Bacteriophages are helping humanity fight the novel coronavirus SARS-CoV-2. We've already reported on attempts to neutralize the virus and prevent its entry into target cells using modified phage capsids. Also noteworthy is the success of scientists from the University of Waterloo (Canada), who have developed a bacteriophage-based DNA vaccine in the form of a nasal spray for the prevention and treatment of COVID-19*.

A genetically modified bacteriophage serves as a carrier that specifically delivers a DNA fragment to the desired cells, in this case, the nasal mucosa. When the DNA enters the nasal epithelial cells, it triggers the synthesis of protein virus-like particles—completely harmless to human health, but similar in their surface antigens to the SARS-CoV-2 virus that causes COVID-19. These virus-like particles trigger an immune response in humans and animals that should also target SARS-CoV-2.

In addition to promoting immunity against SARS-CoV-2, virus-like particles can directly interact with the receptors that SARS-CoV-2 binds to, thereby limiting the pathogen's ability to enter cells. Therefore, a nasal DNA vaccine could theoretically both prevent COVID-19 and reduce the severity of the disease if infection has already occurred. This means that this vaccine could serve as both a preventative and a therapeutic agent.

The DNA vaccine will be tested on animals this year.

It should be noted that the study described has not yet been published in scientific journals and, therefore, has not undergone independent peer review.

* University of Waterloo developing DNA-based COVID-19 vaccine / APRIL 16 2020