A University of Texas Medical Branch researcher is part of an international team responsible for developing an effective and safe vaccine that protects against the deadly Middle East respiratory syndrome or MERS.
The findings of Dr. Chien-Te “Kent” Tseng, senior author of the vaccine study, were published recently in The Journal of Infectious Diseases. Tseng, who has been at the medical branch for more than 25 years, is a professor of microbiology and immunology in the Center for Biodefense and Emerging Infectious Diseases.
In the United States, MERS is best known as a deadly respiratory virus that can be contracted in hospitals through human-to-human contact. It is fatal more than 30 percent of the time, health officials said.
“We found that most vaccines developed by universities or private industry to protect against MERS are effective in preventing disease but enhance lung pathology,” Tseng said.
MERS is a cousin to Severe Acute respiratory syndrome or SARS, which in 2003 became the first global pandemic of the 21st century caused by an emerging virus. Both syndromes are caused by coronaviruses associated with the common cold and are rare but highly contagious. They can be spread through particles in the air by inhaling and exhaling.
“MERS is not as contagious as SARS, but the mortality rate of SARS is 10 percent; for MERS it’s 35 percent,” Tseng said.
The primary target of MERS is the lung, and infection can be fatal once the lung is affected and the virus spreads to other organ tissue, he said.
Unknown to most of the general public is that MERS transmission to humans traces back to camels, especially in the Middle East. Tseng’s international team included researchers from a university and a medical research center in Saudi Arabia as well as doctors from Canada.
“Ranching camels is a big industry in Saudi Arabia,” Tseng said.
Lots of studies have been done to control the infection in camels that exhibit only mild symptoms — usually just a runny nose. But in humans, it’s a different story with the possibility of severe lung damage or death resulting from infection.
Saudi researchers are being trained on the ground, and all the primary investigation took place at the medical branch in Galveston through the Center for Biodefense and Emerging Infectious Diseases, Tseng said.
“In Saudi, when the virus emerged and people were struggling trying to understand the pathogenesis of the disease, they had very little information about the human side,” Tseng said. “We developed mice with receptors for the virus to mimic human infection — we were the first group to do that — and were invited to attend a meeting organized by the World Health Organization. From there, we established this collaboration.”
To move forward and develop human trials, Tseng and his team are trying to secure additional funding from the Saudi government, he said. Once the vaccine is fully developed, it could be used to protect health care workers who come into contact with the virus and are at risk of spreading it, and to protect camel ranchers in the Middle East.
MERS research often has posed serious safety concerns associated with the family of viruses MERS and SARS belong to, Tseng said. His study set out to use a different vaccine platform that was safer yet still effective, introducing two different versions of a potential vaccine to mice, one that protected the mice against clinical signs of disease and death, and the other that was unable to stop the virus from causing lung damage.
“I’m not saying this is the only effective vaccine, but I want you to know that it will be a safer vaccine,” Tseng said.
“I feel humbled to have been part of this project.”