Chinese scientists have developed a candidate COVID-19 vaccine based on mosaic nanoparticles that can protect against infections of COVID-19 variants.
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Scientists from Sun Yat-sen University, the First Affiliated Hospital of Guangzhou Medical University, and the Guangdong Provincial Center for Disease Control and Prevention have designed the quadrivalent mosaic nanoparticle vaccine comprising advanced proteins from the prototype of SARS-CoV-2 and three major variants, including Alpha, Beta and Gamma.
The virus spike protein is known to play an essential role in viral attachment and fusion with the host cell, and therefore the majority of antibodies that neutralize viral infection target the spike protein.
However, mutations of viral variants located on the spike protein largely lead to broad antibody resistance and immune evasion of vaccinated sera, bringing additional uncertainty regarding the efficacy of existing vaccines.
The nanoparticle was shown to elicit equivalent or greater neutralizing antibodies against variant strains in mice and non-human primates with only a small reduction in neutralization titers against the ancestral strain, according to the study published in the journal Nature. Communications.
They also tested the vaccine against the Omicron and Lambda variants of the coronavirus. Both variants only slightly reduced the neutralizing potency of the vaccine-induced sera, suggesting that the induced sera could elicit largely protective antibody responses against the circulating variants.
The results provide proof of principle for the development of multivalent vaccines against potential pandemic and pre-emergent variants of SARS-CoV-2, the researchers said.