The global spread of swine flu, a pandemic, is highly likely, the World Health Organization said on Wednesday and raised its alert level to Phase 5, the next-to-highest level in the worldwide warning system.

Commuters wore protective masks at a subway station in Mexico City on Wednesday.

Pope Benedict XVI on Tuesday toured the wreckage left by the earthquake this month, offering comfort to survivors still living in tents here in the hardest-hit town, where 40 out of 300 residents died.

Federal officials said it would take until January, or late November at the earliest, to make enough vaccine to protect all Americans from a possible epidemic of swine flu.

And beyond the United States and a few other countries that also make vaccines, some experts said it could take years to produce enough swine flu vaccine to satisfy global demand.

The swine flu outbreak in New York may have spread beyond one school in Queens

By the time he sat down in the Oval Office to brief Michigan

A vaccine that protects babies against fatal bacterial infections was introduced in Rwanda last week, its first distribution in a third world country.

The pneumococcal conjugate vaccine has been sold under the Prevnar brand name in the United States since 2000, and Rwanda will get three million doses

Many people scour the Maine woods for lakes with big trout, but just a few seek places like this unnamed four-acre lake near the Machias River. Like thousands of other Maine lakes, it is scenic and remote, but it claims a rare distinction: it has no fish.

The Obama administration stepped up efforts to reverse a rule adopted late in the Bush administration that makes it easier for companies to deposit debris from mountaintop coal mining near streams. Interior Secretary Ken Salazar, left, said that the rule was legally flawed and that he had asked government lawyers to press a federal court to vacate it and send it back for reworking.

After eight years largely on the sidelines of the international policy debate on climate change, the United States is prepared to lead negotiations toward a new global warming treaty, Secretary of State Hillary Rodham Clinton said Monday.

Secretary of State Hillary Rodham Clinton addressed delegates at a climate and energy conference on Monday in Washington.

While confirmed cases of swine flu increased only slightly on Monday, the World Health Organization voted to raise its global pandemic flu alert level, but at the same time it recommended that borders not be closed nor travel bans imposed.

The W.H.O.