A new study says the H1N1 "swine flu" virus spreads faster than first thought.
And the flu has spread to more countries.
There are now cases confirmed in Thailand and Finland, as well as Cuba and China.
That comes even though both regimes imposed strict measures on travel to Mexico.
The new study estimates the swine flu strain kills between .4 and 1.4 percent of those who get it.
But scientists say this new strain seems to be much more contagious than normal seasonal flu.