Feb 13, 2013 (CIDRAP News) – Top federal health officials who testified on Capitol Hill today said the nation has much better influenza defenses today than it had 10 years ago, but one of them predicted that a "universal" flu vaccine is probably still 5 to 10 years away.
Officials from the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) pointed to increases in flu vaccine production capacity and newly approved flu vaccines as signs of progress, but they also made clear that the goal of a vaccine offering broader, longer-lasting protection is still distant.
The hearing before the House Energy and Commerce Subcommittee on Oversight and Investigations focused on the current flu season and flu preparedness generally. The panel heard from CDC Director Thomas Frieden, MD, MPH, FDA Chief Scientist Jesse Goodman, MD, MPH, and Marcia Crosse, PhD, healthcare director for the Government Accountability Office (GAO). The session was webcast.
The hearing also featured some questions about the potential effects of the "sequester" budget cuts scheduled to hit in March. Frieden and Goodman vowed that their agencies will do the best they can but gave no specifics on how the cuts will be handled.
A lengthy quest
When one panel member asked Goodman how close scientists are to developing a universal flu vaccine, he replied that he is more optimistic than he was a couple of years ago. If some recent developments pan out, he added, "It's possible we could have some real leads in this direction in the next 5 to 10 years, but it's not something that's just on the horizon."
Later, Rep. Michael Burgess, MD, R- Tex., vice chairman of the committee, pressed Goodman further, saying that a universal vaccine was talked about in 2005. "How close are we?" he asked.
"Nature is very tricky and as this is a very crafty virus, so I'd be very hesitant to predict," Goodman replied. "I think the earliest we'd begin to see something with clinical benefit might be 5 to 10 years. . . . There's some exciting progress, but there's a ways to go."
"This is not for lack of trying, this is because this is a hard scientific problem," he added.
Burgess asked him if a universal vaccine is still a worthwhile goal. "Absolutely," he replied. "Can you imagine if we had a world where we didn't have flu pandemics?"
Existing flu vaccines target the head of the virus's hemagglutinin (HA) protein, which evolves constantly, requiring reformulation of the vaccine each year to keep pace with the circulating strains. The holy grail of flu vaccine development is a product that would target a part of the virus that is the same among different strains, so that one vaccination could protect against a variety of strains, including novel strains, for several years or longer.
The latest vaccines
In recent months the FDA has approved vaccines that mark advances in flu vaccine production technology, but they still target the HA head.
As Goodman noted in his written statement, Novartis's Flucelvax, approved in November, is the first US-licensed flu vaccine grown in cell culture instead of chicken eggs. And last month the FDA approved Flublok, made by Protein Sciences Corp., the first US flu vaccine made with recombinant DNA technology. The process uses an insect virus grown in insect cells to make the target HA.
Frieden, in commenting on the new vaccines and related developments in vaccine manufacturing, called them "useful tweaks but not breakthroughs in terms of a longer-lasting vaccine."
Goodman observed that Flucelvax eliminates the need for a large supply of eggs and may allow a faster startup of vaccine manufacturing, while Flublok doesn't require use of the actual virus to start production, which could be very important in the event of a pandemic.
Commenting on general flu preparedness, Goodman noted that the number of companies making flu vaccine for the United States has reached seven, versus only three a decade ago. The more than 140 million doses of vaccine produced this year represent "a dramatic improvement from a few years ago," he said.
Along the same lines, Crosse said CDC and global flu surveillance have improved in the past decade. "Across the board we are in much better shape than 10 years ago, but there's still room for improvement," she said.
But she added that surge capacity is still a big challenge: "Emergency rooms are flooded every winter with people with flu, norovirus, other kinds of infectious diseases. That capacity has not significantly improved."
Flu season past its peak
In an update on the current busy flu season, Frieden said activity has peaked and is beginning to decline, but will continue for several weeks. He added that hospitalizations of elderly people with lab-confirmed flu are about twice as high as usual.
"The flu shot is not as effective as we'd like and is less effective for the elderly," he said. The CDC recently estimated the effectiveness of this year's vaccine at 62% overall.
Noting that A/H3N2 is the dominant flu strain in the US this year, Frieden said that for unclear reasons, such seasons are harder on the elderly. That was the case in 2003-04 and in 2007-08, he added.
Goodman told the panel that this year's vaccine is well-matched to the circulating flu strains. "The issue is the severity of the virus and the number of unvaccinated people," he said.
He didn't mention recent suggestions that the match between the vaccine and circulating strains may be less important than generally supposed. For example, the 2009 pandemic H1N1 vaccine was very well-matched to the virus, yet its effectiveness was estimated at 56%.
Frieden told the panel that overall flu vaccine coverage this season is roughly 40%. "We'd like to see at least an 80% vaccination rate, and obviously higher is better," he said.
Impending budget cuts
Committee members noted that the automatic budgets scheduled to take effect Mar 1—unless Congress agrees on an alternative approach—will be 5.2% for the FDA and CDC. They asked the health officials how the cuts would affect their agencies.
Frieden said more than two thirds of the CDC's budget goes to state and local health departments, so they are likely to be affected. "With fewer resources we'd have less capacity to detect and respond [to outbreaks] and to develop better tools in the future," he said.
Goodman said, "A substantial cut . . . would affect our science and highly interactive review processes for new technologies. It would also affect our user-fee programs."
Burgess advised the health officials that their agencies should be able to adjust to lower budgets, just as businesses routinely do. "I think if you're not doing that in your agencies, I'd encourage you to do so. I felt obligated to make that editorial statement," he said.
Later, Rep. Kathy Castor, D-Fla., came to the agencies' defense, saying, "It's important to remember we've already cut the budget of the CDC and FDA. What you're doing is cutting into their core missions."
"We have a responsibility to the American public to get them vaccinated, to get them all the tools to ward off disease," she added. "It's just wishful thinking to say, 'You can accept more budget cuts and more budget cuts.'"
White House Office of Management and Budget officials have told senior federal science officials not to discuss budget cuts forced by the sequestration, according to a news story published today in Nature.
On another topic, Rep. Tim Murphy, R-Pa., chair of the committee, said the panel is awaiting FDA documents concerning the recent outbreak of fungal meningitis linked to injectable steroids. He said the committee sent a letter to FDA Commissioner Margaret Hamburg 2 weeks ago requesting all the FDA's relevant documents by Feb 25. He asked Goodman to remind Hamburg of the request.
House subcommittee hearing page
Jan 11 CIDRAP News story "CDC's early-season look finds flu vaccine 62% effective"
Nature News story on sequester