DNA origami vaccines could be the next leap beyond mRNA

The unprecedented challenges posed by the COVID-19 pandemic catapulted messenger RNA (mRNA) vaccine technology into the global consciousness, fundamentally altering the landscape of infectious disease prevention. On December 8, 2020, a new chapter in medical history began with the administration of the first COVID-19 mRNA vaccine, a milestone that heralded a rapid and effective response to a rapidly spreading pathogen. Within its inaugural year, these innovative vaccines were estimated by researchers, through sophisticated epidemiological modeling, to have averted a staggering 14.4 million deaths worldwide. This profound impact underscored the transformative potential of mRNA platforms, inspiring scientists to broaden their application to a spectrum of other formidable infectious diseases. Clinical trials are now actively underway, investigating mRNA vaccine candidates for pathogens such as the influenza virus, Respiratory Syncytial Virus (RSV), HIV, Zika, Epstein-Barr virus, and even tuberculosis bacteria.

However, despite their undeniable success, the intense scrutiny and real-world deployment of COVID-19 mRNA vaccines have also brought to light several important limitations, underscoring the pressing need for the development of alternative and complementary vaccine strategies. The global scientific community is increasingly recognizing that while mRNA technology represents a monumental leap forward, it is not without its challenges, particularly concerning long-term efficacy, adaptability to evolving pathogens, and logistical hurdles in manufacturing and distribution.

Addressing the Achilles’ Heel of Current Vaccine Strategies

The immune protection conferred by COVID-19 mRNA vaccines, while robust, has been observed to vary significantly among individuals. This variability can be attributed to a confluence of factors, including genetic predispositions, pre-existing immunity from prior infections, and differences in individual immune responses. Furthermore, the longevity of this protection is not indefinite, necessitating booster shots to maintain adequate immunity. This challenge is further compounded by the relentless evolutionary pressure on SARS-CoV-2, which continually generates new variants capable of partially evading existing immune defenses. Variants like Alpha, Delta, and Omicron have demonstrated varying degrees of immune escape, leading to breakthrough infections and necessitating frequent vaccine updates to match the circulating strains. This constant arms race between virus and vaccine places significant strain on public health systems and vaccine developers alike, highlighting the demand for more broadly protective and enduring solutions.

Beyond the immunological complexities, significant practical challenges persist in the production and deployment of mRNA vaccines. The manufacturing process for these vaccines is notoriously intricate and expensive. It involves several highly specialized steps, including the enzymatic synthesis of mRNA, its purification to pharmaceutical standards, and the precise encapsulation of these delicate mRNA molecules within lipid nanoparticles (LNPs). Controlling the exact number of mRNA molecules packaged into each LNP remains a formidable task, impacting consistency and yield.

Perhaps one of the most widely recognized logistical constraints is the stringent cold chain requirement. Vaccines like Pfizer-BioNTech’s BNT162b2 initially required ultra-cold storage at approximately -70°C (-94°F), while Moderna’s mRNA-1273 necessitated storage at -20°C (-4°F). Such extreme temperature requirements pose immense logistical hurdles, particularly in low-resource settings lacking advanced cold storage infrastructure. Maintaining these temperatures across vast supply chains, from manufacturing sites to remote vaccination clinics, incurs substantial costs and operational complexities. Any deviation from the required temperature range can compromise vaccine integrity and efficacy, leading to wastage. Moreover, there is an ongoing need to thoroughly understand and mitigate any potential unintended off-target effects that might arise from the systemic delivery of mRNA or LNPs. Overcoming these multifactorial limitations is paramount to enhancing global preparedness and responsiveness to future infectious disease threats.

DoriVac: A Nanotechnology Breakthrough in Immunization

In pursuit of innovative solutions to these challenges, a pioneering multidisciplinary team—comprising experts from the Wyss Institute at Harvard University, Dana-Farber Cancer Institute (DFCI), and their partner institutions—has embarked on an entirely distinct approach. Their groundbreaking work centers on a novel DNA origami nanotechnology platform named DoriVac. This ingenious platform is engineered to serve a dual function, operating simultaneously as both a vaccine and an integrated adjuvant, thereby eliminating the need for separate immunostimulatory components.

