WASHINGTON, DC—The effort to get ahead of the spread of the H1N1 flu epidemic has been a story of two steps forward and one step back, agency leaders told legislators in October. The good news is that the virus has not experienced any widespread mutation, so the targets used in the current vaccine are still viable and efficacious. On the other hand, problems on the production line significantly hampered vaccine creation in the early stages, resulting in fewer available vaccines than what was predicted for the end of October.

Concern Over Delays, Flu Severity

On October 21, the Secretaries of Health and Human Services, Homeland Security and Education met with the Senate Homeland Security Committee to update them on the situation. At that time, there were 2,300 reported deaths in the US attributable to H1N1 since April. Additionally, half of flu hospitalizations have been for people under the age of 25. Children, the elderly, and pregnant women have also been severely effected. As of that date, 100 pregnant women had needed intensive hospital care due to the H1N1 virus, and 28 had died.

Last month, over 6% of all hospital visits in the US were attributed to the flu. This is an increase compared with the peak of last winter’s seasonal flu outbreak, which occurred between January and April. Typical flu activity in October ranges around the 1% mark for hospital visits. “This particular strain has moved with alarming speed and taken a significant toll during a time of year when we don’t see many cases of the flu,” declared Committee chair Sen Joseph Lieberman, I-CT. “I’m concerned that the flu’s spreading so rapidly and in some cases so intensely that it’s getting ahead of the federal public health system’s ability to respond to it.”

He noted that the Department of Health and Human Services was expecting to have 25-30 million vaccines by the end of October. This is less than the 40 million projected when the vaccine production process began. Sen Lieberman also voiced concerns about hospital overflow. Citing a model that projected 35% ofAmericans sick with H1N1, he noted that there would be 1 million sick in Connecticut alone, and 17,500 hospitalized. That represents 150% of the state’s hospital bed capacity.

Production Catching Up

HHS Secretary Kathleen Sebelius responded with guarded optimism regarding the nation’s ability to keep ahead of the epidemic. “The good news is the virus has not changed significantly since April, which means the vaccine target is appropriate. It’s getting a robust response. Except for a few cases that seem to be outliers, the virus seems to be susceptible to Tamiflu,” Sebelius said.

In addition, the delays that have put vaccine production behind projections were short-term and have been fixed. For example, Sebelius pointed out that one production line recently activated by the manufacturer had technical difficulties that were addressed, and the line is now up and running at proper capacity. Another delay was caused by lower antigen yields using outdated egg-based vaccine development technology. “Producers are still using old technology, still using that egg-based [technology],” Sebelius said. “We’re committed to developing cell-based technology. We need to make all aspects of the manufacturing prospect appropriate for the 21st century.”

The delays have been offset somewhat by the vaccine initiating a rapid, robust immune response, Sebelius noted. Previous estimates had predicted that many people would need a two-dose regimen, with a gap between doses and a total of 36 days between first dose and immunity. The vaccine has shown to produce immunity within 8 to 10 days, with everyone over the age of 10 only needing one dose. “Right now we are at a point where the demand is ahead of the yield. The very good news is that we have a distribution contract that gets the vaccine on a daily basis to 150,000 sites,” Sebelius explained. “We will be allocating on a per capita basis to states; states can order daily; every day that they come in, we’re pushing them out the door.”

As for the rising number of infections observed throughout October, Sebelius said that she expects that figure to continue to rise until the vaccination program reaches full effectiveness and immunity begins to slow the new infection rate. Questioned about a report released by Purdue University saying that the infection rate will peak in late October, before most Americans will be able to get a vaccination, Sebelius responded, “I’d suggest though that we are at the very beginning of seasonal flu, and what we anticipate is a rise and not a dropping off. Even if people experience flu early in the spring or the fall to go ahead and get the vaccine, because as different strains develop during the flu season, it will immunize them from what is to come.”

Most Troubling CasesT

he unusually high death rate in children, with 86 pediatric deaths since April, remains a serious concern for government health officials. “That number is equivalent to the entire flu season of past years in lab-confirmed deaths of children,” Sebelius declared. “This is much different than regular flu, when 90% of deaths are people over the age of 65.” Many of HHS’s education programs have been directed to children, with emphasis on simple hygiene lessons— for example, sneeze and cough into your arm and not into your hand. Consequently, children are learning to adhere to basic hygienic principles much better than adults. “They are listening to Elmo and teaching their parents,” Sebelius said.

However, for children who are already sick, it may become important for pediatric antivirals to be in ready supply. Prior to the flu outbreak, there was an overall shortage, so HHS has taken steps to release 75% of its stockpiles. The agency has also published guidelines instructing pharmacists on how to compound the antiviral pills with syrup for children too young to swallow pills.

There is also a concern about the need for intravenous antiviral medication for the sickest of hospitalized flu patients. The Food and Drug Administration and Centers for Disease Control are working together to examine candidate drugs. Several candidates are in the final stages of testing and a decision by FDA is imminent. “We hope it’s a matter of days,” Sebelius said. Though full clinical trials have not been completed on the drugs, FDA has the authority to give them an Emergency Use Authorization, making them available to the public due to necessity.

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