Influenza (Seasonal). https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal) (Accessed 17 Oct 2024).
Wiley, D. C., Wilson, I. A. & Skehel, J. J. Structural identification of the antibody-binding sites of hong kong influenza haemagglutinin and their involvement in antigenic variation. Nature 289, 373–378 (1981).
CDC. CDC Seasonal Flu Vaccine Effectiveness Studies. Flu Vaccines Work. https://www.cdc.gov/flu-vaccines-work/php/effectiveness-studies/index.html (Aaccessed 17 Oct 2024).
Davis, C. W. et al. Influenza vaccine–induced human bone marrow plasma cells decline within a year after vaccination. Science 370, 237–241 (2020).
Henry, C., Palm, A.-K. E., Krammer, F. & Wilson, P. C. From original antigenic sin to the universal influenza virus vaccine. Trends Immunol. 39, 70–79 (2018).
Settembre, E. C., Dormitzer, P. R. & Rappuoli, R. Bringing influenza vaccines into the 21st century. Hum. Vaccin. Immunother. 10, 600–604 (2014).
Li, Z., Zhao, Y., Li, Y. & Chen, X. Adjuvantation of influenza vaccines to induce cross-protective immunity. Vaccines (Basel) 9, 75 (2021).
Kim, J. H., Davis, W. G., Sambhara, S. & Jacob, J. Strategies to alleviate original antigenic sin responses to influenza viruses. Proc. Natl. Acad. Sci. 109, 13751–13756 (2012).
De Gregorio, E., Tritto, E. & Rappuoli, R. Alum adjuvanticity: unraveling a century old mystery. Eur. J. Immunol. 38, 2068–2071 (2008).
Ehrlich, H. J. et al. A clinical trial of a whole-virus H5N1 vaccine derived from cell culture. N. Engl. J. Med. 358, 2573–2584 (2008).
Zhu, F.-C. et al. A novel influenza A (H1N1) vaccine in various age groups. N. Engl. J. Med. 361, 2414–2423 (2009).
Young, B. E., Sadarangani, S. P. & Leo, Y. S. The Avian influenza vaccine Emerflu. Why did it fail? Expert Rev. Vaccines 14, 1125–1134 (2015).
Song, B. et al. Irreversible denaturation of proteins through aluminum-induced formation of backbone ring structures. Angew. Chem. Int. Ed. 53, 6358–6363 (2014).
O’Hagan, D. T., Ott, G. S., Nest, G. V., Rappuoli, R. & Giudice, G. D. The history of MF59(®) adjuvant: a phoenix that arose from the ashes. Expert Rev. Vaccines 12, 13–30 (2013).
Higgins, D. A., Carlson, J. R. & Van Nest, G. MF59 Adjuvant enhances the immunogenicity of influenza vaccine in both young and old mice. Vaccine 14, 478–484 (1996).
Cataldo, D. M. & Van Nest, G. The adjuvant MF59 increases the immunogenicity and protective efficacy of subunit influenza. Vaccin. Mice. Vaccin. 15, 1710–1715 (1997).
Ou, H. et al. Longevity of protective immune responses induced by a split influenza A (H7N9) vaccine mixed with MF59 adjuvant in BALB/c Mice. Oncotarget 8, 91828–91840 (2017).
Nakaya, H. I. et al. Systems biology of immunity to MF59-adjuvanted versus nonadjuvanted trivalent seasonal influenza vaccines in early childhood. Proc. Natl. Acad. Sci. 113, 1853–1858 (2016).
Palladino, G., Ferrari, A., Music, N., Settembre, E. C. & Wen, Y. Improved immunologic responses to heterologous influenza strains in children with low preexisting antibody response vaccinated with MF59-adjuvanted influenza. Vaccin. Vaccin. 39, 5351–5357 (2021).
Tsai, T. F. Fluad®-MF59®-adjuvanted influenza vaccine in older adults. Infect. Chemother. 45, 159–174 (2013).
O’Hagan, D. T., van der Most, R., Lodaya, R. N., Coccia, M. & Lofano, G. World in Motion”—emulsion adjuvants rising to meet the pandemic challenges. npj Vaccines 6, 1–15 (2021).
Rappuoli, R., Alter, G. & Pulendran, B. Transforming vaccinology. Cell 187, 5171–5194 (2024).
Querec, T. D. et al. Systems biology approach predicts immunogenicity of the yellow fever vaccine in humans. Nat. Immunol. 10, 116–125 (2009).
