You're one of the lucky ones, then. If you do feel normal after a couple weeks, you could probably stop using nicotine without the vaccine. Just get through those 2 weeks or so and you are home free. Why take the chance of the vaccine having some unintended consequences?
One company is working on treatments for a number of conditions such as asthma, diabetes, attention defict disorder, depression, and dementia based on nicotine. These treatments target nicotinic receptors. If you ever needed a treatment or a cure for one of the conditions that these new drugs can help, and your receptors have been disabled by the vaccine, then that particular treatment option might be off the table solely because you had taken the vaccine.
Targacept: Biopharmaceutical Company - Product Pipeline
I went though 6 months of hell, hanging on to the steering wheel with white knuckles repeating "concentrate, concentrate" every time I had to drive somewhere. My work was so mistake-ridden that my 10 pages a day of output was down to 1 page a day of usable writing. At first I couldn't work at all. I was curled up in a ball on the couch crying my eyes out and wondering what might be the least painful way of killing myself. I did seek help and antidepressant mediction worked on the depression. It did not, however, help my cognitive impairments at all.
Maybe for me it would have gone away after 12 months or 2-3 years. Maybe never. But I wasn't getting any younger and 6 months was all I was willing to throw away feeling incompetent and unable to enjoy many things I hold dear that require attention and concentration. I figured that if this is how I am going to feel the rest of my life, and (because I'm not inhaling smoke) I will live many more years than I would have lived, then...forget it. Just shoot me.