A new mRNA vaccine for Covid-19 has been developed by Arcturus Therapeutic and Vinbiocare, two biotech companies based in the US and Vietnam respectively. The vaccine, called ARCT-154, contains not only the mRNA blueprint for the spike protein of SARS-CoV-2, but also enzymes from the virus that can multiply the mRNA in the human body. This means that the vaccine remains in the body for longer, allowing cells to produce more antigens against which the immune system can produce T-cells and antibodies. The vaccine requires smaller doses than those of Biontech/Pfizer and Moderna, making it significantly cheaper to produce. It can also be stored at room temperature in a powder form, which can be converted back into a vaccine by adding liquid.
However, the approach has the disadvantage that the RNA cannot be replaced by pseudouridine, which is believed to be a possible reason for the high efficacy of the mRNA vaccines from Biontech/Pfizer and Moderna. The scientists at Arcturus Therapeutic argue that high efficacy can still be achieved without this step. A clinical trial of ARCT-154 during the Delta and Omicron waves showed a high protective effect, with the vaccine preventing symptomatic illness in 55% of cases. The vaccine was well tolerated, with mostly mild or moderate side effects.
Vinbiocare has applied for emergency approval of the vaccine in Vietnam, where a large proportion of the population has already been vaccinated. Arcturus Therapeutic plans to apply for approval in the EU, US, and UK. The vaccine is expected to be primarily used as a booster.
