TLR7 and influenza: Next, we evaluated the efficacy of the SE(Trojan-TLR7/8a) adjuvant against influenza through intramuscular immunization in combination with sM2HA2, a promising antigen that targets a broad range of influenza subtypes and is composed of influenza matrix protein 2 (sM2) and the stalk domain of hemagglutinin protein (HA2) [30].