A $3 Million Bet on RNA to End Tuberculosis, the World’s Deadliest Plague

SAN DIEGO, CA – June 19, 2026 – A grant of approximately $3 million may seem like a small step against a disease that claims over a million lives each year. But when the Bill & Melinda Gates Foundation awarded this sum to San Diego-based Replicate Bioscience, it signaled a significant stride in one of modern medicine’s most urgent quests: the development of a truly effective vaccine for tuberculosis (TB).

This grant, the third awarded to the company by the foundation, is earmarked to accelerate the development of a TB vaccine using Replicate's pioneering self-replicating RNA (srRNA) technology. More than just a financial transaction, this partnership represents a calculated fusion of cutting-edge science and a deep-seated commitment to global health equity, aiming to finally turn the tide on a centuries-old scourge.

A New Weapon in an Old War

Tuberculosis, a contagious airborne disease caused by Mycobacterium tuberculosis, remains the world’s leading infectious killer, surpassing even COVID-19 in 2023. It disproportionately devastates low- and middle-income countries, where limited resources and co-infections like HIV create a perfect storm for transmission. Annually, an estimated 10 million people fall ill, and millions of cases go undiagnosed, fueling the silent pandemic.

The world is not without a defense, but it is an antiquated one. The Bacillus Calmette-Guérin (BCG) vaccine, developed in 1921, is administered to millions of infants and provides moderate protection against severe forms of TB in children. Its critical failing, however, is its inability to consistently prevent pulmonary TB in adolescents and adults—the very populations that drive community transmission. This gap has left the world vulnerable, a reality made more perilous by the rise of multidrug-resistant TB (MDR-TB), which renders standard treatments ineffective.

The World Health Organization has estimated that a new vaccine for adolescents and adults that is just 50% effective could prevent 76 million new TB cases and 8.5 million deaths by 2050. The need is not just urgent; it is a global imperative. This is the gap that Replicate Bioscience, backed by the Gates Foundation, is aiming to fill.

The Promise of Self-Replicating RNA

At the heart of this new effort is Replicate’s novel self-replicating RNA (srRNA) platform. While the world became familiar with messenger RNA (mRNA) technology during the COVID-19 pandemic, srRNA represents a potential next-generation advancement. Where conventional mRNA delivers a fixed set of instructions for a cell to produce an antigen, srRNA includes an additional instruction: make more copies of yourself. This self-amplification allows for a much smaller initial dose to generate a larger, more sustained production of the target antigen inside the body.

The potential benefits are profound. A lower dose translates directly to lower manufacturing costs per vaccine, a critical factor for ensuring affordability and widespread access in resource-limited settings. Furthermore, the sustained antigen expression is designed to provoke a more powerful and durable immune response, including the T-cell activity that is believed to be essential for fighting a complex intracellular pathogen like the TB bacterium.

Replicate has already produced promising clinical data for its platform. In a Phase I trial for its srRNA rabies vaccine, the company reported achieving protective levels of immunity at doses lower than any other publicly reported RNA vaccine. This result provided crucial validation for the low-dose potential of the technology.

“Clinical data from our srRNA rabies vaccine program support the potential of this platform to induce immune responses at low doses,” said Nathaniel Wang, PhD, Chief Executive Officer of Replicate. “We look forward to applying these learnings to the development of TB vaccine candidates with the goal of improving access for populations most affected by TB.”

A Partnership Forged for Global Access

This grant is defined as much by its terms as by its dollar amount. The funding is subject to the Gates Foundation’s “humanitarian licensing terms,” a core component of its Global Access Commitment. This is not mere legalese; it is a powerful mechanism designed to ensure that the fruits of philanthropic investment reach those who need them most.

These terms effectively grant the foundation a non-exclusive, royalty-free license to ensure the vaccine, if successful, is made available and affordable in developing countries. It’s a safeguard against the market dynamics that often price life-saving innovations out of reach for the world’s poorest populations. This approach aligns with the foundation's broader strategy, which has seen it invest hundreds of millions into TB research, including a recent $550 million pledge with Wellcome for a late-stage trial of another TB vaccine candidate.

For Replicate Bioscience, accepting these terms aligns its corporate mission with a humanitarian one. “This grant from the foundation will support our mission of ensuring vaccine accessibility for global populations to combat devastating infectious diseases,” Wang affirmed.

Building a Pipeline for Global Health

The TB grant is not an isolated project but the latest pillar in Replicate Bioscience’s broader strategy to build a global health powerhouse. The company has also received Gates Foundation funding to develop srRNA vaccine candidates for HIV and malaria, two other diseases that inflict a heavy toll on low-income nations. This trifecta of grants positions the company and its srRNA platform at the forefront of tackling some of the most challenging infectious diseases of our time.

Beyond its work with the Gates Foundation, Replicate has forged a key partnership with Instituto Butantan, a leading Brazilian biomedical center, to develop and commercialize its rabies vaccine in Latin America. This collaboration provides a crucial pathway for regional manufacturing and distribution, demonstrating a practical model for getting its technology into the hands of at-risk populations.

Funded by life sciences venture firm Apple Tree Partners, Replicate is executing a dual strategy: advancing a robust pipeline of therapeutics while leveraging strategic partnerships to address critical global health needs. The modest $3 million grant for TB is a catalyst, enabling the early-stage work necessary to de-risk the program and attract the much larger investments required for late-stage clinical trials. It is a calculated investment in a technology that could one day provide the world with the tool it has needed for over a century to finally end the TB epidemic.