The World Health Organization's flu chief says the H1N1 flu virus is now the predominant flu strain worldwide, and in some countries, it accounts for up to 70% of the flu viruses being sampled.

While most people recover from the illness without medical treatment, officials are still seeing severe cases in people under 65.

The WHO reports that the virus appears to be fairly stable, and samples from around the world remain very similar to when the virus was first identified in April.

The H1N1 virus is still on the move in Billings, but fewer students are staying home from school this week.

School District Two officials tell us in an average year, the daily student absence rate is about 5% and right now, the rate is below that in many schools.

That includes Riverside Middle School, which was hit hard by the H1N1 flu last month. The absentee rate there on Wednesday was at 4%.

The number of sick students out of school is slightly higher at other Billings middle schools, where it's around 8% to 9%.