How does the inflammatory response help the body fight infections?

Hint: Inflammatory response is a type of response which is activated at the release of histamine, prostaglandins by the cells. These chemicals lead to swelling in the tissue and also attract WBCs which cause phagocytosis and pus formation.

Complete answer:
At the time of viral infection innate immunity is activated and cytokines are produced. There is a rapid increase in the number of cytokines at the infection site and inflammation is observed. Cytokines attract WBCs which eliminate the injurious agent or microorganism and the damaged tissue is also removed followed by the process of healing.
Cytokine namely Tumor necrosis factor-alpha (TNF-alpha) is the earliest cytokine which is produced by monocytes and macrophages. Inflammatory response is shown in response to TNF –alpha. Main indications of inflammation are pain, swelling, redness etc. There is an increase in the flow of blood because the capillaries are constricted. Permeability of capillaries is also increased which aids in entry and exit of fluids to the surrounding tissue. Erythema and increase in temperature of the tissue are also observed. Also a large number of phagocytes such as neutrophils cluster at the site of infection in case of inflammation.

Note:
Inflammatory response acts as a defence mechanism at the time of injury or infection. Inflammation for a few days is known as acute inflammation and for a longer time is called chronic inflammation. Four main signs of inflammation are redness, heat, swelling and pain. After acute inflammation, the damaged cells which have the power of regeneration proliferate and heal. Suppuration or pus formation is also observed.