The purpose of the study is to obtain two year follow up data for subjects that received six vaccinations of NicVAX in prior phase III studies. No treatment will be administered. Anti-nicotine antibody levels and safety data will be collected.

This study will follow subjects that participated in the NicVAX phase III studies for a second year. These predecessor studies, Nabi-4514 (NCT#00836199) and Nabi-4515 (NCT#01102114) evaluate the efficacy and safety of 6 vaccinations of NicVAX or placebo as an aid to smoking cessation. The two phase III studies are one year in duration, and subjects who complete these studies are eligible to enroll in Nabi-4522. As the phase III studies are ongoing, subject assignment to NicVAX or placebo will remain masked. No intervention will be administered in Nabi-4522. Subjects will be followed for immunogenicity (anti-nicotine antibody level)and for safety.

Inclusion Criteria:

• Subjects who agree and sign consent to participate in this follow-up study.
• Subjects randomized and completed month 12 of the Nabi-4514 or Nabi-4515 study.
• Subjects who have received a total of 6 injections in Nabi-4514 or Nabi-4515.

Exclusion Criteria:

• Anticipated inability to follow the study protocol through-out the study period.
• Known history of any condition or factor judged by the investigator to preclude participation in the study or which might hinder compliance or failure to sign informed consent.
• Subjects who intend to receive, or who are receiving an Investigational New Drug/Device during the study.

Subjects will be invited into this study following their participation in Nabi-4514 or Nabi-4515.