The DoriVac platform leverages the precise self-assembly properties of DNA to construct intricate nanoscale structures. Researchers meticulously designed DoriVac vaccines to target a specific and highly conserved peptide region, known as HR2, located within the spike proteins of several notorious viruses, including SARS-CoV-2, HIV, and Ebola. This strategic targeting of conserved epitopes is crucial, as these regions are less prone to mutation, offering the potential for broader and more durable protection against evolving viral strains. Initial preclinical evaluations in murine models demonstrated that the SARS-CoV-2 HR2 DoriVac vaccine elicited exceptionally strong and comprehensive immune responses. These included robust antibody-driven (humoral) activity, which is vital for neutralizing circulating virus, and potent T cell-driven (cellular) activity, essential for identifying and eliminating infected cells.

Recognizing the inherent limitations of translating findings directly from animal models to human physiology, the team employed an advanced preclinical human model: the Wyss Institute’s cutting-edge microfluidic human Organ Chip technology. This innovative system accurately simulates the complex microenvironment and immunological functions of a human lymph node in vitro. Within this sophisticated system, the SARS-CoV-2 HR2 DoriVac vaccine again generated strong antigen-specific immune responses in human cells, providing compelling evidence for its potential efficacy in humans and bridging a critical gap in vaccine development.

A pivotal comparative study was conducted, directly pitting a DoriVac vaccine—carrying the identical spike protein variant—against established SARS-CoV-2 mRNA vaccines delivered via lipid nanoparticles. In these human models, the DoriVac platform produced a similarly strong immune activation. However, the DNA origami vaccine showcased distinct advantages in terms of stability, significantly simplifying its storage requirements and streamlining its manufacturing processes. These transformative findings, which herald a new era in vaccine design, were rigorously peer-reviewed and subsequently reported in the esteemed scientific journal Nature Biomedical Engineering.

Precision Engineering Immunity: How DoriVac Works

The concept of DoriVac as a DNA nanotechnology-based vaccine platform with broad potential applications was first introduced in 2024 by Dr. William Shih’s pioneering team at the Wyss Institute and Dana-Farber. Dr. Yang (Claire) Zeng, M.D., Ph.D., who spearheaded this monumental effort alongside a dedicated team of collaborators, played a crucial role in demonstrating DoriVac’s unparalleled ability to precisely present immune-stimulating adjuvant molecules to cells at the nanoscale. This exquisite control over molecular presentation is a hallmark of DNA origami technology.

Earlier foundational studies, conducted in tumor-bearing mice, had already showcased the platform’s potency, revealing that DoriVac vaccines generated significantly stronger immune responses compared to versions lacking the unique DNA origami structure. The DoriVac vaccines are ingeniously constructed from tiny, self-assembling square DNA nanostructures. These structures are meticulously designed such that one side precisely displays adjuvant molecules, arranged at carefully controlled nanometer distances, while the opposite side presents selected antigens, which can be peptides or proteins derived from tumors or pathogens. This modular design allows for unprecedented control over vaccine composition and the ability to program immune recognition at a molecular level.

"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," stated Dr. William Shih, co-corresponding author and Wyss Institute Core Faculty member, whose group pioneered this novel vaccine concept. Dr. Shih, also a Professor at Harvard Medical School and DFCI, emphasized, "Our study demonstrates DoriVac’s versatility and potential by taking a close look at the immune changes that are required to fight infectious viruses."

Dr. Zeng, a first and co-corresponding author on the new study and now cofounder and CEO/CTO of DoriNano, leading the translation of this technology into clinical applications, recounted the pivotal moment for DoriVac’s pivot to infectious diseases: "While we were developing the platform for cancer applications, the COVID-19 pandemic was still moving with full force. So, the question quickly arose whether DoriVac’s superior adjuvant activity could also be leveraged in infectious disease settings."

