CoroFlu is a one drop COVID-19 nasal vaccine built on a flu vaccine “backbone” that has been shown to be safe and well-tolerated in humans, in Phase I and Phase II clinical trials

Bharat Biotech is getting into development and testing of a vaccine against COVID-19 called CoroFlu as part of an international collaboration of virologists and vaccine makers.

CoroFlu is a one drop COVID-19 nasal vaccine built on a flu vaccine “backbone” that has been shown to be safe and well-tolerated in humans, in Phase I and Phase II clinical trials, the Hyderabad-headquartered vaccine maker said.

Announcing that ‘CoroFlu’ is under development, a statement from the company on Friday said the product is part of an international collaboration of virologists at the University of Wisconsin–Madison and vaccine companies FluGen along with Bharat Biotech.

CoroFlu will build 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. Kawaoka’s lab will insert gene sequences from SARS-CoV-2, the novel coronavirus that causes the disease COVID-19, into M2SR so that the new vaccine will also induce immunity against the coronavirus.

Head of Business Development at Bharat Biotech Raches Ella said “Bharat Biotech will manufacture the vaccine, conduct clinical trials and prepare to produce almost 300 million doses of vaccine for global distribution. Under the collaboration agreement, FluGen will transfer its existing manufacturing processes to Bharat Biotech to enable the company to scale up production and produce the vaccine for clinical trials.

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 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, the release said.

“We are going to modify M2SR by adding part of the coding region for the coronavirus spike protein that the virus uses to latch onto cells and begin infection,” said Gabriele Neumann, a senior virologist in Kawaoka’s lab and co-founder of FluGen. “CoroFlu will also express the influenza virus hemagglutinin protein, which is the major influenza virus antigen, so we should get immune responses to both coronavirus and influenza,” she said.

According to the statement, M2SR is a unique form of the flu virus. It lacks a gene called M2, which restricts the virus to undergoing only a single round of replication in cells.

“The single replication means the virus can enter the cell, but it can’t leave,” says FluGen co-founder, president and CEO Paul Radspinner. “So, in essence it tricks the body into thinking it’s infected with flu, which triggers a full immune response. But since it can’t replicate further, you don’t get sick,” he said.

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, the statement said.

M2SR was developed by FluGen and includes technology exclusively licensed through the Wisconsin Alumni Research Foundation (WARF), which manages patents for UW–Madison.