Also, if your already fighting cold harbor mobs then you are already almost through the main story of your faction. Once you are and you start venturing into the other alliance areas, it is much easier to find and contract vampirism in those alliances zones as there will be far fewer people competing for the bites and you won't haver to deal with the people who are scamming or spawn camping the mobs for profit. Way easier this way in my opinion.
Also, if your already fighting cold harbor mobs then you are already almost through the main story of your faction. Once you are and you start venturing into the other alliance areas, it is much easier to find and contract vampirism in those alliances zones as there will be far fewer people competing for the bites and you won't haver to deal with the people who are scamming or spawn camping the mobs for profit. Way easier this way in my opinion.