Annually in the U.S., yes, as the CDC source says. I believe the free full text is available, but since you're "skeptical" I'll quote: "During 1990-1994, varicella was the underlying cause of death in an average of 43 children aged less than 15 years each year (CDC, unpublished data, 1998). During 1988-1995, up to 10,000 children were hospitalized each year for varicella or its complications (CDC, unpublished data, 1998). Ninety percent of the children who died did not have high-risk conditions for severe varicella." If someone ends up on a ventilator as a result of varicella pneumonia and then winds up succumbing to a staphylococcal superinfection, then it is reasonable to ascribe that death to varicella, and to call it vaccine-preventable, as the CDC does. '''''' Talk