Vaccine efficacy consistent in subgroups according to age, sex, race, and previous influenza vaccination
WEDNESDAY, Oct. 27, 2021 (HealthDay News) — A cell culture-derived quadrivalent inactivated influenza vaccine (IIV4c) is efficacious against influenza among healthy children and adolescents, according to a study published online Oct. 14 in the New England Journal of Medicine.
Terence Nolan, Ph.D., from the University of Melbourne in Australia, and colleagues examined the efficacy of IIV4c using a Madin-Darby canine kidney cell line in children and adolescents aged 2 years to younger than 18 years. Participants from eight countries were enrolled in a randomized clinical trial comparing IIV4c to a noninfluenza vaccine (meningococcal ACWY) during three influenza seasons (2017 to 2019).
The researchers found that 7.8 percent of 2,257 participants in the IIV4c group and 16.2 percent of the 2,252 participants in the comparator group had laboratory-confirmed influenza; the efficacy of IIV4c was 54.6 percent. Efficacy was 80.7, 42.1, and 47.6 percent against influenza A/H1N1, influenza A/H3N2, and influenza B, respectively. In subgroups according to age, sex, race, and previous influenza vaccination, IIV4c showed consistent vaccine efficacy. The IIV4c and comparator groups had similar incidences of adverse events.
“We found that IIV4c provided protection against laboratory-confirmed influenza in healthy children and adolescents across three seasons, regardless of previous influenza vaccination,” the authors write. “Influenza vaccine manufacturing platforms that do not rely on eggs offer certain advantages, including avoidance of egg-adaptive hemagglutinin mutations and a shorter response time when a new influenza virus emerges.”
All study authors disclosed financial ties to Seqirus, which funded the study. Two authors also disclosed ties to other pharmaceutical companies.
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