Manufacturing issues may limit the number of vaccine doses against novel influenza A(H1N1) that will be available when immunization programs begin around mid-October, officials from the Department of Health and Human Services told members of the National Biodefense Science Board in a public teleconference.
But clinical trial testing of the inactivated and live attenuated virus vaccines already are underway, and programs for distributing the vaccines and conducting surveillance should be in place when the vaccines are ready, the officials said.
Robin Robinson, Ph.D., director of the Biomedical Advanced Research and Development Authority of HHS, reported that, for the most part, vaccine production and testing are on schedule. All five vaccine manufacturers recently received their potency assay reagents so they can know how much vaccine they have produced. But an unanticipated difficulty in bulk production of the live attenuated virus vaccine has slowed its progress.
Although vaccination programs still are slated for mid-October, the number of doses that will be available by then has been lowered from 120 million to 45 million, with 20 million doses coming out each week afterward, Dr. Robinson said. The reduction in doses is a result of lower than expected vaccine yield, compared with previous yields with seasonal flu vaccines. One manufacturer also had obligations to produce vaccine for Australia ahead of other clients. Another manufacturer's difficulty in finishing up its orders of seasonal influenza vaccine has affected the time line for novel H1N1 vaccine production.
The federal government already has bought 190 million vaccine doses and, if needed, 120 million adjuvant doses. It also has stockpiled 84 million treatment courses of antivirals and another 3 million are expected to arrive soon. In May, states were able to purchase 11 million antiviral treatment courses; another 2 million have been recently purchased, he said.
The National Immunization Survey will be set to begin collecting immunization data as early as Oct. 10 for weekly reports of national coverage estimates. While clinical trials will provide data on reactogenicity to the vaccine, rare adverse events will be monitored through the Vaccine Adverse Event Reporting System and the population-based Vaccine Safety Datalink. Vaccine safety in the military will be collected though the Defense Medical Surveillance System, a collaboration between the Department of Defense and the Food and Drug Administration. A special surveillance program also will be set up for Guillain-Barré syndrome.
Dr. Daniel B. Jernigan, deputy director of the CDC's National Center for Immunization and Respiratory Diseases, noted that public health laboratories will focus their testing more on surveillance than clinical testing capacity.