Although the H1N1 virus has not proven as deadly as the annual bouts of seasonal flu, the World Health Organization (WHO) raised the pandemic threat level today from 5 to 6, the highest designation, signaling that there has been substantial "community transmission" on multiple continents. 

At least 28,774 cases of the virus have been reported in 74 countries, and 144 people have died, the WHO reports on its Web site. For comparison, the seasonal flu kills an average of 36,000 people in the U.S. every year, according to the U.S. Centers for Disease Control (CDC).

"The world is now at the start of the 2009 influenza pandemic," WHO Director-General Margaret Chan said in a press conference today. "Further spread is considered inevitable." Now that the virus has been acknowledged as a global pandemic, it's more like "a marathon—you're not talking about a sprint," said another WHO spokesperson, who expects it to spread for the next couple years until people begin to develop immunity to the strain.

A $20 chip can cut the time it takes to distinguish swine flu—aka the H1N1 influenza A virus—from days to hours, the U.S. Centers for Disease Control and Prevention (CDC) said today.

The technology—InDevR, Inc.'s FluChip—includes normal 0.8- by 2-inch (2- by 5-centimeter) lab slides featuring a pencil-eraser sized patch of tiny dots containing pieces of influenza's genome. Researchers place a drop of a solution containing a sample of chemically amplified RNA (which the viruses use to make proteins) from the virus they're studying onto the slide. Once the dots react with the solution, the FluChip is placed in a 4-pound (1.8-kilogram) IntelliChip Reader where it's scanned and a digital image is produced that can help physicians identify an influenza virus down to its subtype. The process takes about seven hours.

Researchers have already demonstrated in the lab that the materials the body uses to make proteins can also successfully suppress several different types of viruses, including HIV and influenza A, by disrupting the formation of viral proteins. Less clear, however, was how to get these virus-busting molecules where they needed to be in the body in order to keep viruses from spreading. Now a team of Yale University researchers believe they have found an effective way of delivering these special, short-interfering RNA (siRNA) molecules to specific locations within the body's biological battlefield.

As the World Health Organization (WHO) today acknowledged the spreading swine influenza virus by moving the pandemic threat awareness level up one notch to 5, the U.S. Centers for Disease Control (CDC) worked to get drug companies the materials they need to create a vaccine. Meanwhile, the U.S. Department of Health and Human Services (HHS) said it is unlikely that any new swine flu vaccine would be included in the batches of seasonal influenza vaccines already in production for the typical August vaccine ship date.

CDC and others are working to create the virus reference strain by the end of May that drug companies need to make a vaccine, says Bruce Gellin, director of HHS's National Vaccine Program Office and the agency's deputy assistant secretary for health. Once these companies make the necessary adjustments to their facilities and processes (which usually takes two or more weeks), he adds, they begin developing a pilot vaccine that the National Institutes of Health (NIH) tests to determine the amount of antigen per dose and number of doses, as well as information on safety.

With swine flu infections now being reported in six different countries, and concern mounting for even more, researchers are looking for ways to keep the outbreak in check. Influenza's unpredictability has stymied efforts to create a universal vaccine that could be mass-produced in advance of a pandemic threat and used to treat a variety of different virus strains.

Instead, drug companies annually try to predict which strains are most likely to circulate and then make enough of a particular flu vaccine to address those strains. Unfortunately, the wrong type of influenza vaccination provides little protection: for example, vaccination with seasonal influenza vaccine containing human influenza A (H1N1) would not be expected to provide protection against swine influenza A (H1N1) viruses, according to the U.S. Centers for Disease Control. The H and N refer to viral proteins, hemagluttinin and neuraminidase, that help the virus infect cells and reproduce within a host. Even viruses that share the same major subtypes—in this case, the H1 and N1—can have subtler differences and a vaccine against one might not generate antibodies that are effective against the other.

With the number of confirmed U.S. swine flu cases double the 20 it was yesterday, the government says that it is closely monitoring the swine flu outbreak and is preparing for further spread.

"This is obviously the cause for concern and requires a heightened state of alert, but it's not a cause for alarm," President Obama said today at the National Academy of Sciences (NAS).

In the U.S., 40 cases have been confirmed by the U.S. Centers for Disease Control and Prevention (CDC) in five different states: New York, California, Texas, Ohio and Kansas. All individuals have recovered, including the one that was hospitalized, Richard Besser, acting director of the CDC, said in a press conference today. Twenty of the cases have stemmed from a New York City preparatory school. Although that's more than twice the number originally reported, the additional cases were a result of further testing rather than continued spread of the flu, Besser noted. The CDC is distributing kits to test for swine flu in affected states, and as testing ramps up, Besser said, "I expect we will see other cases across the country."

The Food and Drug Administration (FDA) has green-lighted a test that can quickly determine whether a person is infected with deadly avian flu.

The FDA yesterday approved the AVantage A/H5N1 Flu Test, made by Sunnyvale, Calif.-based Arbor Vita Corp. The nose or throat swab can detect the infection in less than 40 minutes, the agency said; previous diagnostic tests took up to four hours.

"This test is an important tool to help quickly identify emerging influenza A/H5N1 infections and reduce exposure to large populations," Daniel Schultz, director of the FDA's Center for Devices and Radiological Health, said in a statement. "The clearance of this test represents a major step toward protecting the public from the threat of pandemic flu."

We've known since January that most of the flu circulating this season is resistant to Tamiflu, an antiviral drug typically used against the infection. What remained a mystery was whether the resistant flu strain made people sicker than forms that respond to the treatment — and why the resistant strain surged this year, a worry for public health officials who stockpiled Tamiflu in the event of a flu pandemic stoked by avian influenza.

A study published today in the Journal of the American Medical Association indicates that Tamiflu-resistant flu does not make people any more or less sick. But researchers say they're still in dark as to why Tamiflu-resistant infections are on the rise. A whopping 98 percent of this year's circulating H1N1 flu strains are immune to Tamiflu, compared with only 12 percent during the 2007-2008 flu season.

Is sunshine more than just a home remedy for a cold? New research suggests it may be: In a study that will be published tomorrow, people with low levels of vitamin D — also known as the "sunshine vitamin" — were more likely to catch cold and flu than folks with adequate amounts. The effect of the vitamin was strongest in people with asthma and other lung diseases who are predisposed to respiratory infections.

People with the worst vitamin D deficiency were 36 percent more likely to suffer respiratory infections than those with sufficient levels, according to the research in this week's Archives of Internal Medicine. Among asthmatics, those who were vitamin D deficient were five times more likely to get sick than their counterparts with healthy levels. And the risk of respiratory infection was twice as high among vitamin D-deficient patients with chronic obstructive pulmonary disease (COPD) than in lung patients with normal levels of the vitamin.

Tamiflu, an antiviral used to treat the flu, doesn’t work against most of the virus circulating in the U.S. this season, federal officials say.

It's not a serious problem so far, because fewer than the usual number of people have caught the flu this year, U.S. Centers for Disease Control and Prevention (CDC) authorities say. But 99 percent of cases this year are resistant to the drug, compared to 11 percent last year, The New York Times reports.

The resistance seems to stem from a spontaneous mutation in the virus, not the result of overuse of the drug, according to the Times. They've advised patients to use a Tamiflu rival, Relenza, or an older med called rimantadine, according to Bloomberg News.