In a study published in The Lancet, scientists have revealed that a virus responsible for wheezing and pneumonia claims the lives of as many as 200,000 children worldwide each year.
The study marks the first time that the number of childhood deaths globally resulting from respiratory syncytial virus (RSV) has been quantified.
About 3.4 million children were hospitalized after contracting RSV, scientists from the University of Edinburgh said. RSV is the single largest cause of lung infection in children.
"Acute Viral Bronchiolitis (RSV) is a respiratory virus which is not well known, however it is the most common reason for tiny babies to be admitted to hospital within the first year of life - across England and Wales RSV causes 20,000 babies to be admitted to hospital each year during the winter months," Professor Warren Lenney, spokesman for the British Lung Foundation, told the BBC.
The hope, researchers say, is that the research will contribute to the development of a vaccine to fight the infection.
According to the study, children under the age of two are most prone to RSV infections, which usually causes mild, cold-like symptoms but can, in babies who were premature or who have congenital heart disease, result in serious illness.
The team studied unpublished data from developing countries as well as published medical research on RSV infection as part of the report, which found that about 33.8 million children are infected each year with RSV.
Additionally, the report says, 99 percent of RSV-related deaths occur in developing countries.
"Our greatest hope of fighting this virus is to develop a vaccine, but before we can implement an immunization program, we need to understand exactly how big a problem RSV poses," Dr. Harish Nair, of the University of Edinburgh's department of population health studies, told the BBC. "This is the first time we have gathered information on such a global scale and is the best estimate we have for the number of children dying each year from this preventable illness."