Independence Day comes around this weekend, and Napa will be flying its colors quite a bit more brightly this year, with a beefed-up Fourth of July parade and celebration on Saturday.

This month, the World Health Organization finally declared that the H1N1 virus has become pandemic. It reported a big jump in cases and fatalities since June 19. How many people this virus will sicken and kill depends, ultimately, on three things: the virus itself; the impact of what are known as non-pharmaceutical interventions; and the availability and effectiveness of a vaccine.