TAIPEI (CNA) — A Taiwanese research team has developed a nasal spray vaccine to suppress lower respiratory tract infections caused by a virus that is a major cause of respiratory illness in young children and a contributing factor in infant death.
The team, headed by Chow Yen-hung (周彥宏), a research fellow at the Institute of Infectious Diseases and Vaccinology under Taiwan’s National Health Research Institutes (NHRI), called the patented vaccine a “major breakthrough” in the prevention of infections caused by the virus, known as “respiratory syncytial virus” (RSV).
Each year in Taiwan, about 1,000 newborns and toddlers are hospitalized due to RSV infection, and 90 percent of them are infants aged under 2 years, according to official statistics.
At a press event Monday, Chow said that what makes RSV infection dangerous to patients is that it develops rapidly.
“It takes only two to three days for the symptoms to turn worse from a fever to respiratory distress, and further develop into pneumonia or bronchitis,” Chow said.
Severe RSV infection occurs in 5 percent to 10 percent of infected children aged under 5, and the mortality rate is 1 percent, according to Chow.
Even worse, the lungs of patients who have recovered from the illness may sustain irreversible damage, leading to symptoms such as asthma, Chow said.
A vaccine is particularly important, he said, because there is currently no cure for RSV infection, except for using costly monoclonal antibody therapy.
Using mucous membrane vectors, Chow’s research team has developed a modified adenovirus-based nasal spray vaccine, which it proved can effectively reduce the volume of RSVs that are infecting lung cells, further mitigating inflammation in the lungs.
Adenoviruses are a group of viruses that typically cause respiratory illnesses, such as the common cold, conjunctivitis (an infection in the eye that is sometimes called pink eye), croup, bronchitis, or pneumonia.
In children, adenoviruses usually cause infections in the respiratory tract.
Chow said the vaccine has successfully helped reduce RSVs in lung cells in mice during the experiments that have been done.
During trials using pregnant mice as subjects, his team found that after a mother subject was injected with two doses of the vaccine, she passed on the antibody to her newborns.
Chow’s team has patented the vaccine and completed a technical transfer to a local company in 2017. The vaccine is scheduled to be tested in human trials by the end of the year, the NHRI said.
Expressing the hope the vaccine can be available for the use of young children aged under 15 and seniors over the age of 65 in three years, Chow estimated that the vaccine will likely remain effective for as long as 20 years with two doses, based on the results of past research.
By Chen Wei-ting and Elizabeth Hsu