State health officials are extending an immunization waiver of the two-dose chickenpox vaccine requirement for children entering Mississippi schools this fall.

The original waiver for the varicella vaccine was issued in November of last year.

The Mississippi State Department of Health said Wednesday that children entering school during the 2008-2009 school year will be required to have at least one dose of vaccine or a history of chickenpox.

The waiver is due to delays in vaccine availability.