The H1N1 flu virus "poses a serious health threat" to the United States, according to the Obama Administration’s advisory group on Science and Technology.

More needs to be done to speed up the "preparation of flu vaccine for distribution to high-risk individuals," otherwise the vaccine campaign  will have potentially missed the peak of the epidemic, says a Fox News report

Currently, distribution of the human vaccine is scheduled to begin in mid October.

"Based on the history of influenza pandemics over the past hundred years, President’s Council of Advisors on Science and Technology places the current outbreak somewhere between the two extremes that have informed public opinion about influenza," states the report. "On the one hand, the 2009-H1N1 virus does not thus far seem to show the virulence associated with the devastating pandemic of 1918/1919. On the other hand, the 2009-H1N1 virus is a serious threat to our nation and the world."

According to the Associated Press, “The global spread of swine flu will endanger more lives as it speeds up in the coming months and governments must boost preparations for a swift response to a coming "explosion" of cases, the World Health Organization said Friday.

Many countries could see H1N1 flu cases double every three to four days for several months until peak transmission is reached, once cold weather returns to the northern hemisphere, said WHO's Western Pacific director, Shin Young-soo.

"At a certain point, there will seem to be an explosion in case numbers," Shin told a symposium of health officials and experts in Beijing. "It is certain there will be more cases and more deaths."

The WHO says the H1N1 flu virus has killed almost 1,800 people worldwide, and has been declared a pandemic. International attention has focused on how the pandemic is progressing in southern hemisphere countries such as Australia where winter — and the flu season — has started.

But it is in developing countries that the accelerated spread of swine flu poses the greatest threat as it places underequipped and underfunded health systems under severe strain, Shin said. WHO earlier estimated that as many as 2 billion people could become infected over the next two years — nearly one-third of the world's population.

Others said Shin's cautionary comments were needed but that they were optimistic the spread would not be that serious. Ann Moen, an influenza expert with the U.S. Centers for Disease Control and Prevention, said that if current trends continue it is possible that the H1N1 flu pandemic will not be worse than a severe flu season.

Health officials and drug makers are considering how to speed up production of a vaccine before the northern hemisphere enters its flu season in coming months. Estimates for when a vaccine will be available range from September to December.

WHO has stressed that most cases of H1N1 flu are mild and require no treatment, but the fear is that a rash of new infections could overwhelm hospitals and health authorities, especially in poorer countries.

"We only have a short time period to reach the state of preparedness deemed necessary," Shin said. "Communities must be aware before a pandemic strikes as to what they can do to reduce the spread of the virus, and how to obtain early treatment of severe cases."

The last pandemic — the Hong Kong flu of 1968 — killed about 1 million people. Ordinary flu kills about 250,000 to 500,000 people each year.

H1N1 flu is also continuing to spread during summer in the northern hemisphere. Normally, flu viruses disappear with warm weather, but the current flu is proving to be resilient.

Sources: Fox News, Associated Press