Lasting immunity and protection from new single-shot COVID-19 vaccine

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In a new study from Mass Eye and Ear, researchers found that a novel, gene-based COVID-19 vaccine was highly effective at eliciting neutralizing antibody responses and cellular immunity from a single dose.

The vaccine provided nonhuman primates near-complete protection against a live SARS-CoV-2 viral challenge.

The AAVCOVID vaccine was shown to be producible with efficient, scalable, and industry-established manufacturing processes.

The team further demonstrated that the vaccine product is stable at room-temperature storage conditions for up to one month, facilitating potential future distribution of the vaccine.

The study authors hope these findings support a move towards clinical trials with a goal of global distribution in parts of the world that are currently underserved by vaccination.

In the study, two AAVCOVID vaccine candidates with different SARS-CoV2 virus spike-based antigens were analyzed in a battery of experiments to measure effectiveness, duration of response, potency and stability.

The candidates were derived from genetic data collected on the Wuhan strain of the SARS-CoV-2 virus.

One vaccine candidate, AC1, was found to be superior in its ability to produce sustained immune responses in mouse and nonhuman primate models.

Next, to gain a better sense of how the vaccine might work in people, the AC1 AAVCOVID candidate was studied in a nonhuman primate model.

The team found The AC1 vaccine led to antibody levels that peaked at week 11 and remained at peak for at least 11 months.

The antibodies were detected in lung tissues, which may suggest mitigating some of the pulmonary effects of COVID-19 infection. The vaccine also induced long-term functional memory T-cell responses.

No adverse effects were observed in either animal model.

Further testing established the feasibility of large-scale manufacturing of the vaccine is already available industry processes through Novartis Gene Therapies.

The researchers also tested cold-chain storage requirements, or the need to keep the vaccines at specific low temperatures to retain potency.

They analyzed the vaccine’s potencies when stored at -112⁰F (-80⁰C), 39⁰F (4⁰C) or 77⁰F (25⁰C) to approximate freezing, refrigerated and room temperatures, respectively.

The vaccine was shown to be stable after one month at room temperature, with stability at colder temperatures exceeding three months.

The team says the remarkable efficacy induced in the nonhuman primate model after a single injection of the AAVCOVID vaccine does represent an important step in the development of a COVID-19 vaccine.

The different variants of COVID-19, including the Delta variant, were also neutralized by serum from the AC1 candidate in vaccinated animals.

Researchers believe an AAVCOVID vaccine has the potential to provide a more accessible option for people across the globe, especially to those with limited access to medical care

If you care about COVID, please read studies about vitamin D and COVID-19: What you need to know and findings of the cause of long COVID-19 symptoms.

For more information about COVID and your health, please see recent studies about fatigue, cognitive impairment and mood disorders linked to post-COVID-19 syndrome and results showing what you need to know about COVID vaccines and imaging scans.

The study is published in Cell Host & Microbe. One author of the study is Luk H. Vandenberghe, Ph.D.

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