A patient comes with a history of clean-cut injury which is not lacerated. He says that he received his last dose of tetanus vaccination about 10 years ago. What should be given next?

Explanation

## Correct Answer: D. Single dose tetanus toxoid This is a **clean, non-lacerated injury with a documented vaccination history of 10 years**—the discriminating facts. According to Indian guidelines (NTEP/IAP) and WHO recommendations, tetanus prophylaxis depends on two variables: wound type (clean vs contaminated/dirty) and vaccination status. A clean wound carries minimal tetanus risk; the patient's last dose was 10 years ago, which falls within the 10-year booster interval recommended in India. Since the wound is clean (not lacerated, not contaminated) and the patient has received tetanus toxoid within the last 10 years, a **single booster dose of tetanus toxoid** is sufficient to maintain immunity. This reactivates the anamnestic response without requiring the full primary series or immunoglobulin. The single dose acts as a booster, restoring protective antibody levels (≥0.1 IU/mL). Full vaccination is unnecessary because the patient already has prior immunity; immunoglobulin is reserved for dirty/tetanus-prone wounds in unvaccinated or inadequately vaccinated individuals. ## Why the other options are wrong **A. No vaccination needed** — This is wrong because even though the wound is clean, 10 years have passed since the last dose. Indian guidelines recommend booster doses every 10 years for adults with prior vaccination. Omitting a booster at the 10-year mark leaves the patient unprotected if another injury occurs within the next few years. The patient is at the threshold of losing protective immunity. **B. Full course of tetanus vaccination** — This is wrong because the patient has documented prior vaccination (10 years ago), indicating prior immunity. A full primary course (3 doses) is only indicated for **never-vaccinated or completely unvaccinated individuals**. Giving a full course to someone with prior immunity is wasteful and unnecessary; a single booster suffices to reactivate anamnestic immunity. **C. Tetanus toxoid + immunoglobulin** — This is wrong because immunoglobulin (TIG/HTIG) is reserved for **dirty, tetanus-prone wounds** (puncture wounds, crush injuries, burns, contaminated wounds) in unvaccinated or inadequately vaccinated patients. This wound is clean and non-lacerated; the patient has prior vaccination. Immunoglobulin is unnecessary and adds cost without benefit in this scenario. ## High-Yield Facts - **Clean wound + vaccination within 10 years** → single booster dose of tetanus toxoid only. - **Dirty/tetanus-prone wound + unvaccinated/inadequately vaccinated** → tetanus toxoid + TIG (250–500 IU IM). - **Booster interval for tetanus** in India is **10 years** for adults with prior primary vaccination. - **Protective antibody level** for tetanus is ≥**0.1 IU/mL**; booster restores this via anamnestic response. - **Full primary course** (3 doses) is given only to **never-vaccinated individuals**, not to those with prior immunity. ## Mnemonics **CLEAN wound decision tree** **C**lean wound + **L**ast dose <10 years = **E**ven **A**nti-toxin **N**ot needed (just observe). Clean wound + Last dose ≥10 years = Single booster. Dirty wound + Any vaccination status = Toxoid + Immunoglobulin. **TIG rule: Dirty wounds only** **T**etanus **I**mmunoglobulin is for **G**ross/dirty wounds. Clean wounds never get TIG, regardless of vaccination status. ## NBE Trap NBE pairs "10 years since last dose" with "clean wound" to trap students who either (1) think any injury always needs full vaccination, or (2) confuse the 10-year booster interval with a reason to give full course. The key discriminator is wound type: clean wounds are low-risk and only need a booster if due. ## Clinical Pearl In Indian primary health centres, the 10-year booster interval is often missed because patients don't maintain vaccination cards. Always ask "When was your last tetanus shot?" at every injury visit—if ≥10 years, give one dose immediately. This simple rule prevents unnecessary full courses and saves resources in resource-limited settings. _Reference: Park's Textbook of Preventive and Social Medicine (Tetanus prophylaxis table); IAP Guidelines on Immunization; WHO Guidelines on Tetanus Prophylaxis in Injury Prevention_