The A/H1N1 flu virus found in some Brazilian victims of the disease is a mutated version of the virus isolated in the United States, the Sao Paulo State Health Secretariat announced on Tuesday.

According to the secretariat, Brazilian scientists discovered the mutation by mapping the genetic sequence of the virus collected from the first patient infected in Sao Paulo State.

The new variant, which was named Influenza A/Sao Paulo/H1N1, has a mutation in a protein called hem agglutinin, which is responsible for the virus' capacity of invading human cells.

According to the Brazilian scientists, the genetic mapping will be valuable to find out whether there have been other variations of the H1N1 flu virus in the world, and also to produce a vaccine for the virus.

The scientists need now to analyze the samples taken from other patients in order to develop the best vaccine to fight the most common variety of the H1N1 flu virus.

However, the differences between the Brazilian variation and the virus isolated in the United States is very small, which means that there is a good chance that a vaccine developed from the US virus works in the Brazilians as well.

According to the scientists, variations are very common in influenza viruses. They do not know yet whether the mutation made the H1N1 flu virus weaker or stronger.

There are 74 people infected with the H1N1 flu in Brazil, 27 of whom are in Sao Paulo State.

(Xinhua News Agency June 17, 2009)