The first dose of rabies vaccine is recommended to be administered within 24 hours. Because of this length of time, the vast majority of people will be able to reach the nearest vaccination unit and get their first rabies vaccination. It is possible, but not necessary, to rush to get the vaccination within 12 hours versus 24 hours. As long as the first injection is given within 24 hours, and the injections are given regularly in the future, the vast majority of people will be able to produce antibodies seven days after the first vaccination. Within seven days, the antibodies are basically blank for a period of time, so if you give the injection 1-2 hours or a few minutes earlier, the time of antibody production will not be significantly earlier, but will still be produced after a week, and some will be produced after two weeks.