# Final Preclinical Testing and Formulation of a Scalable, Live-attenuated SARS-CoV-2 Vaccine

> **NIH NIH R44** · CODAGENIX, INC. · 2021 · $999,267

## Abstract

PROJECT SUMMARY
There is a critical need for effective SARS-CoV-2 vaccines that can be rapidly produced at large scale. Given
our rudimentary understanding of the immunological responses to the virus, a vaccine that engenders a
broad-based response (innate, humoral, and cellular), is particularly appealing. Further, with little or no a
priori knowledge of key immunological targets, a vaccine that can present all of a virus’ antigens to the host is
ideal. In response, using its unique computational algorithm, Codagenix has designed and completed initial
pre-clinical testing of an intranasal, live-attenuated SARS-CoV-2 vaccine, CDX-005, that 1) activates innate,
humoral, and cellular immune responses, 2) presents every viral antigen in its natural conformation to the
inoculated host, and 3) will be inexpensive, fast, and easy to produce at scale. This is the only LAV being
developed for the US market. The vaccine grows robustly in fully characterized GMP cells and pre-clinical
data suggest that a single, low, intranasal dose in the range of 104-106 PFU will be protective. Pre-clinical
testing in Syrian Golden hamsters demonstrated the safety, attenuation, and efficacy of CDX-005 in vivo, and a
Phase I clinical trial will be beginning in the UK in 2020 using product manufactured overseas. Our goal is to
produce and distribute the CDX-005 SARS-CoV-2 vaccine in the United States. To this end, Codagenix has
had pre-IND communications with and guidance from the FDA. We propose to complete additional pre-
clinical studies in response to FDA recommendations and to develop a formulation that is stable for extended
periods at 4°C to reduce shipping costs, simplify end-user storage, and make it easier to administer the
vaccine. Accordingly, in Aim 1, we will develop a CDX-005 formulation that is stable for extended periods at
2°-8°C. Starting with our frozen formulation as a base, we will test excipients for their ability to stabilize a
liquid vaccine using forced degradation, accelerated stability testing, and long-term stability testing protocols.
In Aim 2, we will determine the toxicity, immunogenicity, biodistribution, attenuation, and efficacy of late
passage CDX-005 in Syrian Golden hamsters. In preparation for an IND filing, we will 1) assess toxicity by
histopathology and hematology after inoculation with CDX-005, 2) examine CDX-005 immunogenicity by
serum IgG ELISA, plaque reduction neutralization, and Th1/Th2 response by qPCR, 3) determine CDX-005
biodistribution and attenuation by qPCR and TCID50 in tissues and excretions, and 4) assess CDX-005 efficacy
by SARS-CoV-2 challenge. In parallel with the proposed work, we will bring CDX-005 manufacturing
capabilities to the US, conduct a Phase I clinical trial in the UK, and sequence the virus from tissues in these
patients to test for possible reversion. We recognize that other SARS-CoV-2 vaccines may reach the market
before CDX-005. While these will be a tremendous boon short term in the fight against...

## Key facts

- **NIH application ID:** 10255845
- **Project number:** 1R44AI162404-01
- **Recipient organization:** CODAGENIX, INC.
- **Principal Investigator:** Steffen Mueller
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $999,267
- **Award type:** 1
- **Project period:** 2021-05-06 → 2023-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10255845

## Citation

> US National Institutes of Health, RePORTER application 10255845, Final Preclinical Testing and Formulation of a Scalable, Live-attenuated SARS-CoV-2 Vaccine (1R44AI162404-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10255845. Licensed CC0.

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