(HealthDay News) – A candidate inactivated quadrivalent influenza vaccine (QIV) is efficacious for preventing influenza in young children, according to a study published online Dec. 11 in the New England Journal of Medicine.

Varsha K. Jain, MD, MPH, from GlaxoSmithKline Vaccines in King of Prussia, PA, and colleagues conducted a multinational phase 3 study involving 3- to 8-year-olds who were randomized to receive the QIV or hepatitis A vaccine (control). Real-time polymerase chain reaction (rt-PCR)-confirmed influenza A or B was the primary end point. The vaccine efficacy was analyzed in the total vaccinated cohort (2,584 children in each group) and in the per-protocol cohort (2,379 in the QIV and 2,398 in the control group).

The researchers found that 2.4% of children in the QIV group and 5.73% in the control group had rt-PCR-confirmed influenza, representing 59.3% QIV efficacy. The attack rate was 0.62% in the QIV group and 2.36% in the control group for moderate-to-severe rt-PCR-confirmed influenza, representing 74.2% QIV efficacy. In the per-protocol cohort, QIV efficacy was 55.4% and efficacy among children with moderate-to-severe influenza was 73.1%. Compared with the control vaccine, the QIV was associated with reduced risks of a body temperature above 39 degrees Celsius and lower respiratory tract illness, in the per-protocol cohort (relative risks, 0.29 and 0.2, respectively).

“These results highlight the potential clinical benefit of administering inactivated influenza vaccines in healthy children,” the authors write.

Several authors disclosed financial ties to pharmaceutical companies, including GlaxoSmithKline, which funded the study.

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