has been refreshed! Take a tour.

Issue 1174: March 26, 2015

Ask the Experts: CDC Experts Answer Your Questions

The questions and answers (Q&As) in this edition of IAC Express first appeared in the March 2015 issue of Needle Tips. These Q&As all relate to measles and/or MMR vaccination. (Note: Four Q&As were edited to remain timely.)

IAC extends thanks to our experts, medical officer Andrew T. Kroger, MD, MPH, and nurse educator Donna L. Weaver, RN, MN, both from the National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC).

Measles Disease

MMR Vaccine

Measles Disease
Q: What are the signs and symptoms healthcare providers should look for in diagnosing measles?

A: Healthcare providers should suspect measles in patients with a febrile rash illness and the clinically compatible symptoms of cough, coryza (runny nose), and/or conjunctivitis (red, watery eyes). A clinical case of measles is defined as an illness characterized by
  • a generalized rash lasting 3 or more days, and
  • a temperature of 101°F or higher (38.3°C or higher), and
  • cough, coryza, and/or conjunctivitis.
Koplik spots, a rash present on mucous membranes, are considered pathognomonic for measles. Koplik spots occur from 1–2 days before the measles rash appears to 1–2 days afterward. They appear as punctate blue-white spots on the bright red background of the buccal mucosa (inside lining of cheek).

Providers should be especially aware of the possibility of measles in people with fever and rash who have recently traveled abroad, who have had contact with international travelers, or who have visited or had contact with someone who has visited an area affected by a current measles outbreak.

Providers should immediately isolate and report suspected measles cases to their local health department and obtain specimens for measles testing, including viral specimens for confirma- tion and genotyping. Providers should also collect blood for serologic testing during the first clinical encounter with a person who has suspected or probable measles.

Back to top

Q: How long does it take to show signs of measles after being exposed?

There is an average of 10–12 days from exposure to a person infected with measles virus to the appearance of the first symptom, which is usually fever. The measles rash doesn’t usually appear until approximately 14 days after exposure, 2–4 days after the fever begins.

Back to top

MMR Vaccine
Q: Has ACIP made any new recommendations for use of MMR vaccine (Merck) because of the current multi-state outbreak of measles?

A: No. Existing recommendations for use of MMR are still applicable. The most current recommendations were published in June 2013 and are available at

Back to top

Q: What is the earliest age at which I can give MMR to an infant who will be traveling internationally?

A: ACIP recommends that children who travel or live abroad should be vaccinated at an earlier age than that recommended for children who reside in the United States. Before their departure from the United States, children age 6 through 11 months should receive 1 dose of MMR. The risk for measles exposure can be high in both developed and developing countries. Consequently, CDC encourages all international travelers to be up to date on their immunizations regardless of their travel destination and to keep a copy of their immunization records with them as they travel. For additional information on the worldwide measles situation, and on CDC’s measles vaccination information for travelers, go to

Back to top

Q: We have young adult patients in our practice at high risk for measles, including those going back to college or preparing for international travel, who don’t have a record of receiving MMR vaccine or having had measles disease. How should we manage these patients?

A: You have two options. You can test for immunity or you can just give 2 doses of MMR at least 4 weeks apart. There is no harm in giving MMR vaccine to a person who may already be immune to one or more of the vaccine viruses. If you or the patient opt for testing, and the tests indicate the patient is not immune to measles or mumps, give your patient 2 doses of MMR at least 4 weeks apart. If the test indicates the person is not immune to rubella only, give 1 dose of MMR. If any test results are indeterminate or equivocal, consider your patient nonimmune. ACIP does not recommend serologic testing after vaccination because commercial tests may not be sensitive enough to reliably detect vaccine-induced immunity.

Back to top

Q: We have measles cases in our community. How can I best protect the young children in my practice?

A: First of all, make sure all your patients are fully vaccinated according to the U.S. immunization schedule.

