Woolf T Walker,
Philip de Whalley, Nick Andrews,
Clarissa Oeser,
Michelle Casey,
Louise Michaelis,
Katja Hoschler,
Caroline Harrill,
Phoebe Moulsdale,
Ben Thompson, [......],
Tessa M John,
Ifeanyichukwu Okike,
Shamez Ladhani,
Richard Tomlinson,
Paul T Heath,
Elizabeth Miller,
Saul N Faust,
Matthew D Snape,
Adam Finn,
Andrew J Pollard
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ABSTRACT: We investigated antibody persistence in children 1 year after 2 doses of either an AS03(B)-adjuvanted split-virion or nonadjuvanted whole-virion monovalent pandemic influenza vaccine and assessed the immunogenicity and reactogenicity of a subsequent dose of trivalent influenza vaccine (TIV).
Children previously immunized at age 6 months to 12 years in the original study were invited to participate. After a blood sample was obtained to assess persistence of antibody against swine influenza A/H1N1(2009) pandemic influenza, children received 1 dose of 2010/2011 TIV, reactogenicity data were collected for 7 days, and another blood sample was obtained 21 days after vaccination.
Of 323 children recruited, 302 received TIV. Antibody persistence (defined as microneutralization [MN] titer ≥1:40) 1 year after initial vaccination was significantly higher in the AS03(B)-adjuvanted compared with the whole-virion vaccine group, 100% (95% confidence interval [CI], 94.1%-100%) vs 32.4% (95% CI, 21.5%-44.8%) in children immunized <3 years old and 96.9% (95% CI, 91.3%-99.4%) vs 65.9% (95% CI, 55.3%-75.5%) in those 3-12 years old at immunization, respectively (P < .001 for both groups). All children receiving TIV had post-vaccination MN titers ≥1:40. Although TIV was well tolerated in all groups, reactogenicity in children <5 years old was slightly greater in those who originally received AS03(B)-adjuvanted vaccine.
This study provides serological evidence that 2 doses of AS03(B)-adjuvanted pandemic influenza vaccine may be sufficient to maintain protection across 2 influenza seasons. Administration of TIV to children who previously received 2 doses of either pandemic influenza vaccine is safe and is immunogenic for the H1N1 strain.
Clinical Infectious Diseases 03/2012; 54(5):661-9. · 9.15 Impact Factor
