Harrington, W. N., Kackos, C. M. & Webby, R. J. The evolution and future of influenza pandemic preparedness. Exp. Mol. Med. 53, 737–749 (2021).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Javanian, M. et al. A brief review of influenza virus infection. J. Med. Virol. 93, 4638–4646 (2021).

Article  CAS  PubMed  Google Scholar 

Krammer, F. et al. Influenza. Nat. Rev. Dis. Prim. 4, 3 (2018).

Article  PubMed  Google Scholar 

Liang, Y. Pathogenicity and virulence of influenza. Virulence 14, 2223057 (2023).

Article  PubMed  PubMed Central  Google Scholar 

Charostad, J. et al. A comprehensive review of highly pathogenic avian influenza (HPAI) H5N1: an imminent threat at doorstep. Travel Med. Infect. Dis. 55, 102638 (2023).

Article  CAS  PubMed  Google Scholar 

Hui, D. S. & Zumla, A. Emerging respiratory tract viral infections. Curr. Opin. Pulm. Med. 21, 284–292 (2015).

Article  CAS  PubMed  Google Scholar 

Shi, J., Zeng, X., Cui, P., Yan, C. & Chen, H. Alarming situation of emerging H5 and H7 avian influenza and effective control strategies. Emerg. Microbes Infect. 12, 2155072 (2023).

Article  PubMed  Google Scholar 

Trombetta, C., Piccirella, S., Perini, D., Kistner, O. & Montomoli, E. Emerging influenza strains in the last two decades: a threat of a new pandemic? Vaccines 3, 172–185 (2015).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Graziosi, G., Lupini, C., Catelli, E. & Carnaccini, S. Highly pathogenic avian influenza (HPAI) H5 clade 2.3.4.4b virus infection in birds and mammals. Animals 14, https://doi.org/10.3390/ani14091372 (2024).

Henningson, J. N. et al. Comparative virulence of wild-type H1N1pdm09 influenza A isolates in swine. Vet. Microbiol. 176, 40–49 (2015).

Article  PubMed  Google Scholar 

Lewis, N. S. et al. Substitutions near the hemagglutinin receptor-binding site determine the antigenic evolution of influenza A H3N2 viruses in U.S. swine. J. Virol. 88, 4752–4763 (2014).

Article  PubMed  PubMed Central  Google Scholar 

Nfon, C. K. et al. Characterization of H1N1 swine influenza viruses circulating in Canadian pigs in 2009. J. Virol. 85, 8667–8679 (2011).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Rajao, D. S. et al. Novel reassortant human-like H3N2 and H3N1 influenza A viruses detected in pigs are virulent and antigenically distinct from endemic viruses. J. Virol. https://doi.org/10.1128/JVI.01675-15 (2015).

Kang, M. et al. Zoonotic infections by avian influenza virus: changing global epidemiology, investigation, and control. Lancet Infect. Dis. 24, e522–e531 (2024).

Article  PubMed  Google Scholar 

Soema, P. C., Kompier, R., Amorij, J. P. & Kersten, G. F. Current and next generation influenza vaccines: formulation and production strategies. Eur. J. Pharm. Biopharm. 94, 251–263 (2015).

Article  CAS  PubMed  Google Scholar 

McLean, H. Q. & Belongia, E. A. Influenza vaccine effectiveness: new insights and challenges. Cold Spring Harb. Perspect. Med. 11, https://doi.org/10.1101/cshperspect.a038315 (2021).

Ellebedy, A. H. et al. Induction of broadly cross-reactive antibody responses to the influenza HA stem region following H5N1 vaccination in humans. Proc. Natl. Acad. Sci. USA 111, 13133–13138 (2014).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Moser, C., Muller, M., Kaeser, M. D., Weydemann, U. & Amacker, M. Influenza virosomes as vaccine adjuvant and carrier system. Expert Rev. Vaccines 12, 779–791 (2013).

Article  CAS  PubMed  Google Scholar 

Wong, S. S. & Webby, R. J. Traditional and new influenza vaccines. Clin. Microbiol Rev. 26, 476–492 (2013).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Lee, I. T. et al. Safety and immunogenicity of a phase 1/2 randomized clinical trial of a quadrivalent, mRNA-based seasonal influenza vaccine (mRNA-1010) in healthy adults: interim analysis. Nat. Commun. 14, 3631 (2023).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Joshi, A. Y., Iyer, V. N., Hartz, M. F., Patel, A. M. & Li, J. T. Effectiveness of trivalent inactivated influenza vaccine in influenza-related hospitalization in children: a case-control study. Allergy Asthma Proc. 33, e23–e27 (2012).

Article  CAS  PubMed  Google Scholar 

Ng, S. et al. The effect of age and recent influenza vaccination history on the immunogenicity and efficacy of 2009-10 seasonal trivalent inactivated influenza vaccination in children. PLoS ONE 8, e59077 (2013).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Kissling, E. et al. Interim 2022/23 influenza vaccine effectiveness: six European studies, October 2022 to January 2023. Euro. Surveill. 28, https://doi.org/10.2807/1560-7917.ES.2023.28.21.2300116 (2023).

Dibben, O. et al. Defining the root cause of reduced H1N1 live attenuated influenza vaccine effectiveness: low viral fitness leads to inter-strain competition. NPJ Vaccines 6, 35 (2021).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Ilyushina, N. A. et al. Live attenuated and inactivated influenza vaccines in children. J. Infect. Dis. 211, 352–360 (2015).

Article  CAS  PubMed  Google Scholar 

Epperson, S. et al. Human infections with influenza A(H3N2) variant virus in the United States, 2011-2012. Clin. Infect. Dis. 57(Suppl 1), S4–S11 (2013).

Article  CAS  PubMed  Google Scholar 

Nachbagauer, R. & Palese, P. Is a universal influenza virus vaccine possible? Annu Rev. Med 71, 315–327 (2020).

Article  CAS  PubMed  Google Scholar 

Wang, W. C., Sayedahmed, E. E., Sambhara, S. & Mittal, S. K. Progress towards the development of a universal influenza vaccine. Viruses 14, https://doi.org/10.3390/v14081684 (2022).

Lim, C. M. L., Komarasamy, T. V., Adnan, N., Radhakrishnan, A. K. & Balasubramaniam, V. Recent advances, approaches and challenges in the development of universal influenza vaccines. Influenza Other Respir. Viruses 18, e13276 (2024).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Gomez Lorenzo, M. M. & Fenton, M. J. Immunobiology of influenza vaccines. Chest 143, 502–510 (2013).

Article  PubMed  PubMed Central  Google Scholar 

Cotter, C. R., Jin, H. & Chen, Z. A single amino acid in the stalk region of the H1N1pdm influenza virus HA protein affects viral fusion, stability and infectivity. PLoS Pathog. 10, e1003831 (2014).

Article  PubMed  PubMed Central  Google Scholar 

Krammer, F. & Palese, P. Influenza virus hemagglutinin stalk-based antibodies and vaccines. Curr. Opin. Virol. 3, 521–530 (2013).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Impagliazzo, A. et al. A stable trimeric influenza hemagglutinin stem as a broadly protective immunogen. Science 349, 1301–1306 (2015).

Article  CAS  PubMed  Google Scholar 

Yassine, H. M. et al. Hemagglutinin-stem nanoparticles generate heterosubtypic influenza protection. Nat. Med. 21, 1065–1070 (2015).

Article  CAS  PubMed  Google Scholar 

Bangaru, S. et al. A site of vulnerability on the influenza virus hemagglutinin head domain trimer interface. Cell 177, 1136–1152. e1118 (2019).

Article