Children and young adults have been hit hardest by the new virus, and pregnant women are at four times higher risk of hospitalization from it, said Anne Schuchat, the director of the National Center for Immunization and Respiratory Diseases at the CDC.
"We've had a number of deaths among pregnant women, and it really saddens us to know about those," she said.
After the target groups would come healthy adults up to age 65. Only about 2 percent of lab-confirmed cases of the new virus have been in seniors, and blood testing has found about a third of those born before 1950 have a strong antibody response to the new virus, possibly from previous exposure to similar antigens.
Still, "it's very important that people in that age group get their seasonal flu shots," Dr. Schuchat said. "The H1N1 outbreak so far has to a large extent spared that population."
Unlike seasonal flu vaccine, the federal government has bought the potential H1N1 vaccine, and it will decide whether to distribute it to state and local health authorities, who will probably do both public and private distribution and perhaps much faster than normal, she said.
"This is different from seasonal influenza because we may be trying to vaccinate a lot of people relatively quickly, particularly if disease increases early this year, when kids go back to school and so forth," Dr. Schuchat said. "We want to remove the barriers."
Emory is one of eight sites conducting clinical trials of the new vaccine, which will be tested first in adults and then in children. Emory will be looking at the safety of the vaccine and whether it needs to be given in two doses, as usually happens with a relatively unknown influenza strain, said Mark Mulligan, professor of medicine at Emory and director of the Vaccine and Treatment Evaluation Unit.
The clinical trials will also look at whether the H1N1 vaccine can be given in conjunction with seasonal flu vaccine.
The trials will likely begin in the second week of August, with a second dose administered 21 days after the first dose, and antibody testing eight days and 21 days after each dose, Dr. Mulligan said.
"I think it will be mid-September by the time we have the most important data, maybe late September," he said. The first four clinical trials at Emory will include about 300 people, from ages 6 months up through seniors, but later trials could involve hundreds more, Dr. Mulligan said.
"We're pleased that Atlanta and Georgia have a chance to contribute to this national effort to prepare our nation for the potential return of the pandemic virus, in terms of vaccine readiness." he said. "It's something that we're happy to have the chance to do."
Reach Tom Corwin at (706) 823-3213 or firstname.lastname@example.org.
PRIORITY FOR VACCINATION
The Advisory Committee on Immunization Practices to the CDC recommended the vaccine be targeted to five major groups:
- Pregnant women
- Those who live with an infant younger than 6 months
- Health care workers and emergency medical services personnel
- Those 6 months to 24 years old
- Adults with underlying health problems that put them at greater risk for complications from flu, such as diabetes or lung disease