The potent flu strain that has caused a rush on flu vaccine at doctors’ offices might be less of a threat were it not for flaws in the way such vaccines are made and distributed, experts say.
Because of the limitations, this year’s vaccine is in short supply and is not a perfect match to ward off the current flu strain. Yet many experts said those problems are avoidable if government and industry can fix a production system that has become inflexible and outdated.
“The system we have has been in place for 50 years, and it works pretty well, but this year is highlighting when it may not be the best thing,” said Dr. Bruce Gellin, director of the national vaccine program office for the U.S. Department of Health and Human Services.
State and federal health officials said Tuesday they are still gauging the severity of this year’s flu outbreak, which is not yet ranked as an epidemic nationally or in Illinois.
But the disease is off to a fast start nationwide, and federal officials said Tuesday that a rush in demand for vaccine has spurred them to consider seeking supplies from as far away as the United Kingdom.
Experts said most otherwise healthy patients who get the virus have little cause for worry.
“Most people who get [flu] will have that typical mild illness that’s annoying,” said Dr. Julie Gerberding, director of the federal Centers for Disease Control and Prevention. “They might miss a day of school or a day of work, but they will recover without incident.”
Nevertheless, Chicago-area municipal health departments reported getting hundreds of calls from people seeking dwindling supplies of vaccine. Many doctors offices and hospitals said they still have flu vaccine available, though some agencies said they are rationing their supply for patients who are 50 and older or have chronic health problems.
“We still are providing flu shots, but we are being very careful about who we give them to because of the shortage,” said Leslie Piotrowski, a spokeswoman for the Lake County Health Department.
A flurry of reports nationwide about some flu-related deaths of children has the CDC looking into whether this year’s dominant flu strain, called A-Fujian, might cause more severe disease in children.
Cook County officials said they are investigating the death on Monday of a 2-year-old Winnetka boy to see if he died of the influenza virus. An autopsy Tuesday was inconclusive.
Some deaths are to be expected. The number of confirmed deaths from flu or pneumonia in Illinois has ranged from 2,000 to 3,000 annually in recent years, often with one or two child deaths linked directly to the flu.
So far this year, a 90-year-old Lake County man is the only person in Illinois confirmed to have died of the flu.
The outbreak and the shortage of vaccine are putting a spotlight on methods of vaccine production and the choices that shaped the response to this year’s outbreak.
Those decisions were constrained in part by aging production methods that require months of lead time. For example, the viruses used to make vaccines are grown much as they have been for decades: in millions of chicken eggs.
Officials say possible long-term solutions include new technology that could allow faster production of genetically tailored vaccines. The government also is considering helping manufacturers offset costs of making extra vaccine.
“We’re looking at options that would help us have a surge capacity if we needed more vaccine,” Gerberding said.
The risk of nasty side effects may be somewhat higher this season, in part because the dominant A-Fujian strain belongs to the H3N2 group of flu viruses, which often carry an increased rate of complications.
But the threat from flu also is higher because this season’s vaccine was made not from A-Fujian but from a close relative called A-Panama. Experts said the vaccine should offer some protection against A-Fujian, though animal studies suggest coverage will not be perfect.
The decision not to use A-Fujian in this year’s vaccines was made last winter, as U.S. and international health officials made their annual analysis of flu cases from more than 100 global monitoring sites.
A-Fujian emerged late in the season in Australia and New Zealand, experts said. By that time it wasn’t feasible to include the strain in vaccines because the virus is difficult to grow in chicken eggs. Even with ideal conditions, that process takes eight months from the time the strains are selected.
Researchers must constantly monitor flu for changes that require tweaking the vaccine.
“The virus is able to fool us and stay one step ahead because it is able to change itself on almost a continuous basis,” said Dr. Robert Daum, an infectious diseases expert at the University of Chicago and former chairman of the vaccine advisory committee at the U.S. Food and Drug Administration.
Once it became clear that A-Fujian would not grow easily, the choice to go ahead with a related strain instead was a pragmatic one, said Gellin of the national vaccine program office.
“We knew we could create a vaccine for this season that might not be perfect, but if we waited much longer we might not have a vaccine at all,” Gellin said.
Making matters worse, vaccine producers cut back their output from last year, when a shortfall in demand meant that 12 million vaccine doses were simply thrown away. In a simple economic calculation, this year the vaccine producers made 83 million doses–12 million fewer than last year.
“It’s capitalism–they’re responsible to their stockholders, and they don’t produce a lot of vaccine in the first place,” Daum said.
Gerberding said the CDC is looking at ways of taking some risk out of the companies’ decisions about how much vaccine to make. One option is for the government to buy remaining doses at the end of flu season, encouraging manufacturers to make spare vaccine, she said.
But only fundamental strides in technology could make vaccine production agile enough to respond to a late-emerging flu strain, experts said.
“The goal is to rely on something other than the ability of a virus to grow in eggs,” said Dr. Anthony Fauci, director of the National Institute on Allergies and Infectious Diseases.
One alternative would be growing the virus in widely available cell cultures, which could allow a faster turnaround time, experts said.
Researchers also are looking at developing vaccines using a process called reverse genetics. That technique involves inserting the unique genetic traits of a viral strain directly into another virus that is easy to produce. Researchers at St. Jude Children’s Research Hospital in Memphis already have shown the method can work, though it’s still experimental.
Changing the basic production of flu vaccine probably will take an extended investment of research time and money, said Robert Lamb, a professor of molecular and cellular biology at Northwestern University.
“Right now there isn’t a simple way of changing the process that’s economic,” Lamb said.
