UNITED KINGDOM – Emergex, an Oxfordshire-based company has announced that it will soon begin clinical trials of a second-generation vaccine against Covid-19, a simple skin patch that uses T-cells to kill infected cells and may provide longer-lasting immunity than current vaccines.
The T-cell vaccines prime T-cells to quickly remove infected cells from the body after infection, preventing viral replication and disease.
T-cells find and destroy infected cells, whereas antibodies produced by current Covid vaccines stick to the virus and prevent it from infecting cells.
Other vaccines, such as those developed by Pfizer/BioNTech and AstraZeneca/Oxford University, elicit a T-cell response, albeit to a lesser extent.
The Swiss drugs regulator has given Emergex permission to conduct initial human trials in Lausanne, involving 26 people who will receive a high and a low dose of its experimental Covid-19 vaccine beginning on January 3rd. The trial’s preliminary findings are expected in June.
“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,” said Robin Cohen, the company’s chief commercial officer.
Current Covid-19 vaccines primarily elicit an antibody response that diminishes over time, necessitating booster shots to maintain virus protection.
The Emergex vaccine works in a different way, by quickly killing infected cells. This means it could provide longer-lasting immunity – possibly for decades – as well as be more effective at combating virus mutations.
T-cell immune response more effective
According to a study published in Nature, some people experience “abortive infection,” in which the virus enters the body but is cleared by the immune system’s T-cells at an early stage.
According to the researchers, the discovery could pave the way for a new generation of vaccines that target the T-cell response, resulting in much longer lasting immunity.
T-cell vaccine could play a complementary role in a mix-and-match approach in which different vaccines are given for the first, second, and third doses.
mRNA vaccines like the Pfizer/BioNTech shot work so well because they elicit a strong neutralizing antibody response.
The Pfizer vaccine is more effective against Covid than the AstraZeneca/Oxford vaccine, which elicits a stronger T-cell response.
T-cell vaccine could be used to supplement other vaccines because they may be more resistant to virus mutations.
“Antibodies are extremely sensitive to mutations, whereas T-cells can see many different parts of the virus.” That could be a selling point for T-cell vaccines,” noted Cohen.
The vaccine will eventually be given as a skin patch the size of a thumbnail, bristling with micro-needles that release the shot in seconds.
It can be stored at room temperature for up to three months, unlike other vaccines that must be stored in the freezer.
The Emergex shot, however, will not be available until at least 2025, which is the typical timeframe for vaccine development.
Last year, Covid vaccines were developed in months due to a sped-up regulatory process, but the emergency has passed.
In a separate Swiss trial, Emergex is testing another T-cell vaccine against dengue fever on humans, with preliminary results expected in January.
The company also intends to use its T-cell vaccines to combat influenza, Zika, Ebola, and other infections.
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