Avian flu in perspective: New England Journal article reviews 'spectacular' findings

November 23, 2005

ST. LOUIS -- An article by Robert Belshe, M.D., of Saint Louis University School of Medicine in this week's New England Journal of Medicine reviews recent "spectacular achievements of contemporary molecular biology" that hold great importance as the world prepares for a possible flu pandemic.

These achievements, including a recent genetic sequencing and recreation of the virus from the 1918 flu pandemic, "may enable us to track viruses years before they develop the capacity to replicate with high efficiency in humans," Belshe writes.

The new knowledge of the genetic sequences of influenza viruses that predate the 1918 epidemic will be "extremely helpful in determining the events that may lead to the adaptation of avian viruses to humans before the occurrence of pandemic influenza."

And as the virus continues to adapt, scientists now know what to look for. Belshe said scientists should conduct worldwide surveillance to monitor this adaptation process.

"It gives us some reassurance that by continuing to monitor the current virus in birds, we can get a sense as to when it'll be an efficient virus," Belshe says. "We may have some time to develop new vaccines and better therapies."

Belshe reviews recent articles in Science and Nature as part of his perspective article "The Origins of Pandemic Influenza â€" Lessons from the 1918 Virus."

The lead author of the research in Nature was Jeffery Taubenberger, M.D., Ph.D., of the U.S. Armed Forces Institute of Pathology, and the research in Science was led by Terrence Tumpey, Ph.D., of the Centers for Disease Control and Prevention.

"These recent research findings involving avian flu are startling, and they tell us that there are at least two mechanisms by which a pandemic influenza epidemic could emerge," Belshe says. "This research provides critically important insight into the origin of pandemic influenza."

Both mechanisms described in the articles were observed during worldwide pandemics of the 20th century. Scientists now conclude that the prospect of a new worldwide pandemic during the 21st century could involve either of two possibilities:

  • A direct spread of an entirely avian virus from birds to humans. This is what happened during the 1918 Spanish flu, the deadliest of last century's three pandemics.

  • A "reassortment" virus that mixes bird flu with already circulating human influenza strains to create a new strain. This was the case during the 1968 Hong Kong flu pandemic and the 1957 Asia flu pandemic. (Most of the flu strains of today are genetically related to the 1968 outbreak, which as a reassortment virus is genetically related to both the 1957 and 1918 viruses.)

    Belshe said the question of the moment involves which mechanism a future pandemic could involve. "Are we going to see an event like 1918, an avian virus adapting to man, or will it be an event like 1957 or 1968, where an avian virus contributes some genetic material by mixing in with a current strain of the human virus?" Belshe says. "We don't know what will happen or when it will happen, but we know it will happen."

    And although it can't be said for sure whether the current avian flu virus can adapt readily to the point where human-to-human transmission is possible, the recent research findings do provide some clues as to what genetic changes are necessary for such an event to occur. In fact, several additional genetic changes must occur in the currently circulating bird flu viruses before these viruses will begin to spread efficiently from person to person and this can be monitored closely by scientists.

    "Taubenberger estimated that based upon the rate of evolution, the 1918 epidemic had circulated in man since 1900," Belshe says. "So it took a while to become highly efficient as a pandemic virus."

    A copy of the full article can be found in the Nov. 24 issue of the New England Journal of Medicine (2209-2211).

    Belshe is director of the Center for Vaccine Development at Saint Louis University School of Medicine. He has conducted research related to influenza for more than two decades, and he has previously published articles in the New England Journal of Medicine on the influenza anti-viral Tamiflu, on the nasal spray influenza vaccine FluMist, and last fall on intradermal administration of flu vaccinations. He has authored dozens of papers on influenza that have been covered in various scholarly journals, including a 1998 commentary in The Lancet article that warned of a coming global flu pandemic and of the necessity of preparing for one.
    -end-
    Saint Louis University School of Medicine is a pioneer in geriatric medicine, organ transplantation, chronic disease prevention, cardiovascular disease, neurosciences and vaccine research, among others. The School of Medicine trains physicians and biomedical scientists, conducts medical research, and provides health services on a local, national and international level.

    (Editor's Note: To interview Dr. Belshe, please contact Joe Muehlenkamp at 314-977-8015. )

    Saint Louis University

    Related Influenza Articles from Brightsurf:

    Predicting influenza epidemics
    Researchers at Linköping University, Sweden, have developed a unique method to predict influenza epidemics by combining several sources of data.

    Common cold combats influenza
    As the flu season approaches, a strained public health system may have a surprising ally -- the common cold virus.

    Scent-sensing cells have a better way to fight influenza
    Smell receptors that line the nose get hit by Influenza B just like other cells, but they are able to clear the infection without dying.

    New antivirals for influenza and Zika
    Leuven researchers have deployed synthetic amyloids to trigger protein misfolding as a strategy to combat the influenza A and Zika virus.

    Assessment of deaths from COVID-19, seasonal influenza
    Publicly available data were used to analyze the number of deaths from seasonal influenza deaths compared with deaths from COVID-19.

    Obesity promotes virulence of influenza
    Obesity promotes the virulence of the influenza virus, according to a study conducted in mice published in mBio, an open-access journal of the American Society for Microbiology.

    Influenza: combating bacterial superinfection with the help of the microbiota
    Frenc researchers and from Brazilian (Belo Horizonte), Scottish (Glasgow) and Danish (Copenhagen) laboratories have shown for the first time in mice that perturbation of the gut microbiota caused by the influenza virus favours secondary bacterial superinfection.

    Chemists unveil the structure of an influenza B protein
    MIT chemists have discovered the structure of an influenza B protein called BM2, a finding that could help researchers design drugs that block the protein and help prevent the virus from spreading.

    How proteins help influenza A bind and slice its way to cells
    Researchers have provided new insight on how two proteins help influenza A virus particles fight their way to human cells.

    Eating elderberries can help minimize influenza symptoms
    Conducted by Professor Fariba Deghani, Dr. Golnoosh Torabian and Dr.

    Read More: Influenza News and Influenza Current Events
  • Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.