A T-cell based Covid vaccine may last longer than the current jabs, providing long-lasting immunity against future emerging variants and could be used as a model for other seasonal viral diseases like the flu, an Indian-American researcher has revealed.

The current Covid 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, Pennsylvania State University researchers in the US partnered with Evaxion Biotech on a study that was the first to demonstrate the effectiveness of an AI-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 per cent of the mice that were vaccinated with the T-cell-based vaccine survived, while only one of the control-group mice survived.

Additionally, all the vaccinated mice that survived cleared the infection within 14 days post-challenge, said the study published in the journal Frontiers in Immunology.

"To our knowledge, this study is the first to show in vivo 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," he added.

The research also paves the way for the potential rapid design of novel T-cell vaccines against emerging and seasonal viral diseases, like influenza.

According to Kirimanjeswara, 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.

"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 noted.

The virus would have to undergo too many mutations to be able to escape this T-cell-mediated immunity, so that is one advantage.

"The second advantage is that T-cell-mediated immunity is usually long lasting, so you don't need repeated booster doses," Kirimanjeswara explained. [IANS/NS]