The first step uses a bit of influenza DNA to get the patient's immune system to begin fighting off the flu, and then the protection is given a "boost" some time later by the second step, which can be either another bit of DNA or a conventional flu vaccine.
VOA: standard.2010.07.21
It's a simple bit of protection for them that will save lives.
Switching the peg to a basket of currencies that included, say, the euro and yen as well would give the Gulf states a bit more protection against oil-price swings, but it is hardly a perfect fit.