From the current study, it was concluded that sensitizing Wistar rats with P. equorum crude antigen extract led to inflammatory immune responses via increasing total leukocyte count on day 14 post-infection compared to other days of investigation and stimulating the production of antibodies, IgE and IgG, Th1- related cytokine (IFN-γ), and Th2 cytokines (IL-5, and IL-13), and innate immune responses (IL-33) particularly at days 7 and 14 post-injection. The gene discussed is IL33; the disease is infection.