Brief Answer:
Please refer to the following answer.
Detailed Answer:
Hi XXXX,
You are saying to have bacterial chest infection and you have the last dose of Verorab vaccine left.
In your case, the vaccine is done after the exposure. Usually, contraindications include fever. So, if you are feverish, you can postpone the last dose of vaccine for another day until you will be improved.
So, there is no need to start the course of vaccination, but to post-pone the last dose of vaccine.
After having the last dose, you might measure the levels of rabies antibodies. I'd also suggest to get tested for toxoplasma antibodies as usually, cat scratching are also related to toxo infection.
Wish you fast recovery!
Dr.Sonila