By Jeremy Manier
This may be the best expression I’ve seen yet of why swine flu still is a source of concern, even though it’s looking about as severe as normal influenza. From the Wall Street Journal’s coverage of a press conference today with Keiji Fukuda of the World Health Organization:
The reason why we’re paying so much attention to this virus is that the seasonal flu viruses have been around and circulating for many years. We understand their behavior and know most people have had previous infections and some immunity to them. When a new virus enters the human population and people do not have immunity to this virus, then the levels of serious illness and the levels of death can be higher than what we see with regular seasonal influenza.
…In the past, we’ve seen pandemics cause relatively fewer deaths, and some cause relatively huge amounts of death. One of them started out mild in the spring and over the course of several months became a severe illness. This is a situation in which things can evolve, and can do so quite differently. That’s why so much attention is being paid to what’s going on and why we’re jumping so hard on it. If it stays mild and people stay healthy, then that is great. But if it turns severe, then it’s something we have to know about, be prepared for and jump on.