Filenews 18 January 2022
A new vaccine that is still in a Phase I clinical study promises activation of T-cells, immune memory cells, in the battle against the coronavirus.
The candidate vaccine, CoVac-1, was developed at the University of Tubbingen in Germany with funding from the Baden-Württemberg Ministry of Research, and includes six coronavirus peptides that have been found to be recognized by immune T-cells in patients who have passed the disease.
According to the results from the first clinical trials, as published in the scientific journal Nature, the vaccine candidate induces T-cell immunity for at least three months, while displaying a favourable safety profile.
In the phase I clinical trial, only one subcutaneous injection of CoVac-1 was given to 36 healthy adults in Germany aged 18 to 80 years. By the 56th day after the vaccination was carried out, no serious or life-threatening side effects occurred.
Side effects
All participants developed a granuloma [inflammation] at the injection site, which was to be expected. The granuloma remained at the site and after the 56th day. Also, about a third of the participants reported transient fatigue. Other side effects included severe local erythema in 19% of the participants, accompanied by severe edema [swelling] in 6% of them, but these subsided within two days. Also, 22% of participants reported swollen lymph nodes in the groin. In two people, chickenpox virus – shingles and herpes simplex virus were activated again. None of the volunteers contracted the virus up until the 56th day, the end of their follow-up period.
Effectiveness
Of the participants in the clinical trial, no one contracted coronavirus, during the screening period that lasted up to 56 days.
The vaccine candidate triggered the response of a series of T-cells, including interferon-gamma T-cells that lasted 3 months and exceeded those produced either by the infection itself in patients who passed through the disease, or had been caused by vaccination with the approved vaccines. In laboratory tests, it was found that mutated peptides from alarming variants of the coronavirus, such as Delta, did not affect the response of T-cells.
"CoVac-1 may well serve as a complementary vaccine to induce T-cell immunity, particularly in elderly and immunocompromized individuals with reduced ability to generate adequate immune responses after being vaccinated against the coronavirus with the currently approved vaccines," the study authors noted.
Researchers are now proceeding with a clinical trial to evaluate the same vaccine in patients with B-cell deficiency.