To rigorously explore this compelling idea, Dr. Zeng and co-first author Dr. Olivia Young, a former graduate student in Dr. Shih’s group, initiated a collaborative effort with Dr. Donald Ingber’s team at the Wyss Institute. Dr. Ingber’s group is renowned for its innovative approach to antiviral research, utilizing AI-driven and multiomics strategies in conjunction with sophisticated microfluidic human Organ Chip systems. Working closely with co-first author Dr. Longlong Si, a former postdoctoral researcher in Dr. Ingber’s lab, the researchers meticulously developed DoriVac vaccines specifically targeting SARS-CoV-2, HIV, and Ebola, all presenting the conserved HR2 peptides.

Dr. Zeng elaborated on the encouraging outcomes of these initial murine studies: "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." She further explained, "We found that the numbers of antibody-producing B cells, activated antigen-presenting dendritic cells (DCs), and antigen-specific memory and cytotoxic T cell types that are vital for long-term protection were all increased, especially in the case of the SARS-CoV-2 HR2." This comprehensive activation of multiple immune arms is crucial for robust and sustained protection against pathogens.

From Bench to Bedside: Rigorous Preclinical Validation

A persistent and significant hurdle in vaccine development lies in the translational gap between preclinical animal studies and human clinical outcomes. Immune responses observed in mice, while informative, often do not fully replicate the complexities of the human immune system, a discrepancy that has historically led to the failure of many promising treatments during later-stage clinical trials. To overcome this critical challenge and enhance the predictive accuracy of their research, the DoriVac team strategically employed a human lymph node-on-a-chip (human LN Chip) system. This advanced microfluidic platform is meticulously designed to mimic key aspects of the human immune system, providing a more physiologically relevant testing ground.

This groundbreaking system, significantly advanced by co-first author Min Wen Ku and co-corresponding author Dr. Girija Goyal, Ph.D., Director of Bioinspired Therapeutics at the Wyss Institute, proved instrumental in validating the DoriVac platform’s potential for human application. The human LN Chip experiments demonstrated that the SARS-CoV-2-HR2 DoriVac vaccine effectively activated human dendritic cells (DCs) and substantially increased their production of inflammatory cytokines, crucial signaling molecules for initiating immune responses, when compared to origami-free components. Critically, it also led to an increase in the number of CD4+ and CD8+ T cells, which possess multiple protective functions, ranging from helping B cells produce antibodies to directly killing infected cells. These findings provided strong further support for the platform’s potential utility in humans.

"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," remarked Dr. Donald Ingber, M.D., Ph.D., co-corresponding author, who is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children’s Hospital, and the Hansjörg Wyss Professor of Biologically Inspired Engineering at Harvard John A. Paulson School of Engineering and Applied Sciences. He emphasized the synergistic power of their approach: "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 use of human organ-on-a-chip technology significantly de-risks the early stages of vaccine development, potentially accelerating the journey from lab to clinic.

DoriVac Versus mRNA: A Head-to-Head Comparison

To firmly establish DoriVac’s standing against the current gold standard, the researchers undertook a direct comparative study. Under the leadership of Dr. Zeng and co-author Qiancheng Xiong, a DoriVac vaccine presenting the full SARS-CoV-2 spike protein was evaluated head-to-head against commercially available Moderna and Pfizer/BioNTech mRNA lipid nanoparticle (LNP) vaccines, both of which encode the identical spike protein.

Employing a standard booster immunization approach in mice, the results were highly encouraging: both vaccine types produced remarkably similar antiviral T cell and antibody-producing B cell responses. This parity in immune activation is a critical indicator of DoriVac’s potential to deliver comparable protective immunity to established mRNA vaccines.

"This underscored DoriVac’s potential as a DNA nanotechnology-enabled, self-adjuvanted vaccine platform," Dr. Shih commented, highlighting the platform’s inherent efficacy. He continued, "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 implications of these practical advantages are profound. Eliminating the need for ultra-cold storage dramatically simplifies logistics, reduces infrastructure costs, and opens pathways for vaccine distribution to the most remote and underserved populations globally, directly addressing issues of vaccine equity. Furthermore, the potential to streamline manufacturing processes could lead to more efficient, scalable, and cost-effective production, mitigating the supply chain bottlenecks experienced during the COVID-19 pandemic. Recent studies conducted by DoriNano, the company translating this technology, have also demonstrated that DoriVac exhibits a promising safety profile, a crucial factor for clinical translation and regulatory approval.

