An Imperial College London research released on Monday discovered that high numbers of T-cells from common cold coronaviruses can confer protection against COVID-19, which could inspire techniques for second-generation vaccinations.

While there is evidence of declining antibody levels six months after vaccination, T-cells are also thought to play an important role in giving protection against COVID-19.

The research, which began in September 2020, examined levels of cross-reactive T-cells generated by past common colds in 52 home contacts of positive COVID-19 individuals immediately after exposure to see if they developed illness.

It was discovered that the 26 persons who did not become sick had much larger amounts of those T-cells than those who did become infected. Imperial did not specify how long the T-cell protection would persist.

“We discovered that large amounts of pre-existing T cells, which the body produces when infected with other human coronaviruses like the common cold, can guard against COVID-19 infection,” stated research author Dr. Rhia Kundu.

The study’s authors, who published their findings in Nature Communications, believe that the intracellular proteins of the SARS-CoV-2 virus that are targeted by T-cells might provide an alternative target for vaccine developers.

Current COVID-19 vaccines target the spike protein, which mutates often, resulting in variations such as omicron, which reduce vaccination effectiveness against symptomatic illness.

“In contrast, the intracellular proteins targeted by the protective T-cells we uncovered change far less,” stated co-author Professor Ajit Lalvani.

“As a result, they are substantially conserved among SARS-CoV-2 variants, including omicron.” New vaccines containing these conserved internal proteins will thereby trigger widely protective T cell responses, potentially protecting against present and future SARS-CoV-2 variations.”