On Apr. 2, 2020, an international collaboration of virologists at the University of Wisconsin-Madison and the vaccine companies FluGen and Bharat Biotech began the development and testing of a unique vaccine against COVID-19 called CoroFlu.

CoroFlu was to be developed on the backbone of FluGen’s flu vaccine candidate known as M2SR. Based on an invention by UW-Madison virologists and FluGen co-founders Yoshihiro Kawaoka and Gabriele Neumann, M2SR is a self-limiting version of the influenza virus that induces an immune response against the flu.

Refinement of the CoroFlu vaccine concept and testing in laboratory animal models at UW–Madison is expected to take three to six months. Bharat Biotech in Hyderabad, India will then begin production scale-up for safety and efficacy testing in humans. CoroFlu could be in human clinical trials by the fall of 2020.

Four Phase I and Phase II clinical trials involving hundreds of subjects have shown the M2SR flu vaccine to be safe and well tolerated. This safety profile, M2SR’s ability to induce a strong immune response, and the ability of influenza viruses to carry sequences of other viruses make M2SR an attractive option for rapidly developing CoroFlu as a safe and effective SARS-CoV-2 vaccine.

CoroFlu, like M2SR, will be delivered intranasally. This route of administration mimics the natural route of infection by coronavirus and influenza and activates several modes of the immune system. Intranasal delivery is more effective at inducing multiple types of immune responses than the intramuscular shots that deliver most flu vaccines.