In August 2023 the Access to Advanced Health Institute (AAHI) announced that it had received an $18 million award from the NIH in support of its efforts to develop a temperature stable, single-dose vaccine candidate against chikungunya. The award is intended to support development, preclinical development, and human clinical evaluation of a vaccine to meet the “increasingly urgent need” for a “reliable, abundant supply” of a chikungunya vaccine.
Revolutionary RNA technologies
The technology used at AAHI does not require the “complex manufacturing techniques” or deep cold-chain storage that are associated with traditional live-attenuated vaccines. This is because it binds RNA to the outside of a proprietary nanostructured lipid carrier (NLC) delivery vehicle, which protects the RNA, safely delivering it to cells.
The candidate will be a lyophilised, live-attenuated RNA vaccine candidate, delivering the full-length RNA genome of a weakened version of the virus complexed to the NLC. The vaccine formulation is intended to be stable at ambient temperatures for up to several months and in refrigerated settings for at least a year.
Dr Emily Voigt, Principal Scientist, RNA Platform Lead, and Co-Principal Investigator for the award, hopes that the project will “demonstrate the use of RNA vaccine technology” in avoiding “classic manufacturing challenges”.
“Additionally, our RNA vaccine platform uses standard manufacturing equipment and techniques employed by vaccine manufacturers worldwide that are easy to tech transfer and scale, unlike current mRNA vaccine technology.”
This could have the benefit of increased availability and access and is, to the team’s knowledge, the first attempt to advance an RNA-launched live-attenuated vaccine candidate to the clinic.
Building on strong foundations
The 5-year project expands on previous research that demonstrated that a liquid presentation of the live-attenuated chikungunya RNA vaccine elicited strong immune responses in animals after a single dose. When the vaccinated animals were challenged with the virus they were protected from mortality and joint swelling.
If this vaccine development proves successful, other RNA-delivered, live-attenuated vaccine candidates could be investigated, particularly against viruses that “disproportionately affect poor and marginalised areas”.