A second US company is poised to begin a small safety test of a vaccine against the new coronavirus.

Inovio Pharmaceuticals said Monday that it has Food and Drug Administration (FDA) permission for the study in 40 healthy volunteers in Philadelphia and Kansas City, Missouri, and plans to give its first dose of the experimental vaccine the same day.

The study, funded by the Bill and Melinda Gates Foundation, is a first step to see if the vaccine appears safe enough for larger tests needed to prove whether it will protect. Even if the research goes well, it is expected to take over a year before any vaccine could be widely available.

Last month, the first safety test in people of a different vaccine candidate began in Seattle. It was developed by the National Institutes of Health (NIH) and Moderna Inc.

Numerous other research groups are attempting to make vaccines against COVID-19 using a variety of different methods in hopes at least one will offer protection.

Inovio Pharmaceuticals is set to begin human testing for its coronavirus vaccine, the second to enter such trials in the US, the company announced Monday (file)

Most of Inovio's work focuses on HPV-associated cancers, but it also began developing a vaccine for MERS, a deadly coronavirus that emerged in 2012

Inovio's approach is what's called a DNA vaccine, made using a section of the virus's genetic code packaged inside a piece of synthetic DNA.

The company says it has already begun recruiting volunteers for its study in each of the two locations.

Testing will take place at the University of Pennsylvania's Perelman School of Medicine and the Center for Pharmaceutical Research in Kansas City.

Each volunteer will get two doses of the experimental vaccine, given four weeks apart.

'We anticipate rapid enrollment of this initial study,' said Dr Pablo Tebas, an infectious disease specialist and professor of Medicine at the Hospital of the University of Pennsylvania who is the principal investigator for that location.

'There has been tremendous interest in this vaccine among people who want to do what they can to help protect the greater public from this pandemic as soon as possible.'

Inovio anticipates that it will have enough data to do an initial assessment of the vaccine's safety as well as whether or not it's triggering an immune response in the participants by this summer.

As testing ramps up in the US, more and more coronavirus patients are being hospitalized. Numbers are only expected to increase until a vaccine like Inovio's is ready

It's not the first time that Inovio has worked on a coronavirus vaccine.

The company started developing a vaccine for Middle East Respiratory Syndrome (MERS), the most recent previous, new life-threatening coronavirus to emerge, in 2012.

When the company tested its MERS vaccine, 95 percent of trial participants' bodies generated high levels of virus-fighting antibodies.

And the vaccine ramped up the broader immune response - measured in search-and-destroy white blood cells, called T cells - for 90 percent of that phase I trial's participants.

So far, Inovio's new COVID-19 vaccine seems to work similarly to its MERS formula in lab studies - an encouraging indicator that it might work in human trials.

In preparation for the phase I study - and hopefully for a phase II trial - of its vaccine for COVID-19, Inovio says it has already manufactured thousands of doses of its vaccine, called INO-4800, in the past 10 weeks.

The company says it plans to have one million doses ready by the end of the year, which it will distribute pending the FDA's emergency approval.