By Budi Oetomo Narendra 
The global landscape of vaccine development is undergoing a significant transformation, propelled by the urgent demands of the recent COVID-19 pandemic. While messenger RNA (mRNA) vaccines undeniably marked a monumental scientific triumph, rapidly deployed and preventing an estimated 14.4 million deaths worldwide during their first year following the inaugural administration on December 8, 2020, their success has also illuminated inherent challenges within current vaccine strategies. These insights have spurred a multidisciplinary team from the Wyss Institute at Harvard University, Dana-Farber Cancer Institute (DFCI), and their partner institutions to unveil a novel approach: the DNA origami nanotechnology platform dubbed DoriVac, which promises to overcome critical limitations in vaccine performance, production, and distribution.
The mRNA Revolution and Its Evolving Challenges
The COVID-19 pandemic thrust mRNA vaccine technology into the global spotlight, showcasing its unprecedented speed of development and high efficacy against the initial SARS-CoV-2 strains. This breakthrough swiftly led scientists to explore mRNA platforms for a wide array of other infectious diseases, with ongoing clinical trials targeting prevalent pathogens such as influenza virus, Respiratory Syncytial Virus (RSV), HIV, Zika virus, Epstein-Barr virus, and tuberculosis bacteria. The adaptability and rapid prototyping capabilities of mRNA technology initially seemed poised to revolutionize vaccine development across the board.
However, subsequent real-world experience and extensive research into COVID-19 mRNA vaccines have also revealed important limitations that necessitate the exploration of alternative strategies. One primary concern is the variability in immune protection generated by these vaccines, which can differ significantly from person to person. Furthermore, the durability of this protection is not indefinite, often waning over time. This challenge is compounded by the relentless evolutionary pressure on SARS-CoV-2, which consistently produces new variants capable of partially evading existing immune defenses, thereby necessitating frequent vaccine updates and booster campaigns. Such an arms race against a rapidly mutating pathogen places immense strain on public health resources and infrastructure.
Beyond immunological considerations, practical hurdles in the manufacturing and distribution of mRNA vaccines have also become apparent. The production process for mRNA vaccines is inherently complex and expensive, requiring specialized facilities and stringent quality control measures. A particularly difficult aspect involves precisely controlling the packaging of mRNA molecules into lipid nanoparticles (LNPs), which are crucial for vaccine delivery. Moreover, the stringent cold chain requirements for mRNA vaccines—often demanding ultra-cold storage at temperatures as low as -70°C for some formulations (e.g., Pfizer-BioNTech) or deep-freeze conditions at -20°C for others (e.g., Moderna)—present formidable logistical challenges. These requirements complicate distribution, especially in low-resource settings or regions with inadequate cold chain infrastructure, hindering equitable global access. There are also ongoing studies into the potential for unintended off-target effects, although generally rare and mild, that warrant continuous research and improvement. Overcoming these multifaceted limitations is paramount for enhancing global preparedness and response capabilities for future infectious disease threats.
DoriVac: A Paradigm Shift in Vaccine Design
In response to these critical challenges, a collaborative team of researchers led by William Shih, Ph.D., a Wyss Institute Core Faculty member and Professor at Harvard Medical School and DFCI, and Yang (Claire) Zeng, M.D., Ph.D., who spearheaded the effort, introduced DoriVac as a novel solution. This DNA origami nanotechnology platform functions not only as a vaccine antigen delivery system but also as an intrinsic adjuvant, significantly streamlining vaccine design. The core innovation lies in its precise, self-assembling nanostructures, which offer unparalleled control over vaccine composition and the ability to program immune recognition at a molecular level within targeted immune cells.
The DoriVac platform is built from tiny, self-assembling square DNA nanostructures. One side of this precisely engineered nanostructure displays immune-stimulating adjuvant molecules, arranged at carefully controlled nanometer distances to optimize immune cell activation. The opposite side presents selected antigens, which can be peptides or proteins derived from pathogens or tumor cells. This modular design allows for exceptional flexibility and precision in vaccine construction, a distinct advantage over more traditional or even mRNA-LNP vaccine formats where adjuvant effects might be less precisely controlled or require separate components.
