Device-Aided Covid-19 Vaccine Invokes Immune Response

Scanning electron microscope image shows SARS-CoV-2 viruses emerging from the surface of cells cultured in the lab. (NIAID, NIH)

24 Dec. 2020. Results from an early clinical trial show a Covid-19 vaccine using an electronic device to boost uptake in cells is safe and generates an immune-system response. Findings from the trial testing the vaccine code-named INO-4800 by biotechnology company Inovio Pharmaceuticals appear in yesterday’s issue of the journal EClinicalMedicine.

Inovio Pharmaceuticals, in Plymouth Meeting, Pennsylvania, is a developer of vaccines and therapies for infectious diseases and cancer. In the company’s process, DNA plasmids — round, double strands of DNA — are ingested into cells, where they’re exposed to a series of mild electrical pulses called electroporation. These electrical pulses from a Cellectra device, also developed by Inovio, increase the uptake of DNA into the cells, to produce a stronger immune response.

The clinical trial is an early-stage test of INO-4800, the company’s vaccine protecting against the SARS-CoV-2 virus responsible for Covid-19 infections. As reported by Science & Enterprise in May 2020, preclinical studies with lab animals show INO-4800 produces antibodies from B-cells in the immune system that neutralize SARS-CoV-2 viruses, as well as invoke T-cells protecting against the invaders. In guinea pigs, the researchers simulated clinical delivery of the vaccine and found the vaccine produces antibody concentrations that block the coronavirus spike protein from interacting with the receptor proteins in cells.

The trial is enrolling 120 healthy volunteers at three sites in the U.S. Participants are randomly assigned to receive one of three dose levels of INO-4800, injected under the skin with electrical impulses from a Cellectra device, in two installments, four weeks apart. The study team is looking primarily for safety issues, such as adverse side effects from the vaccine, but also neutralizing antibodies and enzymes indicating T-cell responses in blood tests. No participants receive a placebo.

The paper reports on data from the first 40 participants in the trial. Of these participants, 20 received a 1-milligram dose of INO-4800 and 20 received 2 milligrams, a 1-milligram dose in each arm. Results show after eight weeks, only six participants experienced adverse effects, with those events rated as mild.

Of the 40 participants, 38 were able to provide follow-up blood tests for immune response testing. Some 78 percent of 1-millimeter dose recipients, and 84 percent of 2-millimeter recipients produced neutralizing antibodies in sufficient concentrations to protect against infections. Moreover, after eight weeks, three-quarters (74%) of the 1-millimeter dose recipients and all (100%) of 2-millimeter recipients produced immune-system enzymes indicating T-cell responses to the vaccine.

Inovio notes in a company statement that INO-4800 “is stable at room temperature for more than a year, at 37^o C (98.6^o F) for more than a month, has a five-year projected shelf life at normal refrigeration temperature [i.e., at 2-8^o C / 35.6 – 46.4^o F] and does not need to be frozen during transport or storage.” The company says a mid- and late-stage trial of the vaccine, enrolling more than 6,500 participants, began earlier in December.

Coalition for Epidemic Preparedness Innovations, or CEPI, funded the early-stage clinical trial of INO-4800, while the U.S. Department of Defense is funding the mid- and late-stage trial. Inovio is not taking part in the U.S. government’s vaccine project known as Operation Warp Speed.

More from Science & Enterprise:

• Univ. Lab, Biotech Partner on Covid-19 Vaccine Implant
• University Halts Covid-19 Vaccine Trials
• Daily Covid-19 Nasal Spray Vaccine in Works
• Infographic – Vaccines Boost Biotech Shares
• Covid-19 Vaccine Shown Effective, Temperature-Stable

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