Our objective was to evaluate the efficacy of influenza and meningococcal vaccinations in healthy subjects exposed to the anti-interleukin-17A (IL-17A) monoclonal antibody (MAb) secukinumab. We used an open-label, parallel-group, randomized single-center study of 50 healthy subjects. Subjects received a single 150-mg dose of secukinumab or no treatment, followed by vaccination with inactivated trivalent subunit influenza virus and conjugate group C meningococcal vaccine (Agrippal and Menjugate, respectively) 2 weeks later. Primary efficacy variables were responses of ≥4-fold increases in antibody titer (hemagglutination inhibition [HI; for influenza virus] and serum bactericidal assay [SBA; for Neisseria meningitides]) for meningococcus and influenza (at least two out of three serotypes), both at 4 weeks postvaccination. All subjects randomized to secukinumab (n = 25) or the control (n = 25) completed the study. Antibody responses to vaccinations measured at 4 weeks were comparable in both groups, with ≥4-fold increased responses following influenza virus vaccination of 20/25 (80%) for both groups and following meningococcal vaccination of 19/25 (76%) for the secukinumab group and 18/25 (72%) for the control group. Differences between groups were 0% (90% confidence intervals [CI], 19 and 19%) and 4% (90% CI, 16 and 24%) for influenza virus and meningococcal vaccines, respectively. Antibody responses were comparable between the 2 groups at different time points. Headache was the most frequently reported adverse effect. No deaths or serious adverse events were reported. Blockade of IL-17A by secukinumab does not appear to interfere with efficacy of influenza and meningococcal vaccinations, as assessed by the achievement of protective antibody levels. A protective (≥4-fold) immune response to both vaccinations at 4 weeks was achieved in 80 and 76% of subjects exposed to secukinumab and the control, respectively.