The initial conceptualization of DoriVac by Shih’s team in 2024 (as reported in other studies) demonstrated its broad potential, particularly in cancer applications. Earlier studies in tumor-bearing mice showcased that these DNA origami-based vaccines generated significantly stronger immune responses compared to versions lacking the DNA origami structure, highlighting the platform’s intrinsic adjuvant capabilities. As the COVID-19 pandemic raged, the question naturally arose whether DoriVac’s superior adjuvant activity could be harnessed to combat infectious diseases, a query that drove the current research, as noted by Dr. Zeng, now co-founder and CEO/CTO of DoriNano, a company focused on translating this technology into clinical applications.
Preclinical Validation: From Mouse Models to Human Organ Chips
To explore DoriVac’s potential in infectious disease, Dr. Zeng and co-first author Olivia Young, Ph.D., a former graduate student in Shih’s group, collaborated with Donald Ingber’s team at the Wyss Institute. Ingber’s group is renowned for its antiviral innovation, employing AI-driven and multiomics approaches alongside sophisticated microfluidic human Organ Chip systems. Together with co-first author Longlong Si, Ph.D., a former postdoctoral researcher in Ingber’s lab, they developed DoriVac vaccines targeting a conserved peptide region (HR2) found in the spike proteins of several highly pathogenic viruses, including SARS-CoV-2, HIV, and Ebola. Targeting such conserved antigens is a strategic move, aiming to elicit broader and potentially longer-lasting protection against viral variants.
The initial phase of validation involved preclinical studies in mice. The SARS-CoV-2 HR2 DoriVac vaccine successfully triggered robust immune responses, encompassing both antibody-driven (humoral) and T cell-driven (cellular) activity. Dr. Zeng elaborated on these encouraging observations, stating, "Our analysis of the immune responses provoked by these first DoriVac vaccines in mice led to several encouraging observations, including significantly greater and broader activation of humoral and cellular immunity across a range of relevant immune cell types than what the origami-free antigens and adjuvants could produce." Specifically, the research found an increase in the numbers of antibody-producing B cells, activated antigen-presenting dendritic cells (DCs), and antigen-specific memory and cytotoxic T cell types, all crucial components for effective, long-term immune protection. The SARS-CoV-2 HR2 vaccine, in particular, demonstrated a pronounced boost in these critical immune cell populations.
A significant hurdle in vaccine development is the often-observed discrepancy between immune responses in animal models and humans, which can lead to the failure of promising candidates during clinical trials. To bridge this gap and enhance the predictability of human outcomes, the research team utilized the Wyss Institute’s advanced microfluidic human Organ Chip technology, specifically a human lymph node-on-a-chip (human LN Chip). This innovative in vitro system accurately mimics key aspects of the human immune system, providing a more relevant testing ground.
Under the guidance of co-first author Min Wen Ku and co-corresponding author Girija Goyal, Ph.D., Director of Bioinspired Therapeutics at the Wyss Institute, the human LN Chip experiments yielded compelling results. The SARS-CoV-2-HR2 DoriVac vaccine activated human DCs and significantly increased their production of inflammatory cytokines compared to origami-free components. Crucially, it also led to an increased number of CD4+ and CD8+ T cells with multiple protective functions, further bolstering the platform’s potential for human application. Dr. Ingber highlighted the profound impact of this technology, stating, "The predictive capabilities of human LN Chips gave us an ideal testing ground for DoriVac vaccines and the induced, antigen-specific immune cell profiles and activities very likely reflect those that would occur in human recipients of the vaccines. This convergence of technologies enabled us to dramatically raise the chances of success for a new class of vaccines and create a new testbed for future vaccine developments." This innovative approach provides a powerful tool for de-risking vaccine candidates before expensive and time-consuming human trials.