Gaucher, D. et al. Yellow fever vaccine induces integrated multilineage and polyfunctional immune responses. J. Exp. Med. 205, 3119–3131 (2008).
Wagoner, Z. W. et al. Systems immunology analysis of human immune organoids identifies host-specific correlates of protection to different influenza vaccines. Cell Stem Cell 32, 529–546.e6 (2025).
Krol, A. C., Abu-Shaar, M. & Brady, P. From the bench to the pharmacy: protecting innovation during vaccine development and commercialization. Methods Mol. Biol. 1404, 813–834 (2016).
Singleton, K. L., Joffe, A. & Leitner, W. W. Review: current trends, challenges, and success stories in adjuvant research. Front. Immunol. 14 (2023).
Adjuvant Comparison & Characterization (ACC) | NIAID: National Institute of Allergy and Infectious Diseases. https://www.niaid.nih.gov/research/adjuvant-comparison-characterization-acc (Accessed 22 Nov 2024).
Galeas-Pena, M. et al. A novel outer membrane vesicle adjuvant improves vaccine protection against bordetella pertussis. NPJ Vaccines 9, 190 (2024).
Prior, J. T. et al. Bacterial-derived outer membrane vesicles are potent adjuvants that drive humoral and cellular immune responses. Pharmaceutics 13, 131 (2021).
Harrell, J. E. et al. An outer membrane vesicle-adjuvanted oral vaccine protects against lethal, oral salmonella infection. Pathogens 10, 616 (2021).
Lathrop, S. K. et al. Vaccination with ancestral SARS-CoV-2 spike adjuvanted with TLR agonists provides cross-protection against XBB.1. npj Viruses 2, 28 (2024).
Hernandez-Davies, J. E. et al. Administration of multivalent influenza virus recombinant hemagglutinin vaccine in combination-adjuvant elicits broad reactivity beyond the vaccine components. Front. Immunol. 12, 692151 (2021).
Hernandez-Davies, J. E. et al. Magnitude and breadth of antibody cross-reactivity induced by recombinant influenza hemagglutinin trimer vaccine is enhanced by combination adjuvants. Sci. Rep. 12, 9198 (2022).
Felgner, J. et al. Broad antibody and T cell responses to Ebola, Sudan, and Bundibugyo Ebolaviruses using mono- and multi-valent adjuvanted glycoprotein vaccines. Antivir. Res 225, 105851 (2024).
Dollinger, E. et al. Combination adjuvant improves influenza virus immunity by downregulation of immune homeostasis genes in lymphocytes. Immunohorizons 9, vlae007 (2025).
Trombetta, C. M., Perini, D., Mather, S., Temperton, N. & Montomoli, E. Overview of serological techniques for influenza vaccine evaluation: past, present and future. Vaccines 2, 707 (2014).
Jeisy-Scott, V. et al. TLR7 Recognition is dispensable for influenza virus A infection but important for the induction of hemagglutinin-specific antibodies in response to the 2009 pandemic split vaccine in mice. J. Virol. 86, 10988–10998 (2012).
Shichinohe, S. & Watanabe, T. Advances in adjuvanted influenza vaccines. Vaccines (Basel) 11, 1391 (2023).
Athearn, K., Sample, C. J., Barefoot, B. E., Williams, K. L. & Ramsburg, E. A. Acute reactogenicity after intramuscular immunization with recombinant vesicular stomatitis virus is linked to production of IL-1β. PLOS ONE 7, e46516 (2012).
Rady, H. F., Dai, G., Huang, W., Shellito, J. E. & Ramsay, A. J. Flagellin encoded in gene-based vector vaccines is a route-dependent immune adjuvant. PLoS ONE 11, e0148701 (2016).
Atukorale, P. U. et al. Nanoparticle encapsulation of synergistic immune agonists enables systemic codelivery to tumor sites and ifnβ-driven antitumor immunity. Cancer Res. 79, 5394–5406 (2019).
Zhou, S. et al. The predominant Quillaja Saponaria fraction, QS-18, is safe and effective when formulated in a liposomal murine cancer peptide vaccine. J. Controlled Release 369, 687–695 (2024).
Tang, X. et al. Durable protective efficiency provide by mRNA vaccines require robust immune memory to antigens and weak immune memory to lipid nanoparticles. Mater. Today Bio 25, 100988 (2024).
Hervé, C., Laupèze, B., Del Giudice, G., Didierlaurent, A. M. & Tavares Da Silva, F. The how’s and what’s of vaccine reactogenicity. npj Vaccines 4, 39 (2019).
