Single-dose COVID-19 vaccine triggers antibody response in mice — ScienceDaily

Throughout the entire world, wellbeing treatment employees and large-danger groups are beginning to get COVID-19 vaccines, supplying hope for a return to normalcy amidst the pandemic. On the other hand, the vaccines authorized for unexpected emergency use in the U.S. involve two doses to be helpful, which can build troubles with logistics and compliance. Now, researchers reporting in ACS Central Science have designed a nanoparticle vaccine that elicits a virus-neutralizing antibody response in mice right after only a solitary dose.

The major goal for COVID-19 vaccines is the spike protein, which is necessary for SARS-CoV-2’s entry into cells. Both of the vaccines at this time authorized in the U.S. are mRNA vaccines that lead to human cells to temporarily generate the spike protein, triggering an immune response and antibody generation. Peter Kim and colleagues wished to try out a distinct solution: a vaccine consisting of multiple copies of the spike protein exhibited on ferritin nanoparticles. Ferritin is an iron storage protein discovered in several organisms that self-assembles into a larger sized nanoparticle. Other proteins, these kinds of as viral antigens, can be fused to ferritin so that each nanoparticle displays quite a few copies of the protein, which could lead to a more robust immune response than a solitary duplicate.

The researchers spliced spike protein and ferritin DNA collectively and then expressed the hybrid protein in cultured mammalian cells. The ferritin self-assembled into nanoparticles, each bearing eight copies of the spike protein trimer. The group purified the spike/ferritin particles and injected them into mice. Just after a solitary immunization, mice developed neutralizing antibody titers that have been at least two instances bigger than all those in convalescent plasma from COVID-19 patients, and significantly bigger than all those in mice immunized with the spike protein alone. A next immunization 21 days later on developed even bigger antibody ranges. Though these outcomes should be confirmed in human clinical trials, they propose that the spike/ferritin nanoparticles may possibly be a feasible method for solitary-dose vaccination versus COVID-19, the researchers say.

The authors acknowledge funding from the Stanford Maternal & Little one Well being Study Institute, the Damon Runyon Cancer Study Foundation, the Countrywide Institutes of Well being, the Chan Zuckerberg Biohub, the Virginia and D. K. Ludwig Fund for Cancer Study and the Frank Quattrone and Denise Foderaro Family members Study Fund.

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