WASHINGTON -- With potential COVID-19 vaccines in their crosshairs, Army researchers have multiple candidates marching on to the next phase of testing, with hopes of human testing soon, officials said Wednesday.One of those potential vaccines, Spike Ferritin Nanoparticle, or SpFN, has pushed forward in the fight, and according to Kayvon Modjarrad, director of emerging infectious diseases at Walter Reed Army Institute of Research, or WRAIR, his team could start human trials by winter.The possible timeline is a delay from the original summer goal, officials said, to ensure a safe product.SpFN is a nanoparticle vaccine that deploys spike proteins to block infectious diseases, he said. He added that wielding spike proteins is a consistent approach used with other vaccine candidates, and isn’t a unique technique.In preparation, clinical-grade SpFN production trials began manufacturing last month, Modjarrad told reporters at the Association of the U.S. Army Annual Meeting and Exposition. The candidate recently advanced from being tested on smaller animals to larger ones -- more specifically from mice to non-human primates.The “U.S. Army has doctors, nurses, scientists, and Soldiers working on the front lines to help mitigate the impacts of the COVID-19 pandemic across our nation,” said Lt. Gen. Scott Dingle, Army surgeon general.The Army medical team works day and night on more than just potential vaccines and therapeutics to battle COVID-19, Modjarrad said. To prevent future outbreaks, the biomedical researchers are also focused on future coronavirus strains.To do this, WRAIR has set in motion “recombinant genetically engineered spike proteins,” Modjarrad said. “That will anticipate future coronaviruses that we haven't even seen yet. This is accomplished by researching coronavirus spike proteins not limited to bat populations.”Taking on deadly diseases is nothing new for the WRAIR researchers. In the past, they have taken on other viral heavyweights like Zika, Ebola, and HIV.However, just because SpFN leveled up, it doesn’t mean other candidates have fallen by the wayside. It’s one of three leading candidates, officials said.In a joint effort with public and private agencies, Army scientists have researched roughly two dozen potential candidates on five different vaccine tracks, said Secretary of the Army Ryan D. McCarthy during a press conference in March.To date, COVID-19 has infected more than 38 million people and has killed over a million. In the United States alone, nearly 8 million have tested positive for the coronavirus and 217,000 have lost their lives.The virus “does not discriminate, it affects people from all echelons and walks of life,” Dingle said. “The military is not immune to the novel coronavirus. The Defense Department has reported more than 65,000 cases of COVID-19.”As the Army’s war on COVID-19 wages on, Dingle said the best way to mitigate the virus is through proper hygiene. For example, “washing hands with soap and water for at least 20 seconds or using alcohol-based hand sanitizer containing at least 60% alcohol.”Also, everyone should “avoid touching [their] eyes, nose, and mouth with unwashed hands and avoid close contact with those who are sick,” Dingle said. “Cleaning and disinfecting frequently touched objects and surfaces should also be done.”In addition, Dingle recommends everyone wear cloth face coverings in public, especially when social distancing measures are challenging.For the latest on COVID-19, U.S. Army Medical Command officials suggest individuals check here for the most up-to-date information.Related linksU.S. Army guidance: COVID-19Walter Reed Army Institute of ResearchArmy Worldwide NewsFollow Thomas Brading on Twitter