US needs more effective flu shots, experts say
In the midst of an early flu season, public health officials are urging unvaccinated people to get a flu shot, as the best step they can take to protect both themselves and their families.
Yet the Centers for Disease Control and Prevention also acknowledged Friday that influenza vaccines, on average, are only about 62 percent effective. In the past, the CDC had estimated that flu shots were 70 percent to 90 percent effective.
"There is a growing consensus among the public health communities that we need better influenza vaccines," says Michael Osterholm, director of the Center for Infectious Disease Research and Policy. "We're operating largely in the 1950s for our flu technology.
Osterholm last year published an influential analysis in The Lancet showing that, according to very rigorous standards, evidence indicated that flu shots were less effective than commonly reported. For children and seniors over age 65, there was no rigorous data showing their efficacy at all.
One subset of patients does get high protection from flu vaccines, Osterholm found. The intranasal flu vaccine, sold as FluMist, protects 83 percent of children under 8. There's mixed evidence about how well FluMist protects adults over 60, and a lack of evidence on its effect in people ages 8 to 59.
In general, "The flu vaccine is a good vaccine, but not a great vaccine," says William Schaffner, a professor at Vanderbilt University School of Medicine.
Osterholm says he strongly believes people should get yearly flu vaccines, given their good safety record. And he says "moderate" protection is better than no protection at all.
But drug companies have felt little pressure to make truly "game-changing" vaccines, Osterholm says, because experts and the public have believed that current shots are adequate.
"The No. 1 deterrent to getting new flu vaccines is the perception that the current ones are good enough," says Osterholm, also a professor at the University of Minnesota School of Public Health.
With relatively low efficacy, the flu shot today doesn't have much power to produce true "herd immunity," Osterholm says. Herd immunity is achieved when enough people are immunized with an effective vaccine that the community's viral load drops, protecting even the unvaccinated.
Joseph Bresee, chief of the CDC's epidemiology and prevention branch in its influenza division, said Friday that "there's lot of research going on toward improving vaccines," noting that "the goal is to create a vaccine that you don't have to give every year that works better."
Today, people need to be revaccinated every year against the flu. That's because the influenza virus is constantly changing. Virologists try to predict which viruses will be in circulation in the coming season, hoping to get a good "match" between the viruses in the community and the viral strains used in the vaccine.
A "game-changing" vaccine would be very different.
Such a vaccine would produce immunity by including parts of the influenza virus that don't change from year to year, and which are common among many strains of virus, Osterholm says. These vaccines should also protect people for a decade or more, stimulating the immune system to recognize flu viruses that it hasn't encountered for a long time.
In a 2011 interview with USA Today, National Institutes of Health director Francis Collins said he was "guardedly optimistic" that a "universal" flu shot could be developed within about five years.
One such game-changing vaccine is being tested in the U.S. in an early phase one trial - the smallest and most preliminary type of human study - Schaffner says.
"It's clearly the holy grail," Schaffner says.
But the U.S. should be doing more to lead the way, Osterholm says.
Most vaccines in development today make only minor improvements, Osterholm says, relying on the same techniques used for decades. These vaccines produce immunity by using proteins found on a virus' outer coating.
Of the more than 170 influenza vaccines in clinical trials around the world, all but 13 are made in the traditional way, Osterholm says. None is supported by the U.S. government, he says.
Developing a next-generation flu vaccine could take 15 years and cost over $1 billion, Osterholm estimates.
Schaffner notes that significant improvements are already being made.
Next year's flu shots should provide slightly broader protection. The FluMist nasal spray will protect against four viral strains, instead of the current three. Manufacturers of flu shots are also working to include four viral strains.
Also, the Food and Drug Administration in November approved the first flu vaccine made in cell cultures, rather than chicken eggs. The vaccine, Flucelvax, made by Novartis, is approved only for adults.
Many European countries already use cell culture techniques, which allow companies to produce vaccine far more quickly, Osterholm says.
Cell-culture technology allows vaccine makers to respond rapidly to "urgent public health needs, such as a pandemic, within weeks," according to Novartis.
The United States' current system - a six- to nine-month process that relies on fertilized chicken eggs to grow viruses - is "archaic," says Robert Glatter, an emergency medicine physician at Lenox Hill Hospital in New York.
Yet while cell cultures will allow companies to manufacture vaccines much more quickly, it doesn't make the vaccine any more effective, Osterholm says.
