Sunday, November 29, 2009

vaccine ineffective against lethal virus mutation

Examiner | One sample of the Ukraine flu virus has been classed as a low reactor to the H1N1 vaccine. If this mutation spreads, it could result in infection for people who have been vaccinated against the swine flu. Other mutations that have been identified include Tamiflu resistance and complete destruction of the lungs.

Virus mutation and reaction to flu vaccines

Vaccines are created to respond to each different type of virus, and must be adapted if the virus changes too much from the original. Influenza viruses are highly susceptible to mutation, which explains the requirement for a new seasonal flu vaccine each year. When a vaccine provides a strong immune response to a virus, that virus is considered to be a high reactor to the vaccine. In the event that the virus mutates to the point where the vaccine provides a limited or nonexistent level of protection, it is considered a low reactor.

H1N1 mutation and the swine flu vaccine

The samples of the Ukraine flu virus that were analyzed by the World Health Organization provide a great deal of information about the mutations found in this strain of the swine flu. For example, each of the samples from fatalities contained a change in the receptor binding domain for the virus to D225G, which affects the lungs. In addition, one sample has been classed as a low reactor, which means that if that strain of virus were to spread, individuals who have been vaccinated would not be protected.