UK firm to start trial of new skin patch vaccine targeting T-cell against Covid-19

A UK-based company is set to begin clinical trials of an easy-to-administer skin patch against Covid-19, the media reported.

While Covid vaccines target antibody responses -- getting stuck to the virus and stopping it from infecting cells -- Emergex's vaccine uses T-cells to find and kill infected cells thus preventing viral replication and disease, The Guardian reported.

The vaccine will be administered as a skin patch the size of a thumbnail bristling with micro-needles that releases the shot within seconds. It can last for up to three months at room temperature, unlike other jabs that need to be stored in the freezer or fridge.

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The skin patch consists of tiny gold particles coated in peptides (bits of proteins) designed to generate the T-cell response in the body, the report said.

Other Covid vaccines developed by Pfizer and AstraZeneca also produce a T-cell response, but to a lesser extent.

Further, the currently available Covid vaccines mainly elicit an antibody response that wanes over time, meaning people need booster shots.

But, Emergex's vaccine works differently. It kills infected cells quickly, which means it could offer longer lasting immunity -- possibly for decades -- and could also be better at fighting virus mutations, Robin Cohen, the firm's chief commercial officer, was quoted as saying.

The Swiss drugs regulator has granted approval for Emergex to conduct the initial human trial in Lausanne. The trial involves 26 people who will receive a high and a low-dose of its experimental Covid-19 vaccine, starting on January 3. Interim results from the trial are expected in June. However, the Emergex shot will not be available until 2025 at the earliest, the report said.

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"This is the first time a regulator has approved a Covid vaccine to go into clinical trials whose sole purpose is to generate a targeted T-cell response in the absence of an antibody response and those T-cells look for infected cells and kill them," Cohen said.

"The virus is the asteroid: it fires into the planet and a viral code, a signature for that virus, is rapidly displayed all over the surface. These signatures are read by T-cells as foreign, and the T-cells kill the cell before it can produce new live viruses," he explained.

According to Danny Altmann, a professor of immunology at Imperial College London, a T-cell vaccine may not "do the job on its own" but could complement the current vaccines as boosters as T-cell vaccines might be more impervious to virus mutations.

"Antibodies are very sensitive to mutations while T-cells can see many other parts of the virus. Maybe that's a selling point for T-cell vaccines," Altmann was quoted as saying.

Emergex is also testing another T-cell vaccine against dengue fever on humans in a separate Swiss trial, with initial results due in January. The firm also wants to deploy its T-cell vaccines against influenza, Zika, Ebola and other infections.

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