthracis spore exposure. However, no information exists on AVA use in children and ethical barriers exist to performing pre-event pediatric AVA studies. A Presidential Ethics Commission proposed a potential pathway for such studies utilizing an age de-escalation process comparing safety and immunogenicity data from 18 to 20 year-olds to older adults and if acceptable proceeding to evaluations in younger adolescents. We conducted exploratory summary re-analyses of existing databases from 18 to 20 year-olds (n=74) compared to adults aged 21 to 29 years (n=243) who participated in four previous US government funded AVA studies.
  
  
  METHODS
  Data extracted from studies included elicited local injection-site and systemic adverse events (AEs) following AVA doses given subcutaneously at 0, 2, and 4 weeks. Additionally, proportions of subjects with ≥4-fold antibody rises from baseline to post-second and post-third AVA doses (seroresponse) were obtained.
  
  
  RESULTS
  Rates of any elicited local AEs were not significantly different between younger and older age groups for local events (79.2% vs. 83.8%, P=0.120) or systemic events (45.4% vs. 50.5%, P=0.188). Robust and similar proportions of seroresponses to vaccination were observed in both age groups.
  
  
  CONCLUSIONS
  AVA was safe and immunogenic in 18 to 20 year-olds compared to 21 to 29 year-olds. These results provide initial information to anthrax and pediatric specialists if AVA studies in adolescents are required.
authors: Tunnell Contracting, Serving the Mission of: Health and Human Services (HHS)/Assistant Secretary for Preparedness and Response(ASPR)/Biomedical Advanced Research and Development Authority(BARDA), Thomas P. O'Neill Federal Building (FOB8), 200 C Street, SW, Washington, DC 20024. Electronic address: james.king@hhs.gov.
authors: James C
authors: JC
authors: King
authors: Health and Human Services (HHS)/Assistant Secretary for Preparedness and Response(ASPR)/Biomedical Advanced Research and Development Authority(BARDA), United States.
authors: Yonghong
authors: Y
authors: Gao
authors: MPIR Laboratory, MVPD/DBD/NCIRD, Centers for Disease Control & Prevention, MS-D01, Bldg. 23, Room 8-161, 1600 Clifton Road, Atlanta, GA 30333, United States.
authors: Conrad P
authors: CP
authors: Quinn
authors: Tunnell Contracting, Serving the Mission of: Health and Human Services (HHS)/Assistant Secretary for Preparedness and Response(ASPR)/Biomedical Advanced Research and Development Authority(BARDA), Thomas P. O'Neill Federal Building (FOB8), 200 C Street, SW, Washington, DC 20024.
authors: Thomas M
authors: TM
authors: Dreier
authors: GAP Solutions Inc. Supporting the Mission of Health and Human Services (HHS)/Assistant Secretary for Preparedness and Response(ASPR)/Biomedical Advanced Research and Development Authority(BARDA), United States.
authors: Cabrini
authors: C
authors: Vianney
authors: Health and Human Services (HHS)/Assistant Secretary for Preparedness and Response(ASPR)/Biomedical Advanced Research and Development Authority(BARDA), United States.
authors: Eric M
authors: EM
authors: Espeland
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000881:Anthrax / Q000517:prevention & control*; D022122:Anthrax Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology; D000907:Antibodies, Bacterial / Q000097:blood; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D022122:Anthrax Vaccines; D000907:Antibodies, Bacterial
keywords: Anthrax vaccine; Children; Pediatric medical countermeasure research; Presidential Ethics Committee