Brazilian scientists reported on Tuesday that they have identified a new strain of the H1N1 virus after examining samples from a patient in Sao Paulo. It is not yet determined if the mutated form is more virulent.
Influenza viruses are notoriously plastic. They change quite readily, explains Dr. Ross. If you analyze the genome of the currently circulating flu virus you re going to find variability. So if the swine flu virus does mutate to become more virulent, it will most likely still contain many of the same antigens. The vaccine being developed and produced for this new H1N1 variant should still provide substantial protection, and it should still prevent a lot of cases.