"That's what a large part of the study is — allowing us to focus our energy on sites where the evolution of the virus occurs so we can defeat it."

One weakness in the data was the inability to classify it by geographic region, he said, which would have allowed researchers to better understand which rhinovirus variations cluster in what locations.

"We believe there would be variations by geographic region," Crandall said. "We certainly see that in other viral systems. We often find temporal clustering — meaning you have outbreaks with things like influenza, the 1988 outbreak and 1990 outbreak, each of them forms a very tight genetic cluster of variation."

Crandall said the research is the first step in developing a vaccine strategy that would take into account the amount of variation in the virus that causes that sniffly, achy, sore-throat feeling.

E-MAIL: carrie@desnews.com