 Influenza vaccines are crucial in preventing and reducing the consequences of the disease, particularly among high-risk groups. Although hemagglutination inhibition and single radial hemolysis are the only serological assays that can determine correlates of protection, cell-mediated immunity, CMI, plays an important role in host immune response against virus-related illness and establishing long-term immunological memory. While there are no current correlates of protection for CMI, it is advisable to investigate this kind of immunological response for the evaluation of next-generation vaccines. This article was authored by Egin Cechi, Atorelli, and E. Montomale.