In certain circumstances, such as for international travel, MMR is recommended for infants age 6 through 11 months. During a measles outbreak situation, consult your local or state health department to find out if measles vaccination of infants as young as age 6 months is recommended in your area as a control measure. Do not count any dose of MMR vaccine as part of the 2-dose series if it is administered before a child’s first birthday. Instead, repeat the dose when the child is age 12 months.

In the case of a local outbreak, you also might consider vaccinating children age 12 months and older at the minimum age (12 months, instead of 12–15 months) and giving the second dose 4 weeks later (at the minimum interval) instead of waiting until age 4–6 years.

Finally, remember that infants too young for routine vaccination and people with medical conditions that contraindicate measles immunization depend on high MMR vaccination coverage among those around them. Urge all your patients and their family members to get vaccinated if they are not immune.

Back to top

Q: What are the contraindications and precautions for MMR vaccine?

A: Contraindications are the following:
  • History of a severe (anaphylactic) reaction to neomycin (or other vaccine component) or following previous dose of MMR
  • Pregnancy
  • Severe immunosuppression from either disease or therapy
Precautions are the following:
  • Receipt of an antibody-containing blood product in the previous 11 months
  • Moderate or severe acute illness with or without fever
  • History of thrombocytopenia or thrombocytopenic purpura
Important details about the contraindications and precautions for MMR vaccine are in the current MMR ACIP statement, available at

Back to top

Q: I have patients who remember receiving MMR vaccine but have no written record, or whose parents report the patient has been vaccinated. Should I accept this as evidence of vaccination?

A: No. Self-reported doses and history of vaccination provided by a parent or other caregiver are not considered to be valid. You should only accept a written, dated record as evidence of MMR vaccination.

Back to top

Q: If you can give the second dose of MMR as early as 28 days after the first dose, why do we routinely wait until kindergarten entry to give the second dose?

A: The second dose of MMR may be given as early as 4 weeks after the first dose, and be counted as a valid dose if both doses were given after the first birthday. The second dose is not a booster, but rather it is intended to produce immunity in the small number of people who fail to respond to the first dose. The risk of measles is higher in school-age children than those of preschool age, so it is important to receive the second dose by school entry. It is also convenient to give the second dose at this age, since the child will have an immunization visit for other school entry vaccines.

Back to top

Q: Can I give MMR to a breastfeeding mother?

A: Yes. Breastfeeding does not interfere with the response to MMR vaccine. Vaccination of a woman who is breastfeeding poses no risk to the infant being breastfed. Although it is believed that rubella vaccine virus, in rare instances, may be transmitted via breast milk, the infection in the infant is asymptomatic.

Back to top

Q: What is the recommended length of time a woman should wait after receiving MMR vaccine before becoming pregnant?

A: Although the MMR package insert recommends a 3-month deferral of pregnancy after MMR vaccination, ACIP recommends deferral of pregnancy for four weeks. For details on this issue see ACIP recommendations (MMWR 2013; 62[4]: 1–34) at

Back to top

Q: Can we give an MMR to a 15-month-old whose mother is pregnant?

A: Yes. Measles, mumps, and rubella vaccine viruses are not transmitted from the vaccinated person, so MMR vaccination of a household contact does not pose a risk to a pregnant household member.

Back to top

Q: What is the recommendation for MMR vaccine for healthcare personnel (HCP)?

A: ACIP recommends that all HCP born during or after 1957 have adequate presumptive evidence of immunity to measles, mumps, and rubella, defined as documentation of two doses of measles and mumps vaccine and at least one dose of rubella vaccine, laboratory evidence of immunity, or laboratory confirmation of disease. ACIP also recommends consideration of MMR vaccination of all unvaccinated HCP who were born before 1957 and who lack laboratory evidence of measles, mumps, and/or rubella immunity or laboratory confirmation of disease.

