Potential SARS vaccine eyed for coronavirus use

Thousands of doses of a potential vaccine for severe acute respiratory syndrome have been sitting in a freezer in Houston, Texas, shelved since 2016 after most of the world lost interest in the disease.

Now, four years later, they have been given new life because scientists hope they will also work for COVID-19.

Depending on the amount given to patients, anywhere from 23,000 to 230,000 doses are at a storage facility called Cryogene in Houston.

“We just could not get any money. Not from the government and not from private industry,” said Maria Elena Bottazzi, a professor of pediatrics at Baylor College of Medicine and one of the vaccine’s developers.

Three organizations have agreed to shepherd the vaccine through clinical trials and to ensure it is safe and affordable. The protein-based vaccine is made using yeast, a similar method to the one employed in the manufacture of hepatitis B vaccines used around the world.

“There’s a lot of knowledge and a lot of safety with this method,” said Bottazzi, who is co-director of the Texas Children’s Hospital Center for Vaccine Development. She said researchers hope to receive clearance from the U.S. Food and Drug Administration to start clinical trials as soon as September.

The three partners in the project are Baylor College of Medicine, Texas Children’s Hospital Center for Vaccine Development, and PATH, a 43-year-old global nonprofit dedicated to improving public health.

Deborah Higgins, PATH’s senior director for vaccine development, said that because the SARS virus and the new coronavirus “have so many similarities, we realized that there was reasonable potential for the vaccine to address the current pandemic . ...

“Instead of having to start from ground zero in developing a vaccine, this candidate is virtually ready to go.”

The vaccine, known as RBD219N1, was developed by Bottazzi and colleague Peter Hotez, co-director of Texas Children’s Hospital Center for Vaccine Development. It works by targeting the key mechanism used by both SARS and the new coronavirus to infect cells.

Both viruses use their spike protein to dock onto the outside of human cells, specifically onto one part of the cell, a receptor called ACE-2. Once the protein has docked, the virus is then able to penetrate the cells.

The vaccine hinders this connection between the virus and human cell by blocking the portion of the spike protein that latches onto a receptor.

Bottazzi said the vaccine has been tested in animals. It also has been tested successfully on a pseudovirus, a lab-made virus that closely resembles SARS-CoV-2 but is incapable of causing disease.

Before hitting a funding wall in 2016, a consortium spent about five years and $6 million in grants from the National Institutes of Health to develop and test the vaccine. The consortium included Baylor College of Medicine, Texas Children’s Hospital Center, the New York Blood Center, Walter Reed Army Institute of Research and the University of Texas Medical Branch in Galveston.

Once developed, the vaccine was manufactured by the Army. Then, in 2016, when researchers were ready to proceed to clinical trials, interest in the SARS vaccine vanished. Pharmaceutical companies weren’t interested. Neither were the Army or other agencies.

Other researchers eager to study SARS encountered similar problems. Though the disease faded away in 2004, scientists worried that another coronavirus would surface.

Nevan J. Krogan, a molecular biologist at University of CaliforniaSan Francisco, said he applied for a grant to do SARS research but was unable to get funding.

“There should have been a ton of research into SARS, but the money dried up,” Krogan said. “It was short-sightedness, not just on the part of government agencies, but also scientists themselves.”

Now, after four years in limbo, the Baylor team has managed to find support for its shelved vaccine.

Bottazzi stressed that researchers hope to keep the cost of their vaccine to less than $1 or $2 a dose. “It is becoming increasingly apparent that this virus poses great risk to low- and middle-income countries of South and Central America, Africa and Asia,” she said. “Our goal is to ensure that our development efforts lead to COVID-19 vaccines with global access.”