US-based biotechnology firm Novavax has started enrolling participants in a Phase I/II clinical trial of its Covid-19 vaccine candidate, NVX‑CoV2373, in Australia.

Developed using the company’s nanoparticle technology, NVX‑CoV2373 is engineered from the genetic sequence of SARS‑CoV‑2.

It is designed to produce antigen obtained from the coronavirus spike (S) protein and contains the company’s Matrix-M adjuvant to boost the immune response and trigger high neutralising antibody levels.

In preclinical studies, the vaccine candidate showed high immunogenicity and high levels of neutralising antibodies. Based on these findings, NVX‑CoV2373 is expected to be highly immunogenic in humans.

Novavax president and CEO Stanley Erck said: “Administering our vaccine in the first participants of this clinical trial is a significant achievement, bringing us one step closer toward addressing the fundamental need for a vaccine in the fight against the global Covid‑19 pandemic.”

The Phase I/II trial comprises two parts. The Phase I part is a randomised, observer-blinded, placebo-controlled study assessing the immunogenicity and safety of the vaccine candidate, adjuvanted with Matrix‑M, as well as unadjuvanted.

It is recruiting around 130 healthy participants aged 18 to 59 years at two sites in Australia.

Preliminary immunogenicity and safety data from the Phase I portion are expected in July this year. If promising, the Phase II part will be initiated in several countries, including the US.

The Phase II portion will study immunity, safety and Covid‑19 disease reduction in a wider age range. The trial is being supported by up to $384m funding from the Coalition for Epidemic Preparedness Innovations (CEPI).

CEPI CEO Dr Richard Hatchett said: “Entering clinical trials is an important step on the path to delivering a safe, effective and globally accessible vaccine against Covid-19.

“Vaccines provide our best hope of permanently defeating this pandemic, so it is encouraging to see rapid progress being made in the development of Novavax’ vaccine candidate.”

Hatchett added that CEPI’s investment in Novavax enables simultaneous manufacturing with the clinical development of the vaccine.