During an outbreak of measles or mumps, 2 doses of MMR separated by at least 4 weeks should be recommended for unvaccinated HCP, regardless of birth year, who lack laboratory evidence of measles or mumps immunity or laboratory confirmation of disease. During an outbreak of rubella, 1 dose of MMR should be recommended for unvaccinated personnel, regardless of birth year, who lack laboratory evidence of rubella immunity or laboratory confirmation of infection or disease.

Back to top

Q:Would you consider HCP with 2 documented doses of MMR vaccine to be immune even if their serology for 1 or more of the antigens comes back negative?

A: Yes. HCP with 2 documented doses of MMR vaccine are considered to be immune regardless of the results of a subsequent serologic test for measles, mumps, or rubella. Documented age- appropriate vaccination supersedes the results of subsequent serologic testing. HCP who do not have documentation of MMR vaccination and whose serologic test is interpreted as “indeterminate” or “equivocal” should be considered not immune and should receive 2 doses of MMR. ACIP does not recommend serologic testing after vaccination.

Back to top

Q: If a healthcare professional had a positive test for measles antibody more than 10 years ago, is it necessary to retest them now?

A: No. Once measles immunity is documented, there is no need for further vaccination or testing. “Once immune, always immune” is true for varicella, mumps, and rubella, as well as for measles, regardless of the results of subsequent testing. ACIP does not recommend repeat antibody testing once evidence of immunity (such as appropriate vaccination or IgG seropositivity) has been established.

Back to top

Q: Can I give MMR to a child whose sibling is receiving chemotherapy for leukemia?

Yes. MMR vaccine should be given to the healthy household contacts of immunosuppressed people.

Back to top

Q: Is there any evidence that MMR causes autism?

A: No. This issue has been studied extensively in recent years, including a thorough review by the Institute of Medicine (IOM), an impartial group of the world’s leading experts that advises Congress on science issues. After reviewing more than 200 studies in 2004 and more than 1,000 studies in 2011, the consensus report strongly stated that the evidence did not show a link between vaccines and autism. To access the IOM committee minutes, as well as the executive summaries and full reports, visit

In 2014, researchers from the RAND Corporation published an update to the 2011 IOM report. In a systematic review of the evidence published on vaccine safety to date, they found the evidence was strong that MMR vaccine is not associated with autism. For more information, see “Evidence Shows Vaccines Unrelated to Autism” at and “MMR Vaccine Does Not Cause Autism” at

Back to top

How to submit a question to Ask the Experts

IAC works with CDC to compile new Ask the Experts Q&As for our publications based on commonly asked questions. We also consider the need to provide information about new vaccines and recommendations. Most of the questions are thus a composite of several inquiries.

You can email your question about vaccines or immunization to IAC at

As we receive hundreds of emails each month, we cannot promise that we will print your specific question in our Ask the Experts feature. However, you will get an answer.

You can also email CDC's immunization experts directly at There is no charge for this service.

If you have a question about IAC materials or services, email

Please forward these Ask the Experts Q&As to your colleagues and ask them to subscribe to IAC Express.

Back to top

About IZ Express

IZ Express is supported in part by Grant No. 1NH23IP922654 from CDC’s National Center for Immunization and Respiratory Diseases. Its contents are solely the responsibility of and do not necessarily represent the official views of CDC.

IZ Express Disclaimer
ISSN 2771-8085

Editorial Information

  • Editor-in-Chief
    Kelly L. Moore, MD, MPH
  • Managing Editor
    John D. Grabenstein, RPh, PhD
  • Associate Editor
    Sharon G. Humiston, MD, MPH
  • Writer/Publication Coordinator
    Taryn Chapman, MS
    Courtnay Londo, MA
  • Style and Copy Editor
    Marian Deegan, JD
  • Web Edition Managers
    Arkady Shakhnovich
    Jermaine Royes
  • Contributing Writer
    Laurel H. Wood, MPA
  • Technical Reviewer
    Kayla Ohlde

This page was updated on .