The prospect that Americans will receive the swine flu vaccine in time to protect them from this second wave of the U.S. epidemic continues to dim. With the pandemic virus showing "widespread activity" in 47 states—six more than a week ago—the Centers for Disease Control and Prevention now concedes that many people will become infected before they have a chance to get the shot. "The vaccine will arrive too late for many," CDC Director Thomas Frieden said at a press conference this afternoon. But he noted that a third wave of disease may occur next winter, by which time there should be ample vaccine available.
Last week, Anne Schuchat, director of CDC's National Center for Immunization and Respiratory Diseases said 28 milion to 30 million doses might be ready by the end of October—a significant downward adjustment from the more than 40 million that Health and Human Services Secretary Kathleen Sebelius had predicted 3 weeks earlier. Although Frieden declined to make new projections for the weeks and months ahead, even those 28 million now seem unlikely. During the past 7 days, the number inched up from 11.4 million to 16.1 millions doses.
Frieden, who called the delays "enormously frustrating," said manufacturers have difficulty growing the viruses used to make vaccine. "Even if you yell at them, they don't grow any faster," he said.
Nicole Lurie, the assistant secretary for preparedness and response at HHS explained the delays to ScienceInsider in more detail, noting that the government has been weathering something of a perfect storm of unforeseen problems. HHS contracted with five companies to make vaccines. Only one, MedImmune, makes a live but weakened version of the virus, which is a different manufacturing process than the killed version. MedImmune has supplied product close to the predicted schedule, but it only is contracted for 12.8 million doses of the 251 million ordered. The other four companies—CSL Biotherapies of Melbourne, Australia; Sanofi Pasteur of Lyon, France; GlaxoSmithKline of London; and Novartis of Basel, Switzerland—have had different issues.
For proprietary reasons, Lurie would not name the delay issues at each manufacturer, but said “one company was just really overoptimistic” in its delivery predictions to HHS. Initially, all of the makers of inactivated vaccine had trouble with the “potency assay” used to ensure that 15 micrograms of influenza antigens are present in each dose. Once that was corrected, said Lurie, this company lost 20% to 35% of its antigen during the “recalibration.” Unfortunately, said Lurie, the company did not notify HHS of the problem. “They thought they were going to compensate by getting their yield up but they never let us know,” she said. “When we learned of problem, it was over and there was nothing we could do, which is too bad because we could have helped.”
After Columbus Day on 12 October, HHS learned about delays at two of the other companies. One had a new production line to fill doses of vaccine into individual syringes. “Getting up the new production lines with prefilled syringes was really slow,” Lurie said. The third company had “major production problems” that Lurie said she could not describe in detail for proprietary reasons. Basically they had difficulty making “acceptable” vaccine that did not contain an immune booster called an adjuvant, which is used in several countries but not the United States.
The final company wanted to supply its own country with vaccine before shipping product to the United States, which Lurie said would begin next week. She did not identify the company, but Australia's CSL earlier said it would supply its country before exporting the product.
In response to questions about safety, Frieden stressed at the press conference that these companies are using the same processes to make the novel H1N1 vaccine that they use each year to make 100 million or so doses of seasonal product. But if they have so much experience making the product, why so many snafus with the pandemic vaccine? “Almost every flu season, something goes wrong,” said Lurie, emphasizing that she was referring to manufacturing, not safety.
Although Frieden explicitly refused to make predictions about future supply of the pandemic vaccine, Lurie said that HHS will tell state health officers later today that the government expects to have another 10 million doses available next week. In subsequent weeks, projections are now that manufacturers will supply 8 million to 10 million doses per week. But Lurie concluded with a caveat that has become the mantra for the U.S. government during this pandemic: “It’s hard to predict week to week.”