source: New York Times

BRUSSELS — Anxiety over a new flu strain may have eased over the summer, but millions of Europeans will soon receive a sharp reminder of its virulence as governments prepare for a large-scale vaccination effort aimed at keeping a second — and possibly deadlier — wave of infections at bay.

With another surge in cases of the H1N1 virus — initially known as “swine flu” — expected as soon as September, medical experts say the battle to tame the first pandemic flu in four decades is just getting under way in Europe.

European Union health officials stress that most human cases of the flu have been mild and that patients recovered without special treatment. In another sign of normalcy, a committee of E.U. health officials recommended last week that schools reopen as usual after the summer break.

But with limited amounts of vaccines expected to become available this year, health authorities are girding for many more cases over the autumn and winter flu season, when viruses spread more easily.

“If we get a lot more infections, then there will be a lot more complications in people’s medical conditions and that means a lot more deaths,” said Nigel Dimmock, an emeritus professor in the department of biological sciences at the University of Warwick in England, and a flu expert.

Through Sunday, the European Center for Disease Prevention and Control, an E.U. agency based in Sweden, had recorded 38,187 confirmed cases and 60 deaths in European countries, compared with a global total of 228,921 confirmed cases and 2,084 deaths worldwide.

Those statistics show that Europe has suffered a relatively small number of cases. According to the World Health Organization, countries in North and South America have reported the vast majority of infections and deaths. But this is exactly the time, experts believe, that Europeans should be girding for a more widespread outbreak.

The global pattern of the virus’s spread indicated that “the pandemic is just beginning” in Europe, said Nikki Shindo, a spokeswoman on influenza for the W.H.O.

Up to 30 percent of the British population could become infected during the coming flu season, according to a spokeswoman for Britain’s Department of Health, who spoke with customary anonymity. During an ordinary flu season, between 2 percent and 15 percent of the population is affected, she said.

Britain had 12,903 confirmed cases and 44 deaths recorded through Sunday — the most of any European country, according to the E.C.D.C. Late last week, 39 people with suspected swine flu were in critical care wards in England.

This month, tests confirmed the symptoms of the H1N1 virus, none serious, on 59 students and five staff members at a language center for foreign students in France, near Monaco. The school confirmed there had been cases of swine flu detected but declined to make any further comment.

Others language schools in France have been taking precautions. Accent Français in Montpellier, which has around 150 students 16 or older — from countries including Germany, Spain, Switzerland, Britain and the United States — has stockpiled masks and put up notices on hygiene and medical contact numbers.

Through Sunday, there had been 1,125 cases and one death, recorded in France, according to the E.C.D.C.

“The virus does not appear to be overly aggressive now,” said Odile Launay, director of the Cochin-Pasteur Vaccinology Center in Paris, “but it could become so.”

She said researchers and experts had been surprised at the continuing appearance of new cases during the summer, when flu viruses generally remained less visible.

According to the E.C.D.C., Spain has recorded 11 deaths, the second highest number in the E.U., but has recorded 1,538 cases, far fewer than in Britain; Germany has recorded 11,493 confirmed cases, according to the E.C.D.C., but no deaths. The Robert Koch Institute, a German body responsible for disease control and prevention, said recently that the number of cases had been steadily increasing, with more originating indigenously than from citizens returning from trips abroad.

The W.H.O. said that about one-third of the world’s population would probably be affected by the time the pandemic had settled into a pattern and could be considered a seasonal flu virus — within about two to three years.

Ordinarily the process of developing new influenza vaccines is lengthy, so regulatory authorities in Europe have applied fast-track procedures to make them available as quickly as possible.