As the World Health Organization raised its infectious disease alert level Wednesday and health officials confirmed the first death linked to swine flu inside U.S. borders, scientists studying the virus are coming to the consensus that this hybrid strain of influenza -- at least in its current form -- isn't shaping up to be as fatal as the strains that caused some previous pandemics. In fact, the current outbreak of the H1N1 virus, which emerged in San Diego and southern Mexico late last month, may not even do as much damage as the run-of-the-mill flu outbreaks that occur each winter without much fanfare. Let's not lose track of the fact that the normal seasonal influenza is a huge public health problem that kills tens of thousands of people in the U.S. alone and hundreds of thousands around the world," said Dr. Christopher Olsen, a molecular virologist who studies swine flu at the University of Wisconsin School of Veterinary Medicine in Madison. Flu viruses are known to be notoriously unpredictable, and this strain could mutate at any point -- becoming either more benign or dangerously severe. But mounting preliminary evidence from genetics labs, epidemiology models and simple mathematics suggests that the worst-case scenarios are likely to be avoided in the current outbreak. "This virus doesn't have anywhere near the capacity to kill like the 1918 virus," which claimed an estimated 50 million victims worldwide, said Richard Webby, a leading influenza virologist at St. Jude Children's Research Hospital in Memphis, Tenn.