On the photonic side, a sharp peak centered at ω c = 1185cm -1 emerges when the first photonic excited state |v cav 1 ⟩ is included. This suggests that the rate modification inside the cavity is associated with the absorption or emission of one cavity photon. On the molecular side, a small peak in the rate profile is observed with N mol v = 3. Intriguingly, different from the reaction outside the cavity, the reaction rate for N mol v = 3 is larger than that for N mol v = 2 over the entire ω c range. This indicates that the presence of the cavity mode itself, even in the off-resonant condition, can alter the interference pattern between Path 1 and 2 shown in Fig. . The peak becomes significantly stronger and sharper with the inclusion of the vibrational state |v mol 3 ⟩ (N mol v = 4). Convergence is achieved when N mol v > 6. This clearly indicates that the vibrationally excited tunneling is involved in cavity-induced rate enhancement.