Scientists around the world are scrambling to develop a vaccine to stop the spread of the new coronavirus, but the best candidate might be an experimental one stored in a Houston freezer.

The vaccine, developed by researchers at Baylor College of Medicine and University of Texas Medical Branch at Galveston researchers, effectively protected mice against SARS, or severe acute respiratory syndrome, the virus from the same family that spread in the early 2000s. The vaccine never progressed to human testing because manufacturing of it wasn’t completed until 2016, long after SARS had burned out.

“It generated zero interest from pharmaceutical companies,” said Peter Hotez, a Baylor vaccine researcher and infectious disease specialist. “Because the virus was no longer circulating, their response was essentially, ‘thanks, but no thanks.’ ”

Hotez thinks the vaccine-in-storage can provide cross-protection against the new coronavirus, now officially named COVID-19, whose spread through China and, increasingly, to other countries has the world on edge. The virus, first detected in Wuhan, China, has now infected more than 75,000 people and killed more than 2,200, more than the 774 deaths from SARS. Although the bulk of the cases and deaths have occurred in China, COVID-19 now has been confirmed in 28 countries, the U.S. among them.

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The 34 cases in the United States — 21 repatriated individuals and 13 travelers who fell ill after returning — include three in Texas, an American citizen who was part of a group evacuated from China on a State Department-chartered flight, and two citizens on the Diamond Princess cruise ship. All three were taken to Lackland Air Force Base in San Antonio.

The Baylor-UTMB vaccine looks promising for COVID-19 because the virus so resembles SARS — Hotez calls it SARS-2 — which circulated between November 2002 and July 2003, mostly in mainland China and Hong Kong but also in Toronto, whose economy was so badly wrought by the outbreak that it needed a boost from a benefit concert featuring the Rolling Stones, Justin Timberlake and others to help shake the effects.

COVID-19 shares 82 percent of its genes with SARS and infects people through the same cell receptor, one of the “spike-like” proteins that stud the surface of coronaviruses and gives the family their name. The viruses originally jump from animals to people.

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The two viruses, which have mostly resulted in deaths in the elderly and people with serious underlying conditions, both can cause a severe form of viral pneumonia characterized by fever, cough and breathing difficulties. The early thinking is that COVID-19 is less lethal than SARS but more contagious.

There is no licensed treatment or vaccine for either, just supportive care focused on the symptoms.

The hope that the Baylor-UTMB vaccine should provide at least some, if not full, protection has had Hotez working the telephone the last few weeks, pleading with pharmaceutical companies and federal scientific agencies to pony up the funding needed to move the vaccine into clinical testing. The vaccine is still a candidate for such testing because the team has tested its continuing usefulness every six months, when it removes a sample from the freezer.

“It may require some tweaking, but it’s stable,” said Dr. James LeDuc, director of the Galveston National Laboratory on the UTMB Galveston campus. “Every virus is different, features some adaptations.”

The laboratory, a high-security biocontainment facility for the study of exotic disease, recently received the live COVID-19, which it will use to test the vaccine in mice, to see whether the SARS vaccine protects against it too. The lab’s researchers created mice engineered to replicate the human disease.

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Funding for clinical trials remains the big hurdle. Even with the new coronavirus circulating, Hotez has found few nibbles from pharmaceutical companies beyond the request to keep them informed and the suggestion their interest would pick up if the new coronavirus becomes a seasonal infection, like the flu.

Instead, Hotez is pinning his hopes for clinical trial funding on two grant proposals — one to the British government; and another to the Coalition for Epidemic Preparedness Innovations, an Oslo-based coalition of charities (the Bill and Melinda Gates Foundation is a sponsor) and governments that “aims to derail epidemics by speeding up the development of vaccines.”

The Baylor-UTMB venture is just one of the many ongoing efforts to halt the coronavirus epidemic. About 300 scientists dialed in remotely to a World Health Organization meeting last week to fast-track tests, drugs and vaccines to help slow the outbreak. UT-Austin scientists published a paper in Science on their creation of the first 3D atomic-scale map of the spike protein — the part of the virus that attaches to and infects human cells — that should provide a road map for better vaccine development.

At least eight initiatives to develop new vaccines have been announced, most of which use new technology, such as a type sometimes called genetic immunization, that is considered highly promising but has not yet led to licensure. One Houston firm, Greffex, said it has used genetic engineering to create a COVID-19 vaccine it will now take to animal testing.

Hotez said he thinks the Baylor-UTMB vaccine has an advantage because it’s already been successfully tested in animals and because it’s based on classic vaccine technology, the same technology used, for instance, in approved vaccines for Hepatitis B and the human papillomavirus. He said the less-than-perfect match should provide protection in the same way flu vaccines provide protection even though they’re not perfect matches.

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In addition to repurposing the SARS vaccine, the Baylor-UTMB team is working to develop a new vaccine targeting COVID-19. But Hotez acknowledged that work will take longer than the SARS vaccine. He said he’s surprised Chinese officials haven’t reached out to him about testing the vaccine in China.

Baylor’s work is conducted through its Texas Children’s Hospital Center for Vaccine Development, whose mission involves fighting public health threats that affect people who live in poverty — such as neglected tropical diseases and coronaviruses. It has made vaccines for neglected tropical diseases Chagas disease, schistosomiasis and hookworm, and the coronavirus MERS, or Middle East respiratory syndrome, “the camel flu” that originated in Saudi Arabia in 2012 and later was confirmed in South Korea. Unlike SARS, MERS does not resemble COVID-19.

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But the question is, can any vaccine make it through clinical testing in time to make a difference in the fight against an emerging epidemic or pandemic?

LeDuc noted that there are no shortcuts to the testing required to prove vaccines are safe and effective in people, a process he acknowledges could take a year, during which time the disease may burn out.

Hotez said the only thing that might expedite testing is if the spread of the disease becomes dire, a sobering thought that some public health officials think is looking more and more likely as COVID-19 is diagnosed in more countries.

It is why Hotez laments the missed opportunities to develop and stockpile vaccines for SARS, MERS and even Zika, the mosquito-borne infection that emerged in 2014-2017 but then burned out.

“It’s like little kids’ soccer games where everyone just follows the ball,” said Hotez. “They all run to the ball when it’s one spot, then to the next spot where it goes and then the one after that. No one stays at the goal to play defense.”

todd.ackerman@chron.com