Nakayama, T. An inflammatory response is essential for the development of adaptive immunity-immunogenicity and immunotoxicity. Vaccine 34, 5815–5818 (2016).
Burny, W. et al. ECR-002 study group. different adjuvants induce common innate pathways that are associated with enhanced adaptive responses against a model antigen in humans. Front Immunol. 8, 943 (2017).
Andersen-Nissen, E. et al. Innate immune signatures to a partially-efficacious HIV vaccine predict correlates of HIV-1 infection risk. PLoS Pathog. 17, e1009363 (2021).
Sáez-Peñataro, J. et al. Association between reactogenicity and immunogenicity in a vaccinated cohort with two mRNA SARS-CoV-2 vaccines at a high-complexity reference hospital: a post hoc analysis on immunology aspects of a prospective cohort study. Vaccines (Basel) 12, 665 (2024).
Wolz, O.-O. et al. Innate responses to the former COVID-19 vaccine candidate CVnCoV and their relation to reactogenicity and adaptive immunogenicity. Vaccines (Basel) 12, 388 (2024).
Reinke, S., Thakur, A., Gartlan, C., Bezbradica, J. S. & Milicic, A. Inflammasome-mediated immunogenicity of clinical and experimental vaccine adjuvants. Vaccines (Basel) 8, 554 (2020).
Ella, R. et al. Safety and immunogenicity of an inactivated SARS-CoV-2 Vaccine, BBV152: a double-blind, randomised, phase 1 trial. Lancet Infect. Dis. 21, 637–646 (2021).
Ganneru, B. et al. Th1 skewed immune response of whole virion inactivated SARS CoV 2 vaccine and its safety evaluation. iScience 24, 102298 (2021).
Counoupas, C. et al. High-titer neutralizing antibodies against the SARS-CoV-2 delta variant induced by alhydroxyquim-II-adjuvanted trimeric spike antigens. Microbiol Spectr. 10, e0169521 (2022).
Beesu, M. et al. Identification of high-potency human TLR8 and dual TLR7/TLR8 agonists in pyrimidine-2,4-diamines. J. Med Chem. 60, 2084–2098 (2017).
Cervantes, J. L., Weinerman, B., Basole, C. & Salazar, J. C. TLR8: The forgotten relative revindicated. Cell Mol. Immunol. 9, 434–438 (2012).
Felgner, J. et al. Lipid nanoparticle development for a fluvid mRNA vaccine targeting seasonal influenza and SARS-CoV-2. npj Vaccines 10, 123 (2025).
Jan, S. et al. Multivalent vaccines demonstrate immunogenicity and protect against coxiella burnetii aerosol challenge. Front. Immunol. 14, 1192821 (2023).
Pal, S. et al. Evaluation of four adjuvant combinations, IVAX-1, IVAX-2, CpG-1826+Montanide ISA 720 VG and CpG-1018+Montanide ISA 720 VG, for safety and for their ability to elicit protective immune responses in mice against a respiratory challenge with chlamydia muridarum. Pathogens 12, 863 (2023).
Short, K. K. et al. Co-encapsulation of synthetic lipidated TLR4 and TLR7/8 agonists in the liposomal bilayer results in a rapid, synergistic enhancement of vaccine-mediated humoral immunity. J. Control Release 315, 186–196 (2019).
Cole, S. L. et al. Influenza vaccines using liposomal formulations of toll-like receptor (TLR) 7/8 and 4 agonists as adjuvants. J. Immunol. 204, 245.12 (2020).
Živković, I. et al. Sex bias in mouse humoral immune response to influenza vaccine depends on the vaccine type. Biologicals 52, 18–24 (2018).
Fink, A. L., Engle, K., Ursin, R. L., Tang, W.-Y. & Klein, S. L. Biological sex affects vaccine efficacy and protection against influenza in mice. Proc. Natl. Acad. Sci. 115, 12477–12482 (2018).
Potluri, T. et al. Age-associated changes in the impact of sex steroids on influenza vaccine responses in males and females. npj Vaccines 4, 1–12 (2019).
Chen, J., Deng, J. C. & Goldstein, D. R. How aging impacts vaccine efficacy: known molecular and cellular mechanisms and future directions. Trends Mol. Med. 28, 1100–1111 (2022).
Flanagan, K. L., Fink, A. L., Plebanski, M. & Klein, S. L. Sex and gender differences in the outcomes of vaccination over the life course. Annu. Rev. Cell Dev. Biol. 33, 577–599 (2017).
