The inevitable has become official. Today, the World Health Organization chief Margaret Chan announced that she had raised the pandemic alert scale to 6, the highest level, to indicate that a pandemic caused by the A (H1N1) swine flu virus is now underway. "The scientific criteria have been met," Chan told journalists gathered at WHO's main meeting hall in Geneva, Switzerland, just after 6 p.m. local time. "The world is now at the start of the 2009 influenza pandemic."
Agency officials all but acknowledged at a press briefing on Tuesday that the declaration was imminent, as they had in early May as well. WHO's official tally stood at 28,774 cases in 74 countries today, including 144 deaths.
Chan stressed that phase 6 indicates only geographical spread and does not denote an increase in severity. WHO characterizes the pandemic’s severity as "moderate," but Chan warned that the virus "can change the rules, without rhyme or reason, anytime.”
Yesterday, Chan spoke by teleconference with several WHO member countries about the spread of the A (H1N1) virus in their locales. Their input led her to seek advice from an Emergency Committee, as specified in International Health Regulations. “All member countries as well as the experts on the emergency committee reviewed the evidence and there was consensus, a unanimous decision, that we have indisputable evidence that we are at the beginning days of a global pandemic caused by a new H1N1 virus,” said Chan.
A major concern to WHO is that developing nations, already burdened with more disease and weaker health systems, might be disproportionately hit by the pandemic. Chan urged international solidarity to prevent this from happening. "This is a time when the world's countries …must come together," she said. "No country's people should be left behind without help." But she didn't provide specifics when asked later how supplies of a vaccine against the novel H1N1 virus, which will be very limited initially, can be distributed fairly.
A few companies have already started producing vaccine against swine flu, Chan said; many others are now wrapping up their production of seasonal influenza vaccine for next winter in the Northern Hemisphere and are expected to switch to the pandemic strain soon.
Asked what's likely to happen next, WHO's chief flu expert Keiji Fukuda said that as a large number of people around the world become infected, immunity to the virus will build up, which should eventually slow the virus's spread. At that point, A (H1N1) is likely to become a seasonal strain, he said, joining the three others—including a human A (H1N1) strain—that are currently circulating.
In the United States, the Centers for Disease Control and Prevention immediately held a press conference to discuss WHO’s decision. “The declaration of a pandemic does not suggest that there’s been any change in the behavior of the virus, only that it is spreading in more parts of the world,” said newly appointed CDC Director Thomas Frieden. “And really for all intents and purposes, the U.S. government has been in phase 6 of the pandemic for some time now. This however is important because it is does send the strong message that the virus is here, it’s in all likelihood here to stay, and it’s important that we continue our aggressive efforts to prepare and respond.”