Spanish flu deadly 1918 virus reconstructed.
The deadly 1918 virus behind the Spanish flu has been reconstructed in an effort to predict future pandemics and develop new vaccines and treatments.
The virus, created by Adolfo Garcia-Sastre of Mount Sinai School of Medicine and colleagues, is contained at the Centers for Disease Control following strict safety conditions.
Three major discoveries about the virus, reported in the journal Science are:
It is extremely virulent in mice and leads to rapid death.
It is pathogenic in embryonated chicken eggs.
It grows very rapidly in human lung cells.
This contrasts with most flu viruses that infect humans, which generally aren't pathogenic in other species and grow much slower in human lung cells.
The virus was rebuilt using reverse genetics. Technique is as follows:
Mounts Sinai School of Medicine researchers received US patent number 6,544,785 for a technique they developed to create viruses from DNA. The technique, known as reverse genetics or Plasmid Rescue Technology, is specifically designed to work with viruses that use RNA for storing their genetic material. Influenza is one such virus.
The genetic makeup of influenza viruses allows frequent minor genetic changes, known as antigenic drift, and these changes require annual reformulation of influenza vaccines. Each year the World Health Organization (WHO) works with health agencies in many countries to identify the strain(s) of influenza spreading in human populations. Once the strain(s) is isolated development of a vaccine begins. The slowness of the process is problematic even under the best of conditions, but should a particularly virulent strain such as the one that caused the pandemic of 1918 arise, delays in vaccine production could be catastrophic.