And Glatter says companies face significant obstacles in developing innovative flu vaccines.
It's "quite difficult for private companies to embark on such an endeavor, in light of the U.S. government's strict policies toward approving vaccines," which must undergo rigorous tests for safety, Glatter says.
Drug companies may see little point in developing a universal vaccine, Glatter says. "If you get a mega-vaccine once every 10 years to prevent the flu, the flu vaccine market would essentially be down-regulated, with less financial market incentive."
Yet Glatter says 2009's H1N1 pandemic flu suggests that the human body is capable of producing extremely long-term immunity from influenza. Senior citizens had relatively low rates of infection during that outbreak, likely because they were exposed to a similar virus during the 1930s and 1940s, he says.
"The goal is to make a vaccine that can confer such long-term immunity," Glatter says. "Such a feat would be a real breakthrough."
A broadly protective flu vaccine might save lives during a pandemic, because many people would already have been vaccinated, Osterholm says. During the 2009 H1N1 pandemic, manufacturers required months to develop a matching flu shot.
But a universal vaccine would have its greatest impact in the developing world, Schaffner says. Many poor countries can't afford yearly flu shots. Far more people could be vaccinated if they only had to pay for a shot every 10 years, he says.
(c)2013 USA Today
Distributed by MCT Information Services
- Study suggests potential hurdle to universal flu vaccine development may be overcome Aug 15, 2012 | not rated yet | 0
- FDA approves flu vaccine for coming season Aug 14, 2012 | not rated yet | 0
- FDA approves first 4-in-1 flu vaccine Feb 29, 2012 | not rated yet | 0
- Study: Flu shot better than nasal spray in adults Sep 23, 2009 | not rated yet | 0
- NIH experts describe influenza vaccines of the future Nov 17, 2010 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Why is zone 1 in liver more prone to ischemic injury?
May 23, 2013 Hi, Is it because around central vein, there is only deoxygenated blood from the vein where as in the periphery there is hepatic artery. Also why...
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013 As title suggest. Thanks :smile:
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
- More from Physics Forums - Medical Sciences
More news stories
(AP)—Merck & Co. says it is ending development of an experimental Parkinson's disease drug because the drug wasn't working.
Medications May 23, 2013 | 1 / 5 (1) | 0
(AP)—Johnson & Johnson is developing what could eventually be game-changing treatments for depression and pain, and it's aiming to apply for approval of more than 10 new medicines by 2017, executives said Thursday during ...
Medications May 23, 2013 | 5 / 5 (1) | 0
An independent panel of experts on Wednesday recommended US approval of a new Merck sleeping pill called suvorexant, but expressed concerns over the highest dosage and risks of drowsy daytime driving.
Medications May 22, 2013 | not rated yet | 0
GlaxoSmithKline PLC says it's starting an unusual collaboration with the U.S. government to develop several antibiotics for both bioterrorism threats and bacterial infections resistant to current medicines.
Medications May 22, 2013 | not rated yet | 0
The new 13-valent pneumococcal conjugate vaccine (PCV13) appears to be as safe as the previous version used prior to 2010, the 7-valent pneumococcal conjugate vaccine (PCV7), according to a Kaiser Permanente study published ...
Medications May 22, 2013 | not rated yet | 0
(Medical Xpress)—A new study by researchers in the US has shown that an ancient virus can be modified to help in the fight against the simian immunodeficiency virus SIV, which is the equivalent in monkeys ...
17 hours ago | 5 / 5 (3) | 0 |
Two mutations central to the development of infantile myofibromatosis (IM)—a disorder characterized by multiple tumors involving the skin, bone, and soft tissue—may provide new therapeutic targets, according to researchers ...
12 hours ago | 3 / 5 (2) | 0 |
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
14 hours ago | 3.7 / 5 (3) | 0 |
Biological processes are generally based on events at the molecular and cellular level. To understand what happens in the course of infections, diseases or normal bodily functions, scientists would need to ...
15 hours ago | 5 / 5 (4) | 0 |
How can healthy people who hear voices help schizophrenics? Finding the answer for this is at the centre of research conducted at the University of Bergen.
17 hours ago | 4 / 5 (2) | 2
(Medical Xpress)—The way Alzheimer's disease is portrayed by advocacy groups and the media is having undue influence on the euthanasia debate, according to a Deakin University nursing ethics professor.
19 hours ago | not rated yet | 2