Cox, R. J. Correlates of protection to influenza virus, where do we go from here? Hum. Vaccin Immunother. 9, 405–408 (2013).
Hirano, T. IL-6 in inflammation, autoimmunity and cancer. Int. Immunol. 33, 127–148 (2021).
Crotty, S. T Follicular helper cell biology: a decade of discovery and diseases. Immunity 50, 1132–1148 (2019).
Alameh, M.-G. et al. Lipid nanoparticles enhance the efficacy of mRNA and protein subunit vaccines by inducing robust T follicular helper cell and humoral responses. Immunity 54, 2877–2892.e7 (2021).
Liao, H.-C. et al. Low-Dose SARS-CoV-2 S-Trimer with an emulsion adjuvant induced Th1-biased protective immunity. Int J. Mol. Sci. 23, 4902 (2022).
Vanni, T. et al. Dose-sparing effect of two adjuvant formulations with a pandemic influenza A/H7N9 vaccine: a randomized, double-blind, placebo-controlled, phase 1 clinical trial. PLoS ONE 17, e0274943 (2022).
Gorse, G. J. et al. A phase 1 dose-sparing, randomized clinical trial of seasonal trivalent inactivated influenza vaccine combined with MAS-1, a novel water-in-oil adjuvant/delivery system. Vaccine 40, 1271–1281 (2022).
Shi, H., Zhang, X. & Ross, T. M. A single dose of inactivated influenza virus vaccine expressing COBRA hemagglutinin elicits broadly-reactive and long-lasting protection. PLoS ONE 20, e0308680 (2025).
Winklmeier, S. et al. Intramuscular vaccination against SARS-CoV-2 transiently induces neutralizing IgG rather than IgA in the saliva. Front. Immunol. 15, 1330864 (2024).
Li, L. et al. Immunisation of ferrets and mice with recombinant SARS-CoV-2 spike protein formulated with Advax-SM adjuvant protects against COVID-19 infection. Vaccine 39, 5940–5953 (2021).
Fulvini, A. A. et al. Gene constellation of influenza A virus reassortants with high growth phenotype prepared as seed candidates for vaccine production. PLoS ONE 6, e20823 (2011).
Brauer, R. & Chen, P. Influenza virus propagation in embryonated chicken eggs. J. Vis. Exp. 97, 52421 (2015).
Ramakrishnan, M. A. Determination of 50% endpoint titer using a simple formula. World J. Virol. 5, 85–86 (2016).
Amanat, F. et al. An in vitro microneutralization assay for SARS-CoV-2 serology and drug screening. Curr. Protoc. Microbiol 58, e108 (2020).
Choi, Y. S. et al. Administration sequence- and formation-dependent vaccination using acid-degradable polymeric nanoparticles with high antigen encapsulation capability. J. Mater. Chem. B 12, 6577–6586 (2024).
Nakajima, R. et al. Protein microarray analysis of the specificity and cross-reactivity of influenza virus hemagglutinin-specific antibodies. mSphere 3 https://doi.org/10.1128/mSphere.00592-18 (2018).
Kastenschmidt, J. M. et al. Influenza vaccine format mediates distinct cellular and antibody responses in human immune organoids. Immunity 56, 1910–1926.e7 (2023).
Assis, R. et al. Distinct SARS-CoV-2 antibody reactivity patterns in coronavirus convalescent plasma revealed by a coronavirus antigen microarray. Sci. Rep. 11, 7554 (2021).
Liu, W.-C., Nachbagauer, R., Krammer, F. & Albrecht, R. A. Assessment of influenza virus hemagglutinin stalk-specific antibody responses. Methods Mol. Biol. 1836, 487–511 (2018).
Gross, F. L., Bai, Y., Jefferson, S. Holiday, C. & Levine, M. Z. Measuring influenza neutralizing antibody responses to A(H3N2) viruses in human sera by microneutralization assays using MDCK-SIAT1 cells. J. Vis. Exp. 129, 56448 (2017).
WHO information for the molecular detection of influenza viruses. https://cdn.who.int/media/docs/default-source/influenza/molecular-detention-of-influenza-viruses/protocols_influenza_virus_detection_feb_2021.pdf.
Gangisetty, O. & Reddy, D. S. The optimization of TaqMan real-time RT-PCR assay for transcriptional profiling of GABA-A receptor subunit plasticity. J. Neurosci. Methods 181, 58–66 (2009).
Jones, K. et al. Vaccine-linked chemotherapy improves benznidazole efficacy for acute chagas disease. Infect. Immun. 86, e00876–17 (2018).