CPT® Code 90694

Influenza virus vaccine, quadrivalent (aIIV4), inactivated, adjuvanted, preservative free, 0.5 mL dosage, for intramuscular use

The CPT® Code 90694 refers to the quadrivalent influenza virus vaccine, specifically the adjuvanted inactivated influenza vaccine (aIIV4). This vaccine is designed for intramuscular use and is preservative-free, with a dosage of 0.5 mL. The term "quadrivalent" indicates that this vaccine is formulated to protect against four different strains of the influenza virus, which includes two distinct strains of influenza type A and two strains of type B. The vaccine is produced using embryonated chicken eggs, where the influenza virus is cultivated, harvested, and subsequently inactivated through the use of formaldehyde. The aIIV4 vaccine is classified as a subunit vaccine, meaning it contains only the specific antigens that are most effective in eliciting an immune response. The process of creating a subunit vaccine involves the identification and isolation of these essential antigens, which can be achieved through laboratory cultivation of the virus and the application of chemical methods to separate the antigens, or through recombinant DNA technology. To enhance the immune response, an adjuvant is incorporated into the vaccine formulation. In this case, the adjuvant used is MF59, which is an oil-in-water emulsion. The presence of MF59 aids in increasing the uptake of the antigen and promotes better binding of antibodies to the influenza virus. Additionally, it facilitates the recruitment of macrophages and enhances the migration of immune cells to lymph nodes, thereby improving the overall immune response. Research indicates that this adjuvanted vaccine may offer superior protection for children aged 6 to 23 months compared to non-adjuvanted vaccines. It is important to note that this code specifically pertains to the supply of the vaccine itself, while the administration of the vaccine via intramuscular injection is reported separately.