Which tetanus‑diphtheria‑acellular pertussis (Tdap) vaccine brand is considered the best for adult use in India?

Best Tdap Vaccine Brand for Adults in India

For adults in India, both Boostrix® (GlaxoSmithKline) and the indigenously developed SIIPL Tdap (Serum Institute of India) are equally effective and safe options, with SIIPL Tdap offering the advantage of local manufacturing and comparable immunogenicity to the international standard Boostrix®.

Evidence Supporting SIIPL Tdap as the Preferred Choice

Non-Inferiority to International Standard

• A 2023 Phase II/III trial in India demonstrated that SIIPL Tdap achieved booster responses to pertussis toxoid (94.3%), pertactin (92.6%), and filamentous hemagglutinin (95.0%), meeting non-inferiority criteria compared to Boostrix® 1
• The same study showed SIIPL Tdap achieved booster responses to tetanus toxoid (75.2%) and diphtheria toxoid (70.8%), with no significant differences from the comparator 1
• A parallel 2023 German study confirmed SIIPL Tdap's non-inferiority across all vaccine components, with seroprotection rates of 94.4% for diphtheria and 99.9% for tetanus 2

Superior Pertussis Antibody Response

• SIIPL Tdap produced higher geometric mean concentrations for anti-pertussis toxoid and anti-pertactin antibodies compared to Boostrix® in the German trial 2
• Booster response rates for pertussis antigens with SIIPL Tdap (93.8% for PT, 89.7% for FHA, 86.3% for PRN) were comparable or superior to Boostrix® 2

Safety Profile

• Both vaccines showed comparable frequencies of local and systemic adverse events, with no treatment-related serious adverse events reported for SIIPL Tdap 2, 1
• The safety profile was consistent across all age groups (4-65 years) in the Indian population 1

Alternative: Boostrix® Remains Excellent

Established Track Record

• Boostrix® has been used in more than 50 countries and has extensive post-marketing safety data 3
• Large US trials demonstrated that Boostrix® achieved seroprotection rates of ≥99.9% for tetanus and diphtheria in adolescents and adults 4
• The three-component acellular pertussis formulation in Boostrix® has proven efficacy in large-scale Phase III trials 3

Immunogenicity Across Age Groups

• Boostrix® induces seroprotective antibody levels in virtually all children and adolescents, and in high proportions of adults and elderly individuals 5
• Seropositivity rates for pertussis antigens are ≥90% across all age groups, including unvaccinated adolescents 5

Clinical Algorithm for Vaccine Selection in India

Step 1: Verify vaccine availability

• If SIIPL Tdap is available → use SIIPL Tdap (locally manufactured, non-inferior efficacy, potentially better cost-effectiveness) 2, 1
• If only Boostrix® is available → use Boostrix® (internationally validated, extensive safety data) 4, 5

Step 2: Confirm patient eligibility

• Both vaccines are indicated for adults aged 19-64 years who have not previously received Tdap 6
• Either vaccine can be administered regardless of interval since last Td dose 7

Step 3: Administration

• Single 0.5 mL intramuscular dose in the deltoid muscle 7
• Document manufacturer, lot number, and administration date 8

Important Caveats

Licensing Considerations

• The ACIP 2006 guidelines specified that only ADACEL® was licensed for adults in the US, while BOOSTRIX® was limited to ages 10-18 years 6
• However, current evidence shows Boostrix® is safe and effective in adults, and both SIIPL Tdap and Boostrix® are appropriately licensed for adult use in India 2, 1

Avoid Common Pitfalls

• Do not delay Tdap vaccination waiting for a specific brand—use whichever vaccine is immediately available to avoid missing the opportunity 7
• Do not administer tetanus boosters more frequently than every 10 years for routine immunization to prevent Arthus-type hypersensitivity reactions 7, 9
• Do not use pediatric DTaP formulations in adults—only Tdap products are appropriate 6

Special Populations Requiring Priority

• Healthcare workers with direct patient contact should receive Tdap as soon as feasible, with intervals as short as 2 years from last Td acceptable 6, 7
• Adults with close contact to infants <12 months should receive Tdap ideally at least 2 weeks before contact begins 6, 7