The win will provide McCann with encouragement as it battles with its fellow Coca-Cola GB roster shop, Mother, in a bid to retain its Classic Coke account.
Vanilla Coke looks set to launch in the UK in May. It will initially be available in 500ml bottles and later sold both in cans and in two-litre bottles. It launched in the US last May, where it was a significant success for Coca-Cola - the company has shifted 90 million cases of the drink.
A US campaign for the Vanilla Coke brand, produced by Interpublic's Martin Agency, broke earlier this month. It featured the Pop Idol judge Simon Cowell and the Hollywood actor Chaz Palminteri. A second execution, featuring Missy Elliott, will break in April.
The success of Vanilla Coke in the US seems to have changed its main rival Pepsi's opinion about launching its own version of the product.
Despite this win, McCann's relationship with Coca-Cola has nosedived in recent months. Rumours that the company was looking to move its adbusiness out of the scandal-hit Interpublic were fuelled when its US account was moved from McCann-Erickson New York into WPP's Berlin Cameron/Red Cell.