Can Quadracel (diphtheria, tetanus, and pertussis vaccine) and varicella (chickenpox vaccine) be administered together in a child?

Can Quadracel and Varicella Be Given Together?

Yes, Quadracel and varicella vaccine can and should be administered simultaneously at the same visit, using separate syringes at different anatomic sites. This approach is explicitly supported by FDA labeling and ACIP guidelines, with clinical trial data demonstrating equivalent immunogenicity and safety compared to separate administration 1.

Evidence from FDA-Approved Labeling

The Quadracel package insert directly addresses this question with clinical trial data:

• In the pivotal Study M5I02, children 4-6 years of age received Quadracel concomitantly with MMR and varicella vaccines, demonstrating non-inferior immune responses to all antigens 1
• The study included 263 subjects who received Quadracel alongside their second dose of MMR and varicella vaccines simultaneously 1
• Booster response rates for diphtheria (97.3%), tetanus (84.2%), and all pertussis antigens were comparable to separate administration 1
• Post-vaccination seroprotection rates reached 100% for diphtheria and tetanus when given with varicella vaccine 1

General Principles Supporting Simultaneous Administration

The ACIP has established that simultaneously administering all vaccines for which a child is eligible is critical for ensuring complete immunization at the appropriate age 2:

• Experimental evidence and extensive clinical experience demonstrate that simultaneous administration of live and inactivated vaccines produces seroconversion rates and adverse reaction rates similar to separate administration 2
• Approximately one-third of measles cases among unvaccinated preschool children could have been prevented if vaccines had been given simultaneously during prior visits 2
• Simultaneous administration is particularly important when uncertainty exists about whether the child will return for future doses 2

Specific Evidence for Varicella with DTaP-Containing Vaccines

Varicella vaccine has been studied extensively with DTaP vaccines (the pertussis component in Quadracel) and demonstrates excellent compatibility 2:

• Clinical trials involving 1,913 children aged 12-15 months showed that MMRV vaccine (which contains varicella) administered concomitantly with DTaP, Hib, and hepatitis B vaccines produced comparable seroconversion rates and antibody titers 2
• The immune response to MMR, varicella, and Hib vaccines administered concurrently with pneumococcal conjugate vaccine showed >90% seroconversion for all antigens 2
• Single-antigen varicella vaccine may be administered simultaneously with other vaccines recommended for children, including those containing diphtheria, tetanus, and pertussis antigens 2, 3

Practical Administration Guidelines

Use the following protocol for simultaneous administration 3, 4:

• Administer Quadracel intramuscularly (0.5 mL) in one site 1
• Administer varicella vaccine subcutaneously (0.5 mL) at a separate anatomic site using a different syringe 2, 3
• Never mix vaccines in the same syringe unless specifically FDA-approved for mixing 3, 5
• Document all vaccines in the child's permanent medical record 3, 5

Key Distinction: Inactivated vs. Live Vaccines

Understanding vaccine types clarifies why no spacing is required 2:

• Quadracel is an inactivated vaccine (contains inactivated poliovirus and toxoids) 1
• Inactivated vaccines can be administered simultaneously or at any time before or after live vaccines without interference 2
• The 4-week spacing rule only applies when two live parenteral vaccines are given separately (not simultaneously) 2
• Since Quadracel is inactivated, no spacing considerations apply with varicella vaccine 2

Safety Profile

The safety of simultaneous administration is well-established 1, 6, 7:

• In the Quadracel clinical trial, adverse events when given with MMR and varicella were comparable to separate administration 1
• Studies of combination MMRV vaccines with DTaP show similar or lower incidence of local and systemic adverse effects compared to component vaccines 8, 6
• Serious adverse events are not increased with simultaneous administration 4

Common Pitfalls to Avoid

Do not unnecessarily delay or separate these vaccines 3, 4:

• There is no medical benefit to spacing Quadracel and varicella apart 2
• Delaying vaccines increases the risk of missed opportunities and leaves children unprotected 2, 3
• Do not confuse the live-to-live vaccine spacing rule with inactivated-to-live administration—Quadracel requires no spacing from varicella 2, 4
• Ensure correct routes: Quadracel is intramuscular, varicella is subcutaneous 2, 1

Contraindications to Consider

Defer vaccination only for valid contraindications 3, 5:

• Moderate to severe acute illness 3, 5
• Immunodeficiency conditions (particularly relevant for varicella vaccine) 5
• Severe allergic reactions to vaccine components 3, 5
• Recent receipt of antibody-containing products (may affect varicella vaccine response) 5