How many days after receiving the Measles, Mumps, and Rubella (MMR) vaccine can I get another live vaccine?

Live Vaccine Spacing After MMR

If another live vaccine was not given on the same day as MMR, you must wait at least 28 days (4 weeks) before administering the next live vaccine. 1, 2, 3

Core Recommendation

• Parenterally administered live vaccines not given simultaneously must be separated by at least 4 weeks (28 days) to avoid immune interference. 1
• The FDA-approved MMR vaccine label explicitly states that if MMR is not given concurrently with other live viral vaccines, it should be given one month before or one month after administration of other live viral vaccines. 3
• This 28-day minimum interval applies to all parenteral live vaccines including varicella, yellow fever, and live attenuated influenza vaccine (LAIV). 1, 2

Why This Matters

• Administering a second live vaccine less than 28 days after MMR (unless given the same day) results in an invalid dose that must be repeated. 1, 2
• The immune response to one live-virus vaccine can be impaired if administered within 30 days of another live-virus vaccine, with documented evidence showing a 2.5-fold increased risk of vaccine failure when varicella was given <30 days after MMR. 1
• If you make this timing error, the second vaccine dose doesn't count and must be repeated at least 4 weeks after the invalid dose. 1

Same-Day Administration Exception

• The only way to avoid the 28-day wait is to give both live vaccines on the exact same day. 1, 2
• When MMR and varicella vaccines are administered simultaneously on the same day, immune responses are identical to vaccines given a month apart. 2
• The CDC emphasizes that simultaneous administration of all eligible vaccines is critical to ensure complete protection and reduce missed vaccination opportunities. 2

Specific Live Vaccine Exceptions

• Oral Ty21a typhoid vaccine can be given at any interval before or after MMR because it's administered orally rather than parenterally. 1
• Yellow fever vaccine can be administered at any time after single-antigen measles vaccine (though the standard 28-day rule applies to MMR combination vaccine). 1
• Inactivated vaccines can be given at any time before or after MMR without any waiting period required. 1

Common Pitfalls to Avoid

• Don't confuse the 28-day rule with the minimum interval between doses of the same vaccine (which is also 4 weeks for MMR series). 2, 4
• Don't assume a few days early is acceptable - even administering a live vaccine 1-27 days after MMR creates an invalid dose requiring revaccination. 1, 5
• Don't delay necessary vaccination unnecessarily - if the patient is present and eligible for multiple live vaccines, give them all on the same day rather than scheduling return visits. 2
• A study analyzing >1.6 million vaccination records found that live vaccine interval errors, while rare (0.5%), resulted in nearly one million dollars in revaccination costs when corrected. 5

Clinical Decision Algorithm

Is the patient receiving another live vaccine?

• YES → Are you giving it TODAY (same visit as MMR)?
  • YES → Administer both vaccines now 1, 2
  • NO → Schedule for ≥28 days from MMR date 1, 3
• NO (inactivated vaccine) → Give at any time, no waiting period needed 1

Documentation Requirements

• Record the exact date of MMR administration to calculate the earliest permissible date for the next live vaccine (28 days later). 2
• Only doses with written documentation of administration date should be considered valid. 2