> It's possible that it's very difficult to engineer a virus that can do better than anything nature has come up with
A lot of the debate was started because 2 groups did so in 2011, independently of each other finding mutations that allow the deadly H5N1 virus to transmit via air[1][2]. One group also did work to model the chance of these mutations showing up in nature[3]. The techniques by which to do this are fairly well established. Knowledge of how to do it safely is fairly limited, as is access to animals in which to test these modifications.
A lot of the debate was started because 2 groups did so in 2011, independently of each other finding mutations that allow the deadly H5N1 virus to transmit via air[1][2]. One group also did work to model the chance of these mutations showing up in nature[3]. The techniques by which to do this are fairly well established. Knowledge of how to do it safely is fairly limited, as is access to animals in which to test these modifications.
* [1] https://www.nature.com/articles/nature10831 * [2] http://science.sciencemag.org/content/336/6088/1534.long * [3] http://science.sciencemag.org/content/336/6088/1541.full