v/v represents the volumes of active ingredients to the volume of solution, i.e. an abbreviation for "by volume," used in chemistry and pharmacology to describe the concentration of a substance in a mixture or solution. Thus 2% v/v means that the volume of the substance is 2% of the total volume of the solution or mixture. See also w/v.
According to New Zealand, "One standard drink equals 10 grams of pure alcohol," i.e. one regular can of beer has about 50 times the total daily average dose consumed with Sativex, depending on the actual ethanol content and volume. Give me a break.
The control group received it as well. Curiously the theory that THC acts on the same pathway as opium in the study supports the medical use of pot.