The number of H1N1 flu cases in England might be levelling out, the Health Protection Agency said today as it reported an estimated 110,000 new infections in the week ending July 26th.
In the prior week, an estimated 100,000 new cases of swine flu were recorded in England - a big jump on previous infection figures.
"Overall, across the UK the indications are that the number of cases are no longer rising rapidly and may have plateaued," the agency said in a statement.
"There is no sign that the virus is changing. It is not becoming more severe or developing resistance to anti-virals and the small number of deaths has mainly been in older children and adults with underlying risk factors."
Most cases of swine flu in Britain have been mild. The agency said 27 people had now died in England after contracting the disease.
Meanwhile US health advisers agreed that about half the US population should get vaccinated against H1N1 influenza, with pregnant women and healthcare workers at the front of the line.
Up to 160 million doses of flu vaccine will be available for the start of a vaccination campaign planned for mid-October. The Advisory Committee on Immunisation Practices recommended that state and local health officials prepare to vaccinate as many as 160 million people.
Each person will likely need two flu vaccine doses and officials said it was not clear exactly how much vaccine would be available when.
"The main message is that it's half the population (who are the priority to be vaccinated). And it's the younger half of the population, as well as healthcare workers," Kathy Neuzil, the advisory committee's influenza work group chairwoman, said in an interview.
The recommendations said pregnant women, people who care for babies, and healthcare workers should be the first protected against the virus - a total of about 41 million people - in the event that not enough vaccine is available.
Children between the ages of six months and four years were also included in that group. The vaccine was not recommended for infants under six months.
People at risk of serious complications from catching the flu should follow, including those with asthma, diabetes and heart disease - and then healthy young adults aged 19 to 24, the panel said.
Members of the panel said young adults should be a priority because they are more likely to become infected and tend to work in places that would accelerate the flu's spread.
Pregnant women are at special risk from the new strain and vaccinating them protects their newborns, too, the committee was told. Surveys show that people over 65 are at lower risk of contracting H1N1.
Research released yesterday showed pregnant women with swine flu are four times more likely to be admitted to hospital than members of the general population.
The findings from the US suggest pregnancy places women at extra risk of serious complications from the virus.
Experts from America’s leading public health body said it reinforced the need to treat infected pregnant women with antiviral drugs “as soon as possible”.
Fears about the flu threat to pregnant women have been highlighted by the case of Sharon Pentleton, from Saltcoats, Ayrshire, who is now receiving specialist care in Sweden. She was flown to the Karolinska University Hospital in Stockholm after no beds were available at the only UK unit capable of treating her.
Ms Pentleton (26) is having her blood circulated through a machine and artificially oxygenated. Her condition is said to be “stable but critical”.
The new research was carried out by the US Centres for Disease Control and Prevention (CDC), the American equivalent of the UK Health Protection Agency and published in The Lancetmedical journal.
More than 700 people worldwide are known to have died after getting swine flu which the World Health Organisation says is spreading faster than any previous flu pandemic.
Agencies