Western University researchers say a new approach to developing a COVID-19 vaccine shows a possibility for producing a longer-lasting immunity against different variants.
The study of the efficacy of a vaccine strategy was by Chil-Yong Kang, a professor in the university's microbiology and immunology departments, along with a team at the Schulich School of Medicine and Dentistry. Although the work is still in the very early stages, new findings appear promising in inducing a "robust immune response".
The newly developed vaccine uses a modified version of a harmless virus, as a vessel to deliver instructions to the body's cells. Unlike an mRNA-based vaccine used by Pfizer and Moderna, or an adenovirus vector used by AstraZeneca and Johnson & Johnson, Kang's method uses a recombinant vesicular stomatitis virus (rVSV) as the vector.
Researchers say when a spike protein found on the surface of the coronavirus was inserted, it triggered an immune response in the body. Kang's approach appears to be unique because he has modified the rVSV to have a mixed envelope, surrounding the virus in two types of spike proteins. By creating the mixed envelope, Kang said the body won't develop immunity to the vector virus itself, allowing a booster shot of the same dose to 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 said in a statement. "That's one advantage our approach has."
Kang also said the vaccine was modified to produce higher quantities of spike proteins. When tested on mice, the vaccine produced higher antibody responses and "significantly" reduced lung damage.
Kang added that it's important for world researchers to continue developing new, more efficient, and stronger vaccines to help stamp out the pandemic, especially as new variants emerge.
"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," Kang said. "This is critical for future vaccines for COVID-19 in order to have worldwide herd immunity and to eliminate this global pandemic."
In other research endeavours, Kang has also seen success in developing an HIV vaccine.