Phase 1 clinical evaluation to assess safety and immunogenicity of CodaVax™-RSV in healthy pediatric populations

In previous Phase 1 study in older adults, CodaVax-RSV was well tolerated and both mucosal and cellular immune responses were observed

Farmingdale, N.Y., June 1, 2022 – Codagenix Inc., a clinical-stage synthetic biology company with a rational virus design platform for viral vaccines and immuno-oncology therapeutics, today announced that the U.S. Food and Drug Administration (FDA) has approved the Investigational New Drug (IND) application for CodaVaxTM-RSV, an intranasal, live-attenuated vaccine candidate, for the prevention of respiratory syncytial virus (RSV) infection in healthy infants and toddlers. RSV is an acute respiratory infection that is the leading cause of hospitalization for young children.

With this FDA clearance, the company plans to initiate a Phase 1 study of vaccine safety and immunogenicity against RSV in healthy children aged six months to five years. This builds upon a Phase 1 study of CodaVax-RSV in adults 55-75 years old, which achieved its primary safety endpoint and elicited strong anti-RSV-specific cellular immune responses. Deficiency in cellular immunity is suspected to contribute to severe RSV disease in elderly adults1.

Codagenix’s CodaVax-RSV vaccine includes hundreds of strategic genomic modifications that slow viral replication, resulting in a genetically stable, attenuated vaccine virus that includes all RSV proteins as antigens. Preclinical data in animal models, including primates, demonstrated that CodaVax-RSV was significantly attenuated compared to natural (or, wild type) RSV, capable of eliciting neutralizing antibody and cellular immune responses and protective against wild type challenge.

“Despite decades of research, there are no approved vaccines that protect against RSV, the leading cause of hospitalization for children below the age of five2—in large part due to a limited focus on antibody-inducing vaccines,” said J. Robert Coleman, Co-Founder and Chief Executive Officer of Codagenix. “Like CoviLivTM, our COVID-19 candidate, CodaVax-RSV is an intranasally administered vaccine designed to provide broad systemic and mucosal immunity via a differentiated approach that allows for the induction of both antibodies and cellular immunity. We are eager to advance CodaVax-RSV into further clinical evaluation as a promising, readily scalable solution to protect our most vulnerable populations worldwide.”

According to the National Institutes of Health, in the United States, nearly all children become infected with RSV by age two, with 75,000 to 125,000 needing hospitalization each year. Globally, RSV affects an estimated 64 million people and causes 160,000 deaths each year. Infants, older adults and adults with chronic medical conditions are more susceptible to severe RSV infections requiring hospitalization.

“RSV causes incredible suffering to children and their families worldwide, and development of a pediatric RSV vaccine is a top World Health Organization priority.  Live- attenuated vaccines for RSV are preferred for children because antibody-focused RSV vaccines may lead to paradoxical increased risk of severe disease,” said Sybil Tasker, M.D., M.P.H., Chief Medical Officer of Codagenix. “Unfortunately, previous live-attenuated RSV vaccine candidates were not well tolerated due to genetic instability and risk of reversion to wild type phenotype. CodaVax-RSV is extremely stable owing to the hundreds of intentionally placed edits that result in an effectively insurmountable barrier against wild type reversion. This genetic stability combined with the preclinical efficacy and adult Phase 1 safety data suggest CodaVax RSV may be a viable tool to address this important global public health priority.”

CodaVax-RSV, and all Codagenix vaccines, are designed using a proprietary and exclusive human codon-deoptimization platform. The technology enables the synthesis of rationally attenuated vaccines that are non-pathogenic yet able to generate a robust cellular and antibody immune response that mimics natural infection, effectively balancing safety, immunogenicity and manufacturability. 

About Codagenix, Inc.

Codagenix is a clinical-stage biotechnology company leading a new era of live vaccines and viral therapeutics. The company’s breakthrough platform brings together live-attenuated virus design with cutting-edge codon deoptimization for powerful synthetic biology-based solutions to take on our biggest threats in infectious disease, cancer and animal health. Codagenix was founded based on technology developed in the laboratory of National Academy of Science member Dr. Eckard Wimmer at Stony Brook University; is supported by Adjuvant Capital, TopSpin Partners, and Euclidean Capital; and has ongoing research and license programs with various federal agencies. For more information, visit

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1 Clin Vaccine Immunol 2013 Feb;20(2):239-247

2 Science. 2013 Nov 1; 342(6158): 592–598.