Your question is a good one and the confusion is common. In the intradermal route the volume injected per site does not change - it is the same small intradermal volume (0.1 mL of reconstituted vaccine per site) whether it is a fresh full course or a booster in a previously vaccinated person. What changes is the number of sites and the number of visits: a full intradermal post-exposure course uses two sites on day 0 (one on each forearm) and further visits as per the schedule, whereas a previously vaccinated person taking a re-exposure booster is given a single site on day 0 and one on day 3 - so the total quantity is less, but the per-site quantity is identical. Rabies immunoglobulin is also not needed for a properly previously vaccinated person.
Next Steps
1) Get the booster given at an anti-rabies clinic where the intradermal technique is done routinely - a correct intradermal bleb matters more than the volume, and a wrongly deep injection wastes the dose. 2) Carry your old vaccination card so the doctor can confirm you completed a valid previous course; only then does the shorter re-exposure schedule apply. If the earlier course was incomplete or the record is not available, a full post-exposure course is safer. 3) Wash the fresh wound with soap and running water for 15 minutes and apply povidone-iodine before you reach the clinic - this step reduces risk substantially. 4) The category of the bite still needs to be assessed in person, especially for face, hand or deep wounds, and tetanus cover reviewed. 5) Complete the second visit on day 3 even if the animal appears healthy. If you would like me to go through your vaccination card and the exposure details, you can consult me online on Practo, or visit me at Synergy Multispeciality Hospital, Miraj.
Health Tips
Please do not self-administer or ask a chemist to give the intradermal dose, and never delay the day 0 dose while arranging the record. Seek care immediately for a bite on the face, head, neck or fingers, or a deep or bleeding wound.