Navigation Links
1950s pandemic influenza virus remains a health threat, particularly to those under 50
Date:12/3/2013

(MEMPHIS, TENN. December 3, 2013) St. Jude Children's Research Hospital scientists have evidence that descendants of the H2N2 avian influenza A virus that killed millions worldwide in the 1950s still pose a threat to human health, particularly to those under 50. The research has been published in an advance online edition of the Journal of Virology.

The study included 22 H2N2 avian viruses collected from domestic poultry and wild aquatic birds between 1961 and 2008, making it the most comprehensive analysis yet of avian H2N2 viruses.

Researchers reported the viruses could infect human respiratory cells. Several strains also infected and spread among ferrets, which are susceptible to the same flu viruses as humans. Based on those and other indicators, one virus was classified as posing a high risk for triggering a pandemic.

Researchers found evidence the viruses were susceptible to current antiviral medications and could likely be controlled with an available prototype vaccine.

Such protection was unavailable in 1957 when an H2N2 virus that included genes from avian flu viruses emerged. Federal health officials estimate the 1957-58 pandemic killed 1 to 2 million people worldwide. While the H2N2 strain disappeared from flu viruses circulating in humans in 1968, it has persisted in the world's bird population.

"This study suggests H2N2 has the characteristics necessary to re-emerge as a significant threat to human health in part because most individuals under the age of 50 lack immunity to the virus," said corresponding author Robert Webster, Ph.D., a member of the St. Jude Department of Infectious Diseases. "This highlights the importance of continued surveillance of viruses circulating in animals and additional research to enhance our ability to identify viruses that are emerging health threats."

The research stems from the institution's role as a National Institute of Allergy and Infectious Diseases Center of Excellence for Influenza Research and Surveillance. St. Jude is also home to the only World Health Organization Collaborating Center focused on the spread of animal flu viruses to humans.

Historically, pandemic flu viruses arise when bird and human flu viruses swap genes. The mixing can result in novel viruses capable of spreading efficiently in humans and against which the human immune system is unprepared. "One school of thought regarding emerging flu viruses is that in more than 100 years, only three of the 18 subtypes of influenza A have caused pandemics. The H2 subtype is one," Webster said. The H2N2 viruses in this study remained genetically similar to the 1957 pandemic strain.

Along with being able to infect human trachea and other mammalian cells growing in the laboratory, five viruses also infected ferrets, according to researchers. Ferrets are a reliable model for studying flu's spread in humans. The five strains were among the nine H2N2 viruses that researchers tested in ferrets.

Three of the strains demonstrated a surprising ability to spread among ferrets housed in the same cage. The strains included the Dk/HK319/79 virus, which researchers classified as having high pandemic potential. The virus was isolated in 1979 from a duck in Hong Kong. The other viruses were classified as having low to intermediate pandemic potential. None of the viruses studied in ferrets spread via airborne transmission.

In addition, none of the viruses showed changes in the two viral proteins viewed as indicators of avian flu virus adaptation to human infection and transmission. Those markers are the hemagglutinin (HA) protein that the virus uses to infect cells and the PB2 protein, which is required for viral replication. The viruses in this study had HA and PB2 proteins with a preference for infecting avian, rather than human cells.

"While these viruses genetically look very avian, this study shows they can behave like mammalian viruses and replicate in multiple mammalian models of flu," said the study's first author, Jeremy Jones, Ph.D., a postdoctoral fellow in Webster's laboratory. "That is troubling because some of the original H2N2 pandemic viruses looked avian when the pandemic began in 1957, but in a few short months, all of the isolated viruses had picked up the genetic signatures of adaptation to humans. Our results suggest the same could happen if the H2N2 viruses again crossed from birds into humans."

Work is underway at St. Jude to identify other changes that are critical to the ability of avian flu viruses to infect and replicate in mammalian cells, Jones said.


'/>"/>

Contact: Carrie Strehlau
carrie.strehlau@stjude.org
901-595-2295
St. Jude Children's Research Hospital
Source:Eurekalert

Related medicine news :

1. hCGTreatments / Diet Doc hCG Diets & Weight Loss Plans Announces the Most Advanced Version of the 1950s hCG Diet Plans Designed to Produce Safe & Fast Weight Loss
2. Once-Banned Bird Flu Study Suggests Pandemic Threat Is Real
3. Pandemic H1N1 Flu Killed Far More Than Reported: Study
4. Measuring the uncertainties of pandemic influenza
5. Airports in N.Y., L.A., Hawaii Deemed Worst for Pandemic Spread
6. New influenza virus from seals highlights the risks of pandemic flu from animals
7. New technology combats global pandemic of drug counterfeiting
8. Most U.S. Schools Unprepared for Pandemics: Study
9. Many US schools are unprepared for another pandemic
10. Majority of US Schools not ready for next pandemic, SLU researchers say
11. Predicting, preventing, and controlling pandemics: Making the case for a strategic action plan
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/6/2016)... ... December 06, 2016 , ... The Touchpoint Solution’s new ... after launch. Almost 200 backers pledged more than $25,000 on Kickstarter ... , Dr. Amy Serin, an Arizona Neuropsychologist and inventor, says she feels like ...
(Date:12/6/2016)... ... 06, 2016 , ... Of the variety of ingredients in the food supply, ... contrary to common beliefs that hot dogs include “everything but the oink,” today’s wieners ... Ingredients combined with meat and poultry in a hot dog recipe can add flavor, ...
(Date:12/6/2016)... San Mateo, CA (PRWEB) , ... December 06, ... ... boost for their sports programs have until January 15, 2017 to apply for ... can be found at http://www.calcasathleticsgrant.com . Qualifying schools can receive up ...
(Date:12/6/2016)... , ... December 06, 2016 , ... ... is thrilled to formally announce its Not a Moment to Lose fundraising campaign. ... will rally supporters dedicated to declaring victory over cancer. The campaign aims to ...
(Date:12/6/2016)... ... 2016 , ... METTLER TOLEDO has launched its online ... papers, guides, handbooks, case studies, magazines, webinars, videos, catalogs, brochures, datasheets, user manuals, ... webinars and videos available online, visit the METTLER TOLEDO Expertise Library . ...
Breaking Medicine News(10 mins):
(Date:12/5/2016)... -- Spain Glaucoma Surgery Devices Market Outlook to 2022 ... Devices Market Outlook to 2022", provides key market data ... provides value, in millions of US dollars, volume (in ... Canaloplasty Micro Catheters and Glaucoma Drainage Devices. The ... for each of these market segements, and global corporate-level ...
(Date:12/5/2016)... NEW YORK , Dec. 5, 2016 Special ... collection of samples such as fluid and cells from organs ... advanced features, shapes, and sizes. The global market for special ... increasing geriatric population. In terms of revenue, the global special ... of 7.4% during the forecast period (2016–2026) and is expected ...
(Date:12/5/2016)... RATON, Fla. , Dec. 5, 2016 /PRNewswire-USNewswire/ ... Public Research (the Florida Institute) announced today ... LLC, an Orlando -based company ... The Florida Institute supports new company creation based ... for companies spinning out of Florida-based universities and research ...
Breaking Medicine Technology: