In Japan, the number of cases rose to more than 120 over the weekend. Most of the ill there are teenagers.
WHO's annual meeting begins in Geneva, where the focus is on whether to make a swine flu vaccine and whether to raise to the alert level to pandemic level 6.
Sixteen schools are closed in New York City due to swine flu concerns.
Mitchell Weiner, a New York City assistant principal, dies from swine flu, becoming the sixth person in the U.S. to die from H1N1 virus. Other U.S. deaths previously reported in Texas, Washington state and Arizona.
Chile confirms its first two cases.
Latest numbers: 8,480 people sick in 40 countries. 75 dead, mostly in Mexico.
Australian researcher Adrian Gibbs, a scientist on the team that helped develop Tamiflu, says the swine flu virus may be a man-made experiment that mistakenly leaked from a lab. Upon reviewing his report, the CDC says there is no evidence to support his claims. WHO later dismissed Gibb's suggestion.
Latest numbers from WHO: Nearly 6,500 cases in 33 countries, more than 60 deaths.
Costa Rica confirms its first swine flu death -- the first death outside North America.
Based on data from previous pandemics, WHO suggests that as many as 2 billion people could be infected if outbreak gets worse.
With the U.S. government working on a reference strain that drug manufacturers can use to make a potential vaccine, health officials consider the best way to administer doses. Government has not yet said for sure that it will proceed with investing in a swine flu-specific vaccine.
Health officials talk vaccines: WHO says new vaccines wouldn't hit the market for about five to six months; manufacturers say they're well-positioned to produce mass vaccine quantities in case outbreak gets worse.
Last day of daily Homeland Security swine flu briefings unless news warrants. Napolitano says DHS will keep its guard up in the event the virus intensifies in the fall.
Latest numbers from WHO: More than 1,500 illnesses and 30 deaths.
Scope of U.S. pork export bans, according to the USDA Foreign Agricultural Service: Seven countries have banned live animals, pork and pork products from all states. Another five have banned pork and pork products from all states. Other countries have banned products from several states -- including China, which has prohibited all live pigs and pork products from 38 U.S. states.
A chartered plane from Mexico arrives in China to pick up its quarantined citizens.
Latest U.S. numbers: 380 confirmed cases in 36 states; First American citizen with swine flu dies.
More than 150 experts meet in Geneva, Switzerland, to assess the virus.
The CDC says keeping U.S. schools closed is not necessary.