ABC's Clark Bentson reports from Rome:

While the debate continues in the United States on who should be prioritized for the H1N1 innoculations, the arrival of the first batches of the new vaccine sometime in September may not be in time to further exacerbate the global health pandemic.

The largest annual gathering of humans in the world is about to begin. Three million people more than 160 countries in the world are preparing for the Hajj and Umrah pilgrimages, a requirement for all Muslims who are physically able to visit their holy shrines in Mecca, Saudi Arabia at least once in their life time.

During their participation at the Hajj, it is widely feared that the large crowds of pilgrims could potentially expose each other to the virus.

The potential for the spread of the H1N1 virus is serious concern not only for Saudi officials who must deal with it locally, but for every Health Ministry of every country from which pilgrims come from. After completing their religious rites, the participants board crowded flight homes; possibly spreading the disease even more rapidly to every corner of the planet -- including to the United States. It is expected that up to 10,000 Americans will be part of this year’s pilgrimage.

Complicating matters, Saudi officials have reported their first deaths from the H1N1 flu this past week, and Indonesian officials have confirmed a death from a woman who recently returned from Mecca. Saudi Arabia has already diagnosed more than 230 cases of the H1N1 virus this year and is bracing for more. The country has enacted a national plan to combat a pandemic, and the plan "states clearly the steps to be followed to trace any suspect or disease contractor," according to a Saudi Health Ministry press release.

The two key periods of concern are during Ramadan when many people make their Umrah pilgrimage. The Umrah rites can be made at any time of the year, but are commonly done during Ramadan which this year is in August. The Hajj, which is when the vast majority of pilgrims travel to fulfill their obligations, is in November this year.

An emergency task force has been set up to try and identify and quarantine any pilgrims suspected of being infected. The Saudi Health Minister announced that they have requested 4 million doses of the H1N1 vaccine and that they have increased their supply of the Tamiflu vaccine to double the amount recommended by the World Health organization. Thermal scanners will be installed at airports to identify which passengers may already have fevers. Medical centers with additional staff will be erected in both Medina and Mecca.

Iran is already considering severely restricting its citizens from travelling to Mecca during Ramadan. An emergency session of Arab Health Ministers in late July made 15 recommendations to combat the spread of the flu. The most important of these recommendations is that all pilgrims receive their seasonal flu vaccine before departing for Saudi Arabia. Pilgrims are already required by the Saudi Hajj ministry to be vaccinated for meningitis, and have other vaccinations up to date before they are issued a Hajj visa.

Other recommendations included banning children under 12, adults over 65, and people with chronic diseases. Pregnant women are also advised not to attend. But these recommendations have yet to be approved by His Majesty, King Abdullah. The annual pilgrimage season is a big money maker for the Saudi kingdom in addition to it being a point of pride. The Saudi government has also rejected the calls from some in the Arab media to cancel this year’s Hajj.

For many this is a once in life trip that they have saved for. A great number of the pilgrims are poor and may never have another chance to travel. Officials believe this may lead many to dismiss or ignore possible indications that they have been exposed to the H1N1 virus, or are carriers themselves.

And many pilgrims remain unfazed. The Toronto Star quoted Qassim Hussein, A Canadian who recently left for Umrah, as saying, “Even if there was an outbreak of swine flu, I don't think I would be concerned," said Hussein. "Mecca is one of those places you go without fear of what might happen."

Noman Siddiqui, who is going for Hajj this November, shares those sentiments. "I'm not worried at all; it is just a blessing to be able to go."

This complacency is what Health Officials fear most.

"With Hajj being the largest human gathering (in the world), one can imagine how rapidly the H1N1 virus could spread," Qatar’s Public Health Department Director Dr Mohamed al-Thani told Gulf Times, a Bahrain based newspaper.

Jeddah's Hajj airport terminal will have 20 thermal sensors to check pilgrims and 20 percent more specialist medical staff than last year, said Mohamed Al-Harthi, health manager at Jeddah airport. The team of 550 people will include doctors, nurses, lab technicians and pharmacists.

But the medical response teams are under no illusion that their measures will stop infected people from entering the country.

"The thermal cameras are not 100 percent effective. We know that 30 or 40 percent of the patients could be incubating and will pass by the camera and show symptoms a few days later," Ziad Memish, assistant deputy minister for preventative medicine at the Saudi Ministry of Health told Reuters. He said the sensors would stop up to 70 percent of the infected cases that could enter the country.

Khaleel Bahador, a member of the Saudi National Committee for the Hajj and Umrah, said most of the workers employed to assist the huge numbers of people in the pilgrimage have gained enough experience over the years to deal with epidemic diseases.

“The swine flu is only a ring in a chain of pandemics which were on the spread lately including SARS, dengue fever, rift valley fever and others,” he told the Arab News newspaper, adding that the precautionary measures taken against the spread of the swine flu was so far the largest undertaken by the government.