Positive Health Online

Abstract

PODER and COLLEAGUES,  (1)Tartu University Clinics Foundation, Raja 31, Tartu, Estonia. Electronic address: airi@std.ee. (2)Pediatric Department, Faculty Hospital, Trenčín University AD, Trenčín, Slovakia. (3)GlaxoSmithKline Vaccines, King of Prussia, PA, USA conducted a randomized vaccination study in children to assess whether the study vaccines elicited satisfactory hemagglutination inhibition (HI) responses.

Background

Vaccination is an effective strategy to prevent influenza. This observer-blind, randomized study in children 10-17 years of age assessed whether the hemagglutination inhibition (HI) antibody responses elicited by H1N1/2009 vaccines adjuvanted with AS03 (an adjuvant system containing α-tocopherol and squalene in an oil-in-water emulsion) or without adjuvant, met the European regulatory immunogenicity criteria at Days 21 and 182.

Methodology

Three hundred and ten healthy children were randomized (3:3:3:5) to receive one dose of 3.75 μg hemagglutinin (HA) AS03A-adjuvanted vaccine, one or two doses of 1.9 μg HA AS03B-adjuvanted vaccine, or one dose of 15 μg HA pandemic vaccine. All children received a booster dose of the allocated vaccine at Day 182. Serum samples were tested for HI antibody response at Days 21, 42, 182 and 189.

Results

All vaccination regimens elicited HI antibody responses that met the European regulatory criteria at Days 21 and 42. HI antibody responses fulfilling European regulatory criteria were still observed six months after the first vaccine dose in all study vaccines groups. Two doses of 1.9 μg HA AS03B-adjuvanted vaccine elicited the strongest HI antibody response throughout the study. The non-adjuvanted 15 μg HA vaccine elicited a lower HI antibody response than the AS03-adjuvanted vaccines. At Day 189, the European regulatory criteria were met for all vaccines with baseline HI antibody titers as reference. An anamnestic response for all vaccines was suggested at Day 189, based on the rapid increase in HI antibody geometric mean titers (1.5-2.5-fold increase). Injection site reactogenicity was higher following the AS03-adjuvanted vaccines compared with the non-adjuvanted vaccine. No safety concerns were identified for any study vaccine.

Conclusion

All study vaccines elicited HI antibody responses that persisted at purported protective levels through six months after vaccination and fulfilled the European regulatory criteria.

References

Poder A(1), Simurka P(2), Li P(3), Roy-Ghanta S(3), Vaughn D(3). An observer-blind, randomized, multi-center trial assessing long-term safety and  immunogenicity of AS03-adjuvanted or unadjuvanted H1N1/2009 influenza vaccines in children 10-17 years of age.   Vaccine. 32(9):1121-9. Feb 19 2014. doi: 10.1016/j.vaccine.2013.11.031. Epub Nov 16 2013.