Decision on smallpox vaccinations expected soon, Osterholm says

Nov 18, 2002 (CIDRAP News) – Now that the federal government has some licensed smallpox vaccine in its stockpile, a presidential announcement on vaccination recommendations may be coming very soon, bioterrorism expert Michael T. Osterholm, PhD, MPH, predicted last week.

"I believe that in the next days you'll be hearing from the president about this vaccine," Osterholm told healthcare workers at a meeting in Minneapolis.

Osterholm, a special advisor to Health and Human Services Secretary Tommy Thompson on bioterrorism and public health preparedness, made the comments Nov 15 at the annual conference on Emerging Infections in Clinical Practice and Emerging Health Threats, sponsored by the University of Minnesota and Minnesota Department of Health. Osterholm is director of the University of Minnesota Center for Infectious Disease Research and Policy (CIDRAP), publisher of this Web site.

The federal Advisory Committee on Immunization Practices (ACIP) recently recommended smallpox vaccinations for several groups of healthcare workers who could be assigned to care for smallpox patients in hospitals in the event of an outbreak. The committee estimated that those groups include roughly 510,000 workers nationwide, or an average of about 100 per hospital. In addition, the Department of Defense recently recommended that up to 500,000 US troops be inoculated against the disease. Recent reports quoting unnamed White House officials have said President Bush is likely to make a decision on those recommendations soon.

In October, the Food and Drug Administration (FDA) began licensing repackaged lots of Dryvax, the decades-old smallpox vaccine that has been the foundation of the national stockpile. The FDA action was necessary because the vaccine required a new diluent and new needles, the agency said.

Osterholm told the conference attendees, "We now have in this country 1.7 million doses of licensed vaccine. We will have potentially 8 to 10 million doses of licensed Dryvax by sometime in the middle of January." He said the original diluent for the vaccine had to be replaced because it had deteriorated.

Recent trials have shown that Dryvax can be diluted by 5 to 1 and still be potent. Osterholm said dilution of the entire supply of Dryvax could, theoretically, provide 50 million to 70 million doses. However, he told CIDRAP News that plans do not call for diluting the vaccine.

Osterholm also told the conference audience that the national stockpile includes about 80 million doses of smallpox vaccine made decades ago by Aventis Pasteur. "The potency is very, very good," he said of the vaccine. "The 80 million doses can also be diluted to give us upwards of 400 million doses." However, he said the vaccine cannot be licensed because the manufacturing records for it are inadequate. The FDA can permit the use of unlicensed vaccines and drugs under "investigational new drug" (IND) protocols that provide for patient consent and monitoring.

Osterholm said the expected recommendation on smallpox vaccination could soon be supported by liability protection, a reference to a provision in the homeland security bill that would protect healthcare workers who administer smallpox shots from being sued by recipients who suffer side effects. The federal government would assume any liability for adverse events, and plaintiffs could receive compensation for injury but no punitive damages. The provision was included in the bill passed by the House last week, and the bill is awaiting action in the Senate. The legislation would consolidate a number of federal agencies into a new Department of Homeland Security.

In response to a question, Osterholm said no licensed smallpox vaccine could be provided to the public right now. Besides the Dryvax and Aventis vaccines, HHS has 209 million doses of smallpox vaccine on order from Acambis and Baxter International, but he said that vaccine won't be licensed until 2004. In the event of a smallpox outbreak, "an IND product could given to the general public with about the same level of consent as a licensed product," he said.

Fielding another question, he said the number of staff members in each hospital who would be advised to get a smallpox shot is likely to vary widely. "What it boils down to is that each state needs to make a decision on who will be in that first group" to be vaccinated, he said.

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