Sunday, February 18, 2007

Bird flu immunity?

It seems that many people may be immune to bird flu despite wide concern amongst scientists and a level of panic from various Governments since an outbreak of bird flu in south east Asia spread to neighbouring countries in 2004. The fear has been (and still is) that the H5N1 strain of avian influenza could create a pandemic, killing millions of people.
Research on mice and humans has found that people have a natural resistance to various flu strains and this could include immunity against bird flu.
Researchers at St Jude's Children's Research Hospital in Tennessee say that seasonal human flu (H1N1) and bird flu contain a related disease agent, neuraminidase (N1) . People who are immune to the human version could have a similar resistance to bird flu.
The researchers wondered if people infected with one strain of influenza might have partial immunity to another strain. No one has complete immunity, because flu can infect the same person over and over again.
But maybe there is just enough there to keep the new infection from being deadly.
Researchers tested blood samples from 38 human volunteers and their ability to inactivate neuraminidase from the human N1 virus and two H5N1 viruses. Most of the samples were active against the protein from the human flu virus, with eight of nine inhibiting the protein from both H5N1 strains.
The conclusion was that many people may be naturally immune to the effects of avian influenza.
The US National Institute of Allergy and Infectious Diseases described the research as "tantalising" but said that further work was needed to demonstrate real protection against avian flu.