Abstract Title:

Shedding of Ann Arbor strain live attenuated influenza vaccine virus in children 6-59 months of age.

Abstract Source:

Vaccine. 2011 Apr 20. Epub 2011 Apr 20. PMID: 21513761

Abstract Author(s):

Raburn M Mallory, Tingting Yi, Christopher S Ambrose

Article Affiliation:

MedImmune, LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.

Abstract:

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.

Study Type : Human Study

Print Options


Key Research Topics

Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get Nature's Evidence-Based Pharmacy

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Download Now

500+ pages of Natural Medicine Alternatives and Information.

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2020 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.