Head-to-Head with mRNA: A Promising Comparison
To directly assess DoriVac’s performance against the current gold standard, the researchers conducted a head-to-head comparison with established mRNA vaccines. Led by Dr. Zeng and co-author Qiancheng Xiong, the team evaluated a DoriVac vaccine designed to present the full SARS-CoV-2 spike protein. This was directly compared against commercially available Moderna and Pfizer/BioNTech mRNA lipid nanoparticle (LNP) vaccines that encode the identical spike protein.
In a standard booster regimen administered to mice, both DoriVac and the mRNA-LNP vaccines produced similarly strong antiviral T cell and antibody-producing B cell responses. This finding is profoundly significant, demonstrating that DoriVac can elicit immune responses comparable in strength and breadth to the highly effective mRNA vaccines.
However, the DoriVac platform offers several distinct advantages that address the key limitations of mRNA-LNP vaccines. Dr. Shih emphasized these critical benefits: "This underscored DoriVac’s potential as a DNA nanotechnology-enabled, self-adjuvanted vaccine platform. But DoriVac vaccines have a number of other advantages: they don’t have the same cold-chain requirements as mRNA-LNP vaccines do and thus could be distributed much more effectively, especially in under-resourced regions; and they could overcome some of the enormous manufacturing complexities of LNP-formulated vaccines, to name two major ones." The elimination of ultra-cold storage requirements is a game-changer for global vaccine equity, potentially allowing for much wider and easier distribution in areas lacking advanced logistical infrastructure. Furthermore, the simplified manufacturing process for DoriVac could reduce production costs and accelerate supply chains, making vaccines more accessible and affordable on a global scale. Recent studies conducted by DoriNano have also indicated that DoriVac exhibits a promising safety profile, an essential factor for any new vaccine technology.
Broader Impact and Future Implications
The implications of the DoriVac platform extend far beyond SARS-CoV-2. Its demonstrated versatility and robust immune activation suggest a broad potential for application against other infectious diseases currently targeted by mRNA vaccine efforts, including influenza, RSV, HIV, Zika, Epstein-Barr virus, and tuberculosis. Moreover, the platform’s origins in cancer research mean it holds promise for novel immunotherapies against various malignancies.
The ability to precisely control antigen presentation and adjuvant delivery at the nanoscale, coupled with enhanced stability and simplified manufacturing, positions DoriVac as a critical tool for future pandemic preparedness. A vaccine platform that is stable at ambient temperatures, easier to produce, and capable of eliciting strong, broad immune responses could fundamentally alter the global response to emerging pathogens. It offers a path toward more equitable vaccine distribution, ensuring that effective protection is not limited by a region’s economic or logistical capabilities.
The significant backing for this research, evidenced by funding from diverse sources including the Director’s Fund and Validation Project program of the Wyss Institute, the Claudia Adams Barr Program at DFCI, the National Institutes of Health (U54 grant CA244726-01), the US-Japan CRDF global fund (grant R-202105-67765), the National Research Foundation of Korea (grants MSIT, RS-2024-00463774, RS-2023-00275456), the Intramural Research Program of the Korea Institute of Science and Technology (KIST), and the Bill and Melinda Gates Foundation (INV-002274), underscores the high expectations for DoriVac’s clinical translation and global health impact.
As Dr. Shih aptly summarized, "With the DoriVac platform, we have developed an extremely flexible chassis with a number of critical advantages, including an unprecedented control over vaccine composition, and the ability to program immune recognition in targeted immune cells on a molecular level to achieve better responses." This sentiment is echoed by Dr. Zeng’s leadership in DoriNano, signaling a determined push to bring this transformative technology from the lab to patients.
The DoriVac platform represents a significant leap forward in vaccine technology, combining the high efficacy observed with modern vaccine approaches with enhanced practicality and accessibility. By addressing the critical limitations of current mRNA vaccines, particularly concerning cold chain requirements and manufacturing complexity, this DNA origami-based solution could usher in a new era of global health preparedness, offering a more robust, adaptable, and equitable defense against infectious disease threats worldwide. The findings, published in Nature Biomedical Engineering, mark a pivotal moment in the ongoing quest for superior vaccine solutions.