Tetanus Toxoid Injection Site
For tetanus toxoid vaccines, use the anterolateral thigh in children ≤2 years of age and the deltoid muscle in children ≥3 years and all adults.
Age-Specific Injection Sites
Infants and Young Children (≤2 years)
- The anterolateral aspect of the thigh is the preferred site for all tetanus-containing vaccines (DTaP, DT) in infants and children through age 2 years 1, 2, 3.
- The standard dose is 0.5 mL administered intramuscularly 1, 2.
- This site minimizes the risk of nerve injury and provides adequate muscle mass for vaccine absorption 3.
Children ≥3 Years
- The deltoid muscle becomes the preferred injection site starting at age 3 years 1, 2, 3.
- Continue using 0.5 mL intramuscular administration 1, 2.
- Research demonstrates that deltoid injection at 18 months and older results in significantly less severe pain (8.1% vs 30.5%) and decreased limping compared to thigh injection 4.
Adolescents and Adults (≥7 years)
- The deltoid muscle is the preferred and recommended site for Tdap and Td vaccines 2, 3, 5.
- Administer 0.5 mL intramuscularly 2, 3, 5.
- The FDA label explicitly states the deltoid is preferred and warns against gluteal injection or areas with major nerve trunks 5.
Technical Administration Guidelines
Needle Selection and Technique
- Use 22-25 gauge needles for all age groups 6.
- For adults: 1 to 1½ inches in length 6.
- For children: 7/8 to 1¼ inches based on muscle size 6.
- Administer at a 90-degree angle into the muscle 6.
Critical Safety Considerations
- Never inject into the gluteal area due to risk of sciatic nerve injury 5.
- Do not administer intravenously or subcutaneously 5.
- Intramuscular administration produces significantly fewer local reactions than subcutaneous injection, with less redness (p<0.001), swelling (p<0.001), and pain (p<0.05) 7.
Common Pitfalls to Avoid
Site Selection Errors
- Historical data shows that 13-16% of DPT injections were administered at incorrect sites (deltoid, gluteal, or ventrogluteal) in infants who should have received thigh injections 8.
- Avoid the temptation to use the deltoid in children <3 years despite smaller muscle mass making the thigh more appropriate 1, 3.
Multiple Vaccine Administration
- When administering multiple vaccines simultaneously, use separate syringes at different anatomic sites 3.
- Some experts recommend no more than two injections per muscle, separated by at least one inch 3.
Post-Vaccination Monitoring
- Observe patients for 15 minutes after vaccination, especially adolescents and young adults, due to syncope risk 1, 3, 6.
- Have epinephrine 1:1,000 immediately available for potential anaphylactic reactions 5.
Evidence-Based Rationale for Site Selection
The preference for thigh injection in younger children and deltoid in older children/adults is supported by both safety and reactogenicity data. For DTaP vaccines specifically, thigh injection in children 12-35 months reduces medically attended local reactions by 47% compared to arm injection (RR: 1.88,95% CI: 1.34-2.65) 9. However, this advantage diminishes in older children, making the deltoid appropriate once adequate muscle mass develops at age 3 years 1, 3, 9.