Efficacy of Adjuvanted vs Conventional Quadrivalent Flu Vaccine Compared

MF59 adjuvanted, quadrivalent influenza vaccine (aQIV) was found to be more efficacious in preventing influenza than a non-adjuvanted conventional influenza vaccine in children aged 6 through 23 months.

Findings from a head-to-head study showed that MF59 adjuvanted, quadrivalent influenza vaccine (aQIV) provided greater efficacy vs a non-adjuvanted conventional influenza vaccine in pediatric patients aged 6–23 months. The study has been published in The Lancet Respiratory Medicine.

MF59 is a proprietary adjuvant that consists of an oil-in-water squalene-based emulsion. Study authors aimed to evaluate the relative efficacy, immunogenicity, and safety of MF59 aQIV vs a standard non-adjuvanted trivalent or quadrivalent inactivated influenza vaccine in children aged 6 months through 5 years by conducting a Phase 3 multicenter, randomized-controlled, observer-blinded trial (N=10,644). Vaccine-naive patients were given 2 doses of the study vaccine whereas non-naive patients received only one dose. 

The primary outcome was relative vaccine efficacy as assessed by RT-PCR-confirmed influenza due to any influenza strain. Other outcomes measured included immunogenicity against homologous and heterologous strains of influenza, as well as safety. 

Among patients aged 6 to 23 months, significant relative vaccine efficacy was observed with the aQIV vaccine vs the comparator vaccine (relative efficacy 31.37, 95% CI: 3.14-51.38). However, this difference was not seen in the overall study population (relative efficacy -0.67, 95% CI: -19.81 to 15.41). The data also showed that MF59 aQIV induced a superior immunogenic response in children aged 6 months to 5 years against both homologous and heterologous strains. The highest geometric mean titer ratios, however, were seen in patients aged 6 to 23 months. 

The safety profiles were similar for both vaccine arms but adverse events were reported more frequently with the aQIV vs comparator vaccine. 

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The authors concluded, “Although there was no additional benefit of [aQIV] compared with the US-licensed non-adjuvanted influenza vaccines in the overall study population, in the youngest and most vulnerable population of children in this trial, [aQIV] provided greater protection against influenza than a non-adjuvanted vaccine when assessed in this prespecified age group of 6 through 23 months.”

For more information visit sciencedirect.com.