A second US company is poised to begin safety test of a vaccine against COVID-19.

Inovio Pharmaceuticals said on Monday that the US Food and Drug Administration (FDA) has accepted the company’s Investigational New Drug (IND) application for INO-4800, its DNA vaccine candidate designed to prevent COVID-19 infection, paving the way for Phase 1 clinical testing in healthy volunteers beginning this week, reported Xinhua news agency.

The Phase 1 study will enroll up to 40 healthy adult volunteers in Philadelphia and Kansas City, where screening of potential participants has already begun, said the company.

The first dosing is planned for Monday. Each participant will receive two doses of INO-4800 four weeks apart, and the initial immune responses and safety data from the study are expected by late summer.

Additional preclinical trials, including challenge studies, will continue in parallel with the Phase 1 clinical trial, according to the company.

The study 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.

The first safety test in people of a different vaccine candidate, developed by the US National Institutes of Health and Moderna Inc., began in Seattle last month.

Numerous research groups around the world are attempting to make vaccines against COVID-19 using different methods in hopes at least one will offer protection.