TY - JOUR T1 - Shedding of Ann Arbor strain live attenuated influenza vaccine virus in children 6-59 months of age. AU - Mallory,Raburn M, AU - Yi,Tingting, AU - Ambrose,Christopher S, Y1 - 2011/04/20/ PY - 2010/12/17/received PY - 2011/04/04/revised PY - 2011/04/05/accepted PY - 2011/4/26/entrez PY - 2011/4/26/pubmed PY - 2011/10/1/medline SP - 4322 EP - 7 JF - Vaccine JO - Vaccine VL - 29 IS - 26 N2 - BACKGROUND: A trivalent, Ann Arbor strain, live attenuated influenza vaccine (LAIV) is approved for use in children 24 months of age and older in a number of countries. The incidence, duration, and other parameters of viral shedding after vaccination with LAIV have not been fully described in children ≤ 5 years of age. METHODS: An open-label, single-arm, multicenter, phase 2 study assessed viral shedding and safety in 200 children 6-59 months of age after a single, intranasal dose of LAIV in 2006. Participants were enrolled into 2 age groups: 6-23 months (n=100) and 24-59 months (n=100) of age. Viral shedding, reactogenicity, and adverse events were assessed for 28 days postvaccination. Serious adverse events and significant new medical conditions were monitored for 180 days postvaccination. RESULTS: Viral shedding was detected by culture in 79% (95% CI, 73-84) of vaccine recipients and occurred more frequently in children 6-23 months of age (89%) compared with children 24-59 months of age (69%). In total, 157 subjects shed vaccine, which was confirmed by RT-PCR as A/H1N1 for 128 subjects, A/H3N2 for 72 subjects, and B for 74 subjects. The incidence of shedding was highest on day 2 (59% in the 6-23 month age group; 41% in the 24-59 month age group) and most shedding occurred 1-11 days postvaccination; shedding after 11 days was infrequent and occurred almost exclusively in children 6-23 months of age. Mean titers of shed vaccine virus peaked on day 2 and were generally <10(3.0) median tissue culture infective dose/mL for both groups. Reactogenicity events peaked on day 2; runny/stuffy nose was reported most frequently (63% of all subjects). CONCLUSION: Most children 6-59 months of age vaccinated with Ann Arbor strain LAIV shed ≥ 1 vaccine virus within 11 days of vaccination. Shedding was less common in children 24-59 months of age, a population for whom LAIV is approved for use. Titers of shed vaccine were low, which may explain why secondary transmission of LAIV was observed very infrequently in a previous controlled study conducted with young children in a daycare setting. SN - 1873-2518 UR - https://www.unboundmedicine.com/medline/citation/21513761/Shedding_of_Ann_Arbor_strain_live_attenuated_influenza_vaccine_virus_in_children_6_59_months_of_age_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0264-410X(11)00534-2 DB - PRIME DP - Unbound Medicine ER -