One of the things that scientists have looked at is the cross protection of the different genotypes.If, for example, genotype 2 which is virulent and traveling around the world can be prevented by vaccination with a genotype 1, which is less virulent and more stable then perhaps there's an opportunity to use that genotype 1 to dampen or even prevent genotype 2.
What scientists have found out is that that doesn't happen.There's not cross protection between the genotypes so the issue of our vaccinations being effective against genotype 2 when there's a recombination of 1 and 2 is still a major question.We don't know that.It hasn't been tested.
If the current vaccine prototype has some efficacy and safety against the genotype 2 it's not known at this yet if they'd be just as safe and just as effective against any recombination and if not, that could give an opportunity for this new recombinant virus to continue to spread and continue to cause trouble.
Dr. Sundberg says this recombination could result in a virus that's as transmissible as genotype 2 while being less virulent and more difficult to detect than would be genotype 2 by itself.
Source : Farmscape.ca