Western researchers finding early success with new COVID-19 vaccine

A new vaccine being developed at Western University that uses a harmless virus is showing early promise in producing a stronger and longer-lasting immunity to COVID-19.

While the research is still in its early stages, data suggests the new approach provokes a "robust immune response."

The strategy was developed by Dr. Chil-Yong Kang, a professor in the microbiology and immunology departments, and a team from the Schulich School of Medicine and Dentistry.

The data, published in PLOS Pathogens journal, is from studies in pre-clinical mouse models and found they developed power antibodies against SAR-CoV-2, the virus that causes COVID-19.

Rather than the mRNA (Pfizer and Moderna) or adenovirus vector (AstraZeneca) based vaccines, researchers used a recombinant vesicular stomatitis virus, or rVSV, as the vector.

The gene for the spike protein found on the surface of the coronavirus was inserted into the rVSV, and triggers an immune response when introduced into the body.

The main difference is that the rVSV vector has been modified to have a "mixed envelope" surface carrying more than one type of spike protein, so individuals don't develop an immune response to the delivery virus itself, meaning a booster dose of the same vaccine can be given.

“Using the same virus, we get good boosting effects because we are generating rVSV with mixed envelope spike proteins on the virus particle,” Kang explained in a statement. “That’s one advantage our approach has.”

It also triggers a stronger immune response by secreting higher quantities of spike proteins.

Tests on mice found much higher antibody responses and significantly reduced lung damage.

Although the research is in its early stages, given new and emerging variants and the push for vaccine equity, Kang said it's important to continue.

“We hope our second-generation vector-based COVID-19 vaccine will induce a long lasting and strongly protective immunity against all variants of SARS-CoV-2,” he said. “This is critical for future vaccines for COVID-19 in order to have world-wide herd immunity and to eliminate this global pandemic.”

Kang has already seen promising success in his work to develop a vaccine for the HIV virus.