The Broader Implications: Reshaping Global Health Preparedness

The emergence of the DoriVac platform represents more than just an incremental improvement in vaccine technology; it signifies a potential paradigm shift in how the world approaches infectious disease prevention and pandemic preparedness. The inherent stability of DNA origami structures, which do not require the ultra-cold storage characteristic of mRNA vaccines, is a game-changer for global health equity. In many parts of the world, particularly in developing nations, the lack of robust cold chain infrastructure has been a significant barrier to effective vaccine distribution. DoriVac’s room-temperature stability could enable widespread access, ensuring that life-saving vaccines can reach every corner of the globe without degradation, thereby bridging a critical gap in global health disparities.

Moreover, the simplified manufacturing process for DNA origami vaccines holds the promise of decentralizing vaccine production. Current mRNA vaccine manufacturing relies on highly specialized facilities and expertise, concentrating production in a few regions. A more straightforward and potentially less capital-intensive manufacturing pathway for DoriVac could empower more countries to produce their own vaccines, fostering greater self-sufficiency and resilience in the face of future outbreaks. This would reduce global reliance on a limited number of manufacturers, enhancing overall pandemic response capabilities and vaccine sovereignty.

The strategic targeting of conserved viral regions, such as the HR2 peptide, positions DoriVac as a strong candidate for developing broadly protective vaccines—often termed "variant-proof" vaccines. This approach could offer longer-lasting protection against a wider array of viral strains, reducing the need for frequent vaccine updates and booster campaigns, which are both costly and logistically challenging. The platform’s modular design also suggests its immense versatility, allowing for rapid adaptation to new pathogens or emerging variants. This adaptability is paramount for swift responses to novel threats, providing a crucial tool in the arsenal against future pandemics.

Beyond infectious diseases, DoriVac’s initial success in oncology applications hints at its broader therapeutic potential. The ability to precisely present antigens and adjuvants to modulate immune responses could unlock new avenues for treating various conditions, including autoimmune diseases and cancer. The robust and balanced immune responses—both humoral and cellular—observed with DoriVac are particularly promising for complex diseases that require multifaceted immune activation for effective control.

The Road Ahead: Next Steps for DoriVac

While the preclinical data for DoriVac are compelling and highly encouraging, the journey from laboratory innovation to widespread clinical application is long and rigorously regulated. The immediate next steps for DoriVac will involve comprehensive large animal studies to further assess safety, immunogenicity, and efficacy in models that more closely mimic human physiology. Following successful completion of these preclinical stages, the platform would then advance to human clinical trials, beginning with Phase 1 studies to evaluate safety and dose-response in healthy volunteers, followed by larger Phase 2 and Phase 3 trials to confirm efficacy and monitor for any rare adverse events.

The establishment of DoriNano, led by Dr. Yang (Claire) Zeng, signifies a committed effort to translate this groundbreaking technology into clinically viable applications. The company’s focus on demonstrating DoriVac’s promising safety profile is a critical component of its developmental strategy, essential for gaining regulatory approvals from agencies such as the FDA and EMA. The vision is clear: to leverage DNA origami nanotechnology to create a new generation of vaccines that are not only highly effective but also universally accessible, stable, and easier to manufacture, ultimately enhancing global health security for decades to come.

This ambitious research has been made possible through the generous support of various institutions and funding bodies, 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). The collaborative spirit and interdisciplinary expertise of all involved researchers—Sylvie Bernier, Hawa Dembele, Giorgia Isinelli, Tal Gilboa, Zoe Swank, Su Hyun Seok, Anjali Rajwar, Amanda Jiang, Yunhao Zhai, LaTonya Williams, Caleb Hellman, Chris Wintersinger, Amanda Graveline, Andyna Vernet, Melinda Sanchez, Sarai Bardales, Georgia Tomaras, Ju Hee Ryu, and Ick Chan Kwon—have been instrumental in bringing this transformative scientific endeavor to fruition.