Little will change, though, as health officials in the worst-hit countries (particularly the US) have been treating it as such for quite some time now. They warned, however, that the pandemic is currently only "moderate in severity." 

In practical terms, what does this mean?

But it will accelerate the production of a vaccine against the new virus. Several countries have signed contracts for the vaccine with manufacturers that call for its production if a pandemic is declared. Most of them have received so-called seed stock viruses from the CDC in the past two weeks, allowing them to begin the lengthy process of growing the virus in eggs and producing vaccines. But it will still take a minimum of four to six months for the vaccines to be available for use.

The announcement will have more impact on Third World countries, freeing up additional funds for treatment and prevention and helping to make stocks of antiviral drugs more readily available.

But they emphasize that the designation has much more to do with its globalness than its severity:

The WHO has hesitated to raise the alert level for fear that such an announcement would be misconstrued as an indication that the virus has become more pathogenic. WHO spokesman Gregory Hartl emphasized today that "Phase 6 doesn't mean anything concerning severity, it is concerning global spread. . . . Pandemic means global, but it doesn't have any connotation of severity or mildness."

In fact, he said, all evidence to date is overwhelming that the virus is mild in its effects.

But there is concerns (and this is one of the primary reasons behind the aggressive efforts to nip it in the bud and prevent its spread), this currently "mild" virus is only in Round 1 and could become more severe:

Experts fear, however, that as it passes through populations, it could mutate to become more lethal and return with increased force in the winter influenza season. That is what happened with the Spanish flu pandemic of 1918.

And of course, if its spread is successfully curbed, all the critics will talk about what a waste of money and energy it was for all the efforts because (say it with me) public health specialists are condemned for their failures and called chicken little for their successes. 

Meanwhile, Korea has (total now 55) and Hong Kong, which was hard hit by SARS a few years back, is closing all preschools and primary schools after a cluster of twelve students were infected at a single school. Japan and the US, from which many Koreans and others travel to Korea, are at 518 cases and 13,217 cases, respectively, as of the last WHO report (June 11). For Japan that's an increase in 33 cases since the previous report three days earlier.