Autoantibodies with a high prevalence in pneumococcal meningitis included anti-IFN-γ (66 of 623 [11%] vs. 3 of 264 [1%], p < 0.001), anti-IFN-λ3 (41 of 623 [7%] vs. 3 of 264 [1%], p = 0.01), anti-IFN-ω (65 of 623 [11%] vs. 1 of 264 [0%], p < 0.001), anti-IL-1α (32 of 623 [5%] vs. 1 of 264 [0%], p = 0.002), anti-IL-6 (75 of 623 [12%] vs. 3 of 264 [1%], p < 0.001), anti-IL-17A (55 of 623 [9%] vs. 2 of 264 [1%], p < 0.001), and anti-IL-17F (64 of 623 [10%] vs. 1 of 264 [0%], p < 0.001). Here, IL17A is linked to pneumococcal meningitis.