AKS-452 is a CoV-2 protein subunit vaccine based on the Ambifect™ Fc-fusion protein platform. This vaccine is thermostable, low-cost, and has a ‘universal’ booster vaccine capability. It induces a Th1/Th2 mixed immune response in patients against the Receptor Binding Domain (RBD) of the novel coronavirus spike protein.



The vaccine is designed to meet the specific needs of developing countries — low-cost production and little or no refrigeration needed for transport and use. AKS-452 has been shown to be shelf-stable for at least six months at 25° Celsius (77° Fahrenheit) and maintains its potency for one month at 37° Celsius (99° Fahrenheit). This can greatly simplify distribution and is critically important for vaccinating the billions of people not served by current vaccines needing costly cold-chain transportation.

Development status

Akston’s AKS-452 COVID-19 vaccine provides a practical solution to the problem of vaccinating and boosting the immunity of people all over the world against the SARS-CoV-2 virus.

A Phase I trial in the Netherlands showed AKS-452 to be safe and well-tolerated. Most importantly, it produced a 100% seroconversion rate in a 90 ug single-dose regimen, as well as in a 45 ug two dose regimen.

A Phase II study showed a robust overall 98% seroconversion response after either two 45 μg doses (100%), or a single 90 μg dose (96%) in healthy adults at 56 days. These also resulted in robust antibody neutralization of variants, including Delta and Omicron.

A Phase II/III clinical study in India included 1,600 healthy volunteers – 100 in an open-label bridging study and 1,500 in a double-blind, placebo-controlled trial. The results showed no significant safety issues and a 91% seroconversion rate at Day 56. Volunteers in the bridging study had antibody titers that persisted at statistically significant high levels through six months, with serum taken from them showing protection against variants of concern.

The results have been submitted for Emergency Use Authorization (EUA) in India as a prime vaccine. Other clinical studies are designed to support its approval for use as a booster shot to itself and other approved vaccines. 

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