Can a patient receive the inactivated influenza (flu) vaccine and the measles‑mumps‑rubella (MMR) vaccine on the same day?

Can Flu and MMR Vaccines Be Given on the Same Day?

Yes, influenza vaccine and MMR vaccine can and should be administered on the same day at different anatomic sites. 1, 2

Evidence-Based Recommendation

The Advisory Committee on Immunization Practices (ACIP) explicitly recommends simultaneous administration of inactivated influenza vaccine with MMR vaccine, as this approach produces equivalent seroconversion rates and adverse event profiles compared to separate administration. 1, 2 This is a strong recommendation supported by decades of guideline consensus.

Key Administration Principles

Inactivated vaccines (like flu) can be given with live vaccines (like MMR) at any time:

• Inactivated influenza vaccines may be administered concurrently or sequentially with live vaccines such as MMR without interference. 1
• All inactivated vaccines can be given together at any time, before, or after other inactivated or live vaccines without concern for immunologic interference. 2

Proper technique is essential:

• Administer each vaccine at a separate anatomic site (different injection locations, preferably different limbs). 2, 3
• Never mix vaccines in the same syringe unless specifically FDA-licensed for mixing. 2, 3

Clinical Benefits of Same-Day Administration

Simultaneous vaccination prevents missed opportunities:

• Approximately one-third of measles cases among unvaccinated but vaccine-eligible preschool children could have been prevented if MMR had been administered at the same visit when another vaccine was given. 1
• Same-day administration is particularly critical when uncertainty exists that a person will return for future doses of vaccine. 1, 2

Immunogenicity is preserved:

• Simultaneously administering the most widely used live and inactivated vaccines produces seroconversion rates and rates of adverse reactions similar to those observed when vaccines are administered separately. 1
• Studies demonstrate that concurrent administration of influenza vaccine with MMR yields comparable immune responses (>93-100% seroconversion for all antigens) with no significant safety concerns. 2

Safety Profile

Adverse reactions are mild and comparable:

• Reassuring safety profiles have been noted for simultaneous administration of influenza vaccine with MMR and other vaccines. 1
• Although increased prevalence of injection site or systemic adverse reactions has been noted with concurrent administration in some studies, these symptoms have generally been reported to be mild or moderate. 1

Common Pitfalls to Avoid

Do not delay vaccination unnecessarily:

• Never defer any indicated vaccine to a separate visit; simultaneous administration prevents missed opportunities and can avert a substantial proportion of vaccine-preventable disease cases. 2
• Vaccination should not be delayed if a specific product is not available. 1

Do not use improper technique:

• Do not use the same anatomic site for multiple vaccines; always use separate injection sites. 2, 3
• Do not mix vaccines in the same syringe. 2, 3

Special Considerations for Children

For children aged 12-15 months receiving first doses:

• If using the combined MMRV vaccine (which includes varicella), discuss with parents that MMRV is associated with approximately one extra febrile seizure per 2,300-2,600 doses compared with separate MMR and varicella vaccines. 2
• This consideration does not apply when giving MMR alone with influenza vaccine. 2

For children aged 6-23 months:

• Co-administration of influenza vaccine with other vaccines (including MMR) was associated with increased risk for fever on the day of vaccination and the day following in some studies. 1
• Increased risk for febrile seizures has been noted within days 0-1 following co-administration of influenza vaccine with other vaccines during certain seasons, but most febrile seizures are brief and have a good prognosis. 1
• After considering risks and benefits, no changes in recommendations for administration of these vaccines were made, and these vaccines may be given concomitantly. 1

Clinical Bottom Line

Administer both influenza and MMR vaccines during the same visit at separate anatomic sites. 1, 2 This approach maximizes immunization completion rates, prevents missed opportunities, and produces equivalent immune responses compared to separate administration. 1, 2