Genexine said Friday that the company expects its Covid-19 vaccine candidate, GX-19N, to prevent infection for a long time as it uses T cell immune response instead of antibodies.

GX-19N, a DNA vaccine, is a next-generation vaccine with nucleocapsid antibody added to the existing spike protein protecting from infections.

The company said that unlike existing influenza vaccines or hepatitis B vaccines, Covid-19 vaccines should have the T cell response, rather than the antibody response, as it could maintain stronger and longer efficacy on variants and breakthrough infection.

“As we are moving forward to live with the Covid-19 virus, the need for a safe vaccine that can respond to mutations with a long-lasting effect has been increasing instead of the vaccines that only raise neutralizing antibodies,” a Genexine official said. “GX-19N meets all these needs as a long-lasting Covid-19 vaccine.”

Genexine cited some recent studies as examples to support its claims.

For example, it said, a study conducted by a research team of University College London and was published in Nature showed that the Covid-19 was abortive thanks to T cells removing the virus at the early stage of infection.

Antibodies sometimes find it difficult to remove mutated viruses, but T cells attack the part where there is a little mutation. According to the study, T cells also quickly find and eliminate virus-infected cells, preventing them from further replicating or causing diseases.

Another study conducted by Professor Shin Eui-cheol at the Korea Advanced Institute of Science and Technology (KAIST) followed up with recovered Covid-19 patients for 10 months at the beginning of the pandemic and found that T-cell immune response maintained well regardless of the severity of symptoms.

Genexine pointed out that a new finding also supports the significance of the nucleocapsid protein in the Covid-19 vaccine that the company’s GX-19N aims for.

In a recent paper published in the Science by UC Berkeley on Nov. 4, researchers explained that the infectivity of Covid-19 increased due to mutations in the nucleocapsid protein.

The vaccines available in the market target only the spike protein, but GX-19N forms a wide range of T-cell immunity that aims at both the spike and nucleocapsid proteins, Genexine said.

“GX-19N with T-cell immunity could prevent Covid-19 patients from developing into severe conditions and leave longer neutralizing antibodies to protect the receiver,” a Genexine official said. “In clinical trials, we also have found no systemic side effects, such as thrombosis and myocarditis, and other mild adverse reactions.”