Posted on 11/16/2009 12:23:01 PM PST by decimon
WHAT: A new study shows that molecular similarities exist between the 2009 H1N1 influenza virus and other strains of seasonal H1N1 virus that have been circulating in the population since 1988. These results suggest that healthy adults may have a level of protective immune memory that can blunt the severity of infection caused by the 2009 H1N1 influenza virus.
The study team was led by Bjoern Peters, Ph.D., and Alessandro Sette, Ph.D., of La Jolla Institute for Allergy and Immunology, Calif., grantees of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
The investigators looked at molecular structures known to be recognized by the immune system—called epitopes—on 2009 H1N1 influenza and seasonal H1N1 viruses. Viral epitopes are recognized by immune cells called B and T cells: B cells make antibodies that can bind to viruses, blocking infection, and T cells help to eliminate virus-infected cells.
Using data gathered and reviewed from the scientific literature and deposited into the NIAID-supported Immune Epitope Database and Analysis Resource (www.iedb.org), the investigators found that some viral epitopes are identical in both the 2009 and seasonal H1N1 viral strains. Those epitopes that could be recognized by two subsets of T cells, called CD4 and CD8 T cells, are 41 percent and 69 percent identical, respectively. Subsequent experiments using blood samples taken from healthy adults demonstrated that this level of T-cell epitope conservation may provide some protection and lessen flu severity in healthy adults infected with the 2009 H1N1 influenza virus.
Analysis of the database also found that among six viral surface epitopes that can bind antibody, thereby preventing infection, only one is conserved between 2009 and seasonal H1N1 viral strains.
These results suggest that healthy individuals may have immune memory that recognizes the 2009 H1N1 strain and therefore can mount some measure of an immune attack. The findings also may help explain why the 2009 H1N1 influenza pandemic affects young children more severely than it does healthy older adults and also why two H1N1 vaccinations are needed to protect children ages nine years and under.
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ARTICLE: J Greenbaum et al. Pre-existing immunity against swine-origin H1N1 influenza viruses in the general human populace. Proceedings of National Academy of Sciences. DOI: 10.1073/PNAS.0911580106 (2009).
WHO: Allison Deckhut-Augustine, Ph.D., Chief, Immunoregulation Section, Basic Immunology Branch, NIAID Division of Allergy, Immunology and Transplantation, is available for comment.
CONTACT: To schedule interviews, please contact the Julie Wu at 301-402-1663, wujuli@niaid.nih.gov.
NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.
The National Institutes of Health (NIH)—The Nation's Medical Research Agency—includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.
When I saw it was the U of R that developed the vaccine, I was more convinced then ever of a great "social experiment".
I think the U of R has been doing "dirty work" for years with lotsa ginea pigs in their hospital.
I didn’t know there is a seasonal H1N1.
I feel like I’ve been hit by viral arthritis, arthritic aches and pains, sluggishness, no energy, can’t get comfortable, but not quite sick. Maybe this is me telling H1N1 to go away.
I usually do not get severe flu symptoms. I'll get some mild symptoms of what could be a cold or a flu or whatever.
Why do I get the feeling some people are a little dissapointed this H1N1 hasn’t turned into a full blown, with mass hysteria outbreak as of yet? I could be jumping the gun but it all sounds like a lot of hype to me.
I heard or read somewhere that H1N1 was manufactured, not naturally occuring, so, by who? and why? I guess we were suppose to get much sicker than we are....oops.
I was diagnosed with swine flu a week ago today, got Tamiflu and by Thursday I was back to my regular self. It wasn’t that bad but it might have been w/o the Tamiflu.
What doesnt kill me only makes me stronger?
I'm betting that several older folks have died but this is about "youth". Older folks should die, right???
The flu happens every year and deaths are not announced. This H1N1 is a great social experiment.
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