In addition to Covid-19, it may also serve as a model for other seasonal viral diseases, according to Indian American researcher
An artificial intelligence-generated T-cell based vaccine may provide long-lasting immunity against future emerging variants of Covid-19, according to a study by Pennsylvania State University researchers led by Indian American professor, Girish Kirimanjeswara.
Such a vaccine may could also be used as a model for other seasonal viral diseases like the flu, according to Penn State press release.
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The current Covid-19 vaccines are designed to trigger an antibody response to the SARS-CoV-2 spike protein, which is vulnerable to mutations that could make the vaccine less effective over time.
Focusing on the T-cell instead, Penn State researchers partnered with Evaxion Biotech on a study that was the first to demonstrate the effectiveness of an artificial intelligence-generated vaccine in a live viral challenge model.
In their study, the researchers challenged mice with a lethal dose of SARS-CoV-2 and found that 87.5% of the mice that were vaccinated with the T-cell-based vaccine survived, while only 10% of the control-group mice survived.
Additionally, all the vaccinated mice that survived cleared the infection within 14 days post-challenge. The results were published on April 11 in Frontiers in Immunology.
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“To our knowledge, this study is the first to show in vivo [in a living organism] protection against severe Covid-19 by an AI-designed T-cell vaccine,” said Girish Kirimanjeswara, associate professor of veterinary and biomedical sciences, Penn State.
“Our vaccine was extremely effective at preventing severe Covid-19 in mice, and it can be easily scaled up to start testing it in humans, as well. This research also paves the way for the potential rapid design of novel T-cell vaccines against emerging and seasonal viral diseases, like influenza.”
Even as the mRNA vaccines that are already in use are very effective, a T-cell-based Covid-19 vaccine is needed because the spike protein of the SARS-CoV-2 virus is under heavy selection pressure, which can result in mutations that drive the emergence of new variants, according to Kirimanjeswara.
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“This means that vaccine manufacturers will have to keep creating new vaccines that target new variants, and people have to keep getting these new vaccines,” he said.
Instead of targeting the constantly mutating spike protein, the team at Evaxion Biotech designed a vaccine that included 17 epitopes from various proteins of SARS-CoV-2 that are recognized by the immune system. These epitopes elicit an immune response from a broad selection of T cells, ensuring a sustained coverage of future variants.
“The virus would have to undergo too many mutations to be able to escape this T-cell-mediated immunity, so that is one advantage,” said Kirimanjeswara. “The second advantage is that T-cell-mediated immunity is usually long-lasting, so you don’t need repeated booster doses.”
Read: AI-designed T-cell vaccine extremely effective at preventing severe COVID-19 in mice (April 13, 2023)
If T cells are so great at remembering foreign agents, why were the first-generation Covid-19 vaccines designed to elicit responses from antibodies?
“It’s harder and takes longer to produce a T-cell-based vaccine than an antibody-based one,” said Kirimanjeswara.
“Given the urgency with which we needed a vaccine to address the Covid-19 pandemic, it makes sense that vaccine manufacturers created an antibody-based vaccine,” he said. “Now that the urgency has passed, a second-generation T-cell-based vaccine could be more effective and last longer.”