H1N1 Vaccine Production Lagging Behind Expectations

The CDC told its Advisory Committee on Immunization Practices, or ACIP, in late July that it hoped to have 120 million doses of vaccine for the novel influenza A (H1N1) virus available by October. Manufacturing issues, however, have slowed production of the new vaccine, and federal officials now expect only about 45 million doses to be available by mid-October.

According to HHS spokesman Bill Hall, 20 million more doses should be available each week thereafter.

"There's no shortage," Hall said in an Aug. 18 interview with AAFP News Now. "It's simply a delay, which will push it back about four weeks."

The ACIP planned for such circumstances during its July meeting, recommending that several groups receive the vaccine before others if supply is limited:

CDC officials have said the prioritized groups include about 42 million people.

"We believe we'll have enough for the priority groups that have been identified," Hall said. "People in those groups should talk with their doctor or health care provider about the vaccine."

Jonathan Temte, M.D., Ph.D., a professor in the department of family medicine at the University of Wisconsin School of Medicine and Public Health, Madison, and a member of the ACIP, said physicians should take time to identify health care workers and patients in their practices who fall into priority groups.

When vaccine becomes more widely available, the ACIP has recommended that, in addition to the groups listed above, all health care and emergency services personnel receive the vaccine, as well as individuals 4-24 years of age and individuals 25-64 years of age who are at increased risk from novel H1N1 because of chronic health conditions or compromised immune systems.

All of the recommended groups together include about 159 million people, or more than half the nation's population.

Of course, there's no guarantee that everyone in those groups will want the vaccine. The CDC recommends the seasonal influenza vaccine for more than 80 percent of Americans, but less than 40 percent of the population is vaccinated each year.

Temte said it was difficult to predict how much demand there will be for the new H1N1 vaccine. He said the severity of the disease -- including rates of morbidity, mortality and hospitalization -- will be one critical factor driving demand.

"We'll know by the middle of October," he said. "As soon as we have children back in school, we're going to see this thing take off again."

The mainstream media also could influence demand. An Aug. 15 article in a British tabloid claimed that the new vaccine has been linked to Guillain-Barre Syndrome, or GBS, and reported that public health officials in the United Kingdom have asked neurologists to be alert for cases of GBS triggered by the vaccine.

The article also refers to the new vaccine as "similar" to the swine flu vaccine that killed more than two dozen Americans in 1976.

Temte said that asking neurologists to conduct surveillance with a new vaccine is merely a precautionary measure, and he added that the new vaccine is not antigenically similar to the 1976 vaccine.

"They're very distinct viruses," he said.

Supply and demand also will be affected by how many doses are called for and how much antigen per dose is needed.

The H1N1 vaccine is expected to be administered as a two-dose series, but Hall said clinical trials are ongoing to address that issue, as well as to determine whether or not adjuvant will need to be used to increase the vaccine's immunogenicity.

Hall said physicians interested in administering the new vaccine should be proactive in contacting their state or local health officials. The CDC offers an online resource that can help physicians contact state and, in some cases, local health departments.

"As soon as we receive vaccine, we'll be shipping it out to the states," he said.