Researchers in Chile said Friday they have developed the first vaccine against a virus that commonly causes lung and respiratory tract infections in children.

The team said that after clinical trials can be held it hopes to market the vaccine against so-called respiratory syncytial virus (RSV) in four or five years.

RSV kills or forces the hospitalization of thousands of babies around the world each year.

According to the Mayo Clinic in the United States, the virus is so common that most children have been infected with it by age two.

In temperate climates like that of Chile, there are annual epidemics of the virus in winter.

After ten years of work the vaccine was developed by a team led by Dr. Alexis Kalergis at the Millennium Institute on Immunology and Immunotherapy.

"This virus is very harmful and costly for Chilean society and the vast majority of countries," said Kalergis.

He said the vaccine has been successful in tests with animals and now the team is ready for clinical trials on people.

"Assuming we have financing and the results are favorable, we could have a vaccine in four or five years," Kalergis said.