ATLANTA, (Reuters) - About half the U.S. population  should get vaccinated against H1N1 influenza but pregnant women  and healthcare workers should be at the front of the line, U.S.  health advisers agreed yesterday.

Up to 160 million doses of flu vaccine will be available  for the start of a vaccination campaign planned for  mid-October. The Advisory Panel on Immunization Practices  recommended that state and local health officials prepare to  vaccinate as many as 150 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 health care workers,” said Kathy  Neuzil, ACIP influenza work group chairwoman.

The group nearly unanimously accepted advice from the U.S.  Centers for Disease Control and Prevention. The Human Services  Department almost always follow the advice of the committee.

The recommendations said pregnant women, people who care  for babies and healthcare workers should be the first protected  against the virus — a total of around 41 million people — in  the event that not enough vaccine is available.
People at risk of serious complications from catching the  flu should follow — 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.

“They penetrate our society at service-level jobs, at  entry-level jobs, so there is going to be a lot of transmission  from these people,” panel member Dr. Carol Baker of the Baylor  College of Medicine in Texas told the meeting.

Pregnant women are at special risk from the new strain, and  vaccinating them protects their newborns, too, the CDC’s Dr.  Anthony Fiore told the committee.
A CDC report released earlier yesterday showed pregnant  women were four times as likely as other people to suffer  severe complications and even die from H1N1 infection.

Five companies are making H1N1 vaccine for the U.S. market  — AstraZeneca’s MedImmune unit, Australia’s CSL Ltd,  GlaxoSmithKline Plc, Novartis AG and Sanofi-Aventis SA. It is  not clear how many doses of vaccine will be available right  away but the United States would need 600 million doses to  immunize everyone.