Since you recently completed a series of rabies vaccinations and also received a tetanus vaccine, I would not rush into lip filler immediately afterward. There isn't a known dangerous drug interaction between these vaccines and hyaluronic acid filler. However, both rabies and tetanus vaccines can temporarily stimulate the immune system and cause inflammation, swelling, fever, or other systemic symptoms. Because dermal fillers can occasionally develop delayed inflammatory reactions after immune stimulation, a conservative approach is to allow the immune response to settle before having another elective injection. Expert recommendations for HA fillers have generally suggested waiting approximately 2–4 weeks after vaccination when possible. So, if you are feeling completely well and have finished your rabies vaccination series, I would generally wait at least 2 weeks, and preferably closer to 4 weeks, after your most recent vaccine before getting lip filler. The fact that your previous lip filler was placed 3 months ago does not by itself prevent you from having another treatment. The more important consideration is allowing your body to settle after the recent vaccinations. I would also postpone the filler if you currently have fever, significant swelling, an active infection, or you are otherwise feeling unwell. One additional point: because you received the rabies vaccines following an exposure or suspected exposure, I would prioritize completing the rabies treatment exactly as recommended by your treating medical team. The vaccination schedule should not be delayed because of a cosmetic procedure. In short, 2 weeks is a reasonable minimum interval, while 3–4 weeks would be the more conservative choice, assuming you are feeling well and your rabies treatment is complete.