BEIJING, May 17 (Xinhua) -- Scientists around the world have made several breakthroughs in studies on the Influenza A/H1N1 virus since the outbreak of the new deadly flu strain in North America.

    On Friday, World Health Organization Director-General Margaret Chan warned against a false sense of security from waning, saying there remained "great uncertainty" about the new strain that continues to spread.

    On gene sequencing of the virus, Canada's National Microbiology Laboratory announced on May 6 that they have analyzed three sample viruses taken from the cases detected in the country, becoming the world's first to unravel the gene sequence of the H1N1 virus.

    Finding the genetic sequence could open the door for scientists to know where the virus originated, how it evolved and how it spread, and it could also help develop a specific vaccine for the disease.

    U.S. researchers have found that the current A/H1N1 virus lacks most genetic markers of influenza infection severity identified from past outbreaks.

    Jonathan Allen and Tom Slezak from Lawrence Livermore National Laboratory found 17 genetic markers in the A/H1N1 virus, only half of the 34 identified from the past pandemic flu strains. The study suggests that the current virus may not be as dangerous as feared, while more studies are still required before any firm conclusions can be drawn.

    Masato Tashiro, head of the influenza virus research center at Japan's National Institute of Infectious Diseases and also a member of a WHO panel on the epidemic, has found that the virulence of the new strain of A/H1N1 virus is around the same level as that of normal seasonal influenza, but it is highly contagious compared with the normal seasonal ones.

    On immunology studies, researchers from University of Rochester in the U.S. developed a mathematical model to predict the immune response to infection with A/H1N1 flu viruses. The model, generating immune response scenarios reflecting multiple variables, found that antiviral therapy is most effective in stemming the spread of the virus when given within two days after infection.

    Rapid tests for the A/H1N1 flu have been developed in several countries.

    Japan's National Institute of Infectious Diseases said late April that it will take only six hours to detect the A/H1N1 virus by mixing its newly-developed reagent with mucus taken from the testee's throat.

    France's Pasteur Institute developed its rapid test for the A/H1N1 virus based on a standard laboratory procedure called PCR, or polymerase chain reaction. The process can find bits of genetic material that are unique to the virus, then reproduce them in large quantities for easy identification.

    Chinese researchers have also developed a rapid test which could detect the A/H1N1 flu virus within 12 hours.

    Meanwhile, a pandemic vaccine based on the swine flu virus could be available in four to six months, once companies receive the "seed stock" from WHO. It is currently being developed by the U.S. Centers for Disease Control and Prevention and is expected to be ready in the next few weeks.

    On Thursday, WHO held talks with vaccine manufacturers and other experts on issues as to when A/H1N1 flu vaccine production should begin, how many doses will be needed and who should get the vaccines.

Special Report:  World Tackles A/H1N1 Flu