mRNA-1083.3

mRNA-1083.3 is a second-generation combination vaccine candidate developed by Moderna for the prevention of both COVID-19 and influenza virus infections in adults[1][5][8]. It combines two messenger RNA (mRNA) components: - mRNA-1283, which encodes the receptor binding domain (RBD) and N-terminal domain (NTD) of the SARS-CoV-2 spike protein, - and mRNA-1010, which encodes hemagglutinin glycoproteins from influenza A/H1N1, A/H3N2, B/Yamagata, and B/Victoria strains[5][8]. The vaccine is administered intramuscularly as a sterile liquid injection[5]. Its mechanism of action is immunostimulation—delivering synthetic mRNAs that instruct host cells to produce viral antigens from both SARS-CoV‑2 and influenza viruses to elicit protective immune responses[1][8]. Phase 3 clinical data show that a single dose produces non-inferior or superior immune responses compared to licensed standalone vaccines for both flu (Fluzone High-Dose/Fluarix) and COVID‑19 (Spikevax), with an acceptable safety profile; common side effects include injection site pain, fatigue, myalgia, and headache[6][7][8].

Brand names

mCOMBRIAX

Other names

COVID+Flu vaccine - Moderna Therapeutics