British company tests skin patch vaccine with longer immunity

UK company Emergex will soon start clinical trials of a second-generation Covid-19 vaccine in the form of a paste that is applied to the skin and uses T cells to destroy infected cells.

Emergex was founded in Abingdon in 2016 to develop T-cell vaccines - the brainchild of Professor Thomas Rademacher, Emergex CEO and emeritus professor of molecular medicine at the University Medical London.

The vaccine will produce T cells to quickly remove infected cells from the body, thereby preventing the replication of viruses and disease. While the antibodies produced by the current Covid-19 vaccine bind to the virus and prevent them from infecting cells, the T cells seek out and destroy the infected cells. Other vaccines such as Pfizer/BioNTech and AstraZeneca also induce a T-cell response, but to a lesser extent.

The Swiss drug regulator has given the green light to Emergex to conduct initial human trials in Lausanne. 26 volunteers will be injected with different doses of high-low vaccine, starting from January 3, 2022. Initial test results are expected to be released in June.

The company's chief commercial officer, Robin Cohen, said: 'This is the first time the regulator has approved a Covid-19 vaccine to enter clinical trials for the sole purpose of inducing a T-cell response. In the absence of an antibody response, the T cells seek out infected cells and destroy them'.

Compared to the process of an asteroid hitting a planet, Mr. Cohen likened the virus to an asteroid. It crashed into the planet, and a virus code — the signature of that virus — quickly spread across the surface. These markers will be considered foreign by the T cells and will destroy them before new strains of the virus can be created.

Current Covid-19 vaccines primarily produce an antibody response and weaken over time, meaning that people need a booster shot to maintain protection from the SARS-CoV-2 virus.

The Emergex vaccine works the other way around, by killing infected cells quickly. This means it can provide longer-lasting immunity - possibly for decades - and may also be better at fighting viral variants.

In addition, this new-generation vaccine will be developed in the form of a skin patch, the size of a fingernail, containing micro-needles. This vaccine can be stored for 3 months at room temperature, without the need for freezer or refrigerator.

However, Emergex's vaccine will not be on the market until 2025, based on the usual timeframe for vaccine development. Last year, Covid-19 vaccines were developed over several months as the licensing process sped up for urgent use. However, this emergency period is now over.

Robin Cohen added that the idea of ​​a T-cell vaccine is not new. For example, Professor Sarah Gilbert at the University of Oxford has been developing the AZ/Oxford vaccine for seasonal flu for more than a decade.

Emergex is also testing another T-cell vaccine against dengue in humans in a separate clinical trial in Switzerland, with initial results expected in January 2022. According to the World Health Organization (WHO), half of the global population is at risk of dengue fever and there is currently no specific treatment or vaccine for this disease.

The British vaccine research company also expressed its desire to develop vaccines against seasonal flu, Zika, Ebola and other infectious diseases.