No study was conducted to evaluate the rabies neutralizing antibody titers after RIG injection on day 7. The only study that has supported the delay of RIG administration was done in 1996 by our institute, of which RIG was given on day 5 with the original Thai Red Cross intradermal regimen (2-2-2-0-1-1).

Rabies immunoglobulin (RIG) should be administered as soon as possible after the initiation of post-exposure prophylaxis. RIG should not be given after day 7 following the first rabies vaccine dose, because circulating neutralizing antibody will have begun to appear. Nevertheless, no study was conducted to evaluate the rabies neutralizing antibody titers after RIG injection on day 7.

The only study that has supported the delay of RIG administration was done in 1996 by our institute, of which RIG was given on day 5 with the original Thai Red Cross intradermal regimen (2-2-2-0-1-1). The ongoing study would prove the validity of the recommendation and eliminate the controversies in clinical practice.

Inclusion Criteria:

• Age 18 - 60 years
• WHO category III rabies exposure
• Received rabies vaccination on day 0 and 3.

Exclusion Criteria:

• Received RIG
• Immunocompromised hosts or receiving immunosuppressive therapy
• Received blood or blood product within 3 months
• Received anti-malarial drugs