Hello, It sounds like your brother had an anaphylactic reaction to the tetanus injection, anaphylaxis causes a massive release of chemicals (histamine, etc.) to be released into your blood stream, this can cause your airway to swell, your blood pressure to drop, skin rashes, nausea and vomiting. The treatment that he received is appropriate, and it should be noted that he needs to avoid any vaccination that has tetanus contained within it. These are Tdap, Td, and DTap - please tell him to avoid these going forward. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. David Girardi, Internal Medicine Specialist