Zoonotic diseases, such as avian influenza, have a devastating effect on both human and poultry populations therefore, new antiviral strategies are vital in managing disease. This has led to a greater emphasis on the use of alternative vaccine approaches, including the use of recombinant subunit vaccines. However, at present many of these new vaccines perform inadequately and require the use of an adjuvant to enhance their efficacy. Nevertheless, currently existing adjuvants can have deleterious side effects, such as inflammation. With this in mind, safe alternative adjuvants are required. Cytokines are immune molecules with an intimate role in the control of infection and their ability to protect against disease has made them excellent candidates as naturally occurring therapeutics as well as vaccine adjuvants. Furthermore, the ability of some cytokines to augment immune responses to low doses of antigen and, similarly, to prolong immune responsiveness may be employed in strategies to reduce multi-dose regimes required for many existing vaccines. We have investigated the adjuvant activity of several different recombinant chicken cytokines to assess their potential to act as adjuvants to augment an antibody response to an antigen. Several cytokines were able to boost an antibody response and whilst these cytokines showed raised antibody levels, the efficacy of interferon lambda (IFN λ) was sustained for a longer period of time. IFN λ was able to enhance antibody titres up to 10 fold compared with no adjuvant. IFN λ was also able to double antibody titres achieved using interleukin 6 and interleukin 18 and this was maintained until completion of experiment at day 43. The observation that IFNλ may elevate antibody responses to antigen supports the further investigation of this cytokine and its potential use as a vaccine adjuvant.