Nanoparticle vaccine candidate for Covid produces antibodies: Study

Washington, Nov 3 (IANS) An innovative nanoparticle vaccine candidate for the Covid-19 virus produces virus-neutralizing antibodies in mice at levels 10X greater than is seen in people who have recovered from the infections, say researchers.

Designed by scientists at the University of Washington School of Medicine in Seattle, the vaccine candidate has been transferred to two companies for clinical development.

Compared to vaccination with the soluble SARS-CoV-2 Spike protein, which is what many leading Covid-19 vaccine candidates are based on, the new nanoparticle vaccine produced ten times more neutralizing antibodies in mice, even at a six-fold lower vaccine dose.

"We hope that our nanoparticle platform may help fight this pandemic that is causing so much damage to our world. The potency, stability, and manufacturability of this vaccine candidate differentiate it from many others under investigation," said study authors from the University of Washington.

The data, published in the journal Cell, also show a strong B-cell response after immunization, which can be critical for immune memory and a durable vaccine effect.

When administered to a single nonhuman primate, the nanoparticle vaccine produced neutralizing antibodies targeting multiple different sites on the Spike protein.

Researchers say this may ensure protection against mutated strains of the virus, should they arise. The Spike protein is part of the coronavirus infectivity machinery.

The vaccine candidate was developed using structure-based vaccine design techniques invented at UW Medicine.

It is a self-assembling protein nanoparticle that displays 60 copies of the SARS-CoV-2 Spike protein's receptor-binding domain in a highly immunogenic array.

The molecular structure of the vaccine roughly mimics that of a virus, which may account for its enhanced ability to provoke an immune response.

"Hundreds of candidate vaccines for Covid-19 are in development around the world. Many require large doses, complex manufacturing, and cold-chain shipping and storage," the researchers wrote.

"An ultrapotent vaccine that is safe, effective at low doses, simple to produce and stable outside of a freezer could enable vaccination against Covid-19 on a global scale," they noted.

--IANS

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