Pediatrics

Abstract

BACKGROUNDFew observational studies have evaluated the relative effectiveness of live attenuated (LAIV) and inactivated (IIV) influenza vaccines against medically attended laboratory-confirmed influenza.METHODSWe analyzed US Influenza Vaccine Effectiveness Network data from participants aged 2 to 17 years during 4 seasons (2010\u20132011 through 2013\u20132014) to compare relative effectiveness of LAIV and IIV against influenza-associated illness. Vaccine receipt was confirmed via provider/electronic medical records or immunization registry. We calculated the ratio (odds) of influenza-positive to influenza-negative participants among those age-appropriately vaccinated with either LAIV or IIV for the corresponding season. We examined relative effectiveness of LAIV and IIV by using adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression.RESULTSOf 6819 participants aged 2 to 17 years, 2703 were age-appropriately vaccinated with LAIV (n = 637) or IIV (n = 2066). Odds of influenza were similar for LAIV and IIV recipients during 3 seasons (2010\u20132011 through 2012\u20132013). In 2013\u20132014, odds of influenza were significantly higher among LAIV recipients compared with IIV recipients 2 to 8 years old (OR 5.36; 95% CI, 2.37 to 12.13). Participants vaccinated with LAIV or IIV had similar odds of illness associated with influenza A/H3N2 or B. LAIV recipients had greater odds of illness due to influenza A/H1N1pdm09 in 2 seasons: 2010 to 2011 (OR 5.53; 95% CI, 1.35 to 22.76) and 2013\u20132014 (OR 2.65; 95% CI, 1.34 to 5.27).CONCLUSIONSWe observed lower effectiveness of LAIV compared with IIV against influenza A/H1N1pdm09 but not A(H3N2) or B among children and adolescents, suggesting poor performance related to the LAIV A/H1N1pdm09 viral construct.20162017-02-01T00:00:00ZUL1 RR024153/RR/NCRR NIH HHS/United StatesUL1 TR000005/TR/NCATS NIH HHS/United StatesU01IP000467/IP/NCIRD CDC HHS/United StatesU01 IP000466/IP/NCIRD CDC HHS/United StatesU01 IP000473/IP/NCIRD CDC HHS/United StatesU01 IP000172/IP/NCIRD CDC HHS/United StatesU01 IP000471/IP/NCIRD CDC HHS/United StatesU01 IP000170/IP/NCIRD CDC HHS/United StatesUL1TR000005/TR/NCATS NIH HHS/United StatesU01 IP000183/IP/NCIRD CDC HHS/United StatesCC999999/Intramural CDC HHS/United StatesU01 IP000184/IP/NCIRD CDC HHS/United StatesU01IP000474/IP/NCIRD CDC HHS/United States26738884PMC4732363797