CPT® Code 90655

A trivalent, split virus, preservative-free influenza vaccine (IIV3) is designed for intramuscular administration. This vaccine differs from immune globulins, which offer short-term, passive immunity, as it provides active, long-term immunity. The mechanism of action involves exposing the recipient's immune system to modified versions of specific influenza viruses, prompting the immune system to generate its own antibodies. This process enables the body to "remember" how to produce these antibodies upon subsequent exposure to the same antigens. The formulation is specifically preservative-free, meaning it does not contain the preservative thimerosal or contains only trace amounts, thus classified as either thimerosal-free or thimerosal-reduced. The U.S. Food and Drug Administration (FDA) recognizes both formulations as preservative-free. The vaccine is administered via intramuscular injection, which is a separate procedure that should be reported independently. The production of the influenza vaccine involves the use of embryonated chicken eggs, where the virus is harvested, inactivated with formaldehyde, concentrated, purified, and chemically disrupted to create a split virus. This trivalent vaccine is formulated to protect against three strains of influenza viruses, specifically two different strains of influenza type A and one strain of influenza type B. For billing purposes, the CPT® code 90655 is used to report the 0.25 mL dosage of the vaccine administered intramuscularly, while code 90656 is designated for the 0.5 mL dosage. It is important to note that these codes solely represent the vaccine product utilized, and the intramuscular injection must be reported separately.