Measles FAQ

Measles spreads through contact with infected nasal or throat secretions (coughing or sneezing) or breathing the air contaminated by an infected person. The virus can remain active and contagious in the air and on surfaces for up to 2 hours after an infected person leaves an area.

Cough, runny nose, red, watery eyes (conjunctivitis) and rash can all be symptoms of measles when accompanied by fever. The first symptom is usually fever followed by a rash 3-5 days later. The rash typically begins on the face and neck and spreads downward to the arms, legs and body. Individuals are infectious 4 days before the rash starts and for 4 days afterwards.

Typically, 10-14 days from the day of exposure, but can range from 7-21 days. Individuals are infectious 4 days before the rash starts and for 4 days afterward.

There is no specific treatment for measles; medical care is supportive. 

Does vitamin A prevent measles? 

No. Only vaccination prevents measles infection. 

Does vitamin A treat measles?

No. it is recommended that under a doctor's supervision, children infected with measles be given vitamin A once a day for two days to reduce the severity of illness (as part of supportive care). But this is a small amount while in the medical setting, usually while hospitalized for measles

While possible, contracting measles after full vaccination is extremely rare. If it does occur, the illness is typically mild, and the risk of spreading disease is significantly reduced.

People who meet the following criteria are presumed to have immunity to measles: 

• Written documentation of adequate vaccination:
  • 1 or more doses of MMR vaccine administered on or after the first birthday for preschool-age children and adults not at high risk. 
  • 2 doses of MMR vaccine for school-age children and adults at high risk, including college students, healthcare workers and international travelers. 
• Laboratory evidence of immunity (e.g., positive Measles IgG). 
• Laboratory confirmation of previous measles infection. 
• Born before 1957 (does not apply to healthcare workers).

• Children: 2 doses of measles-containing vaccine, with the first dose at 12-15 months and the 2nd dose at 4-6 years of age. The 2nd dose may be given earlier, provided it is at least 28 days after the first dose.
• Teenagers and young adults attending post-high school educational institutions: If no presumptive evidence of immunity, two doses of MMR vaccine, separated by at least 28 days.
• Adults: If no presumptive evidence of immunity, one dose of MMR vaccine is recommended.

Healthcare workers and international travelers should receive two doses.

• Anyone who has had a severe, life-threatening allergic reaction after a previous dose of MMR or to any vaccine component should not receive the vaccine.
• People who are severely immunocompromised, for example: 
  • People undergoing chemotherapy
  • People on immunosuppressive therapy
  • People on high-dose steroids
  • Those with health conditions like leukemia or AIDS (CD4 counts < 200)
• Women who are pregnant, or planning to become pregnant within the next month should not be vaccinated until after delivery. Women who are breastfeeding can be vaccinated.

The current MMR vaccine protecting against measles, mumps, and rubella was introduced in 1972. A single dose is 93% protective, and a two-dose series is 97% effective. This means that individuals who receive both doses reduce their risk of getting measles by 97% if exposed to measles.

Individuals vaccinated against measles between 1968-1989 likely received only a single dose of vaccine. While life-long immunity is expected to be present in ~99% of those who received two doses of vaccine, those who received a single dose should consider an additional dose of MMR vaccine if they belong to a high-risk group such as healthcare personnel, international travelers, and those in an area experiencing a measles outbreak.

Yes. Between 1963 and 1967, per CDC approximately <1 million individuals received an inactivated or "killed" measles vaccine, which was later found to be ineffective. This differs from the live attenuated or "weakened" measles vaccine which provides strong immunity. For people vaccinated between 1963 and 1967, it is recommended to check which vaccine you received. If uncertain or if you received the inactivated vaccine without a later measles vaccine, one dose of the MMR vaccine is recommended.

In general, those born before 1957 have presumptive immunity, as most were infected with measles, mumps, and rubella during their childhood before vaccines were available. However, this does not guarantee immunity for everyone. Healthcare workers born before 1957 without laboratory evidence of immunity (antibody titers) or documented measles infection should consider receiving two doses of the MMR vaccine.

For adults, no additional MMR doses are recommended if there is evidence of prior infection, birth before 1957, or documentation of two MMR doses. While antibody titers may decline over time, protection is still considered sufficient. If none of the above conditions are met and the titer is negative, at least one MMR dose (booster) is recommended. Additional doses may be required in outbreak settings, for healthcare workers, or prior to international travel.

Yes, measles antibody titers are not generally recommended. The MMR vaccine should be covered by major insurance carriers, regardless of whether titers were performed.

No, routine antibody testing to confirm measles immunity is not generally recommended. The need for a booster dose in adults depends on factors such as birth year, vaccination history, and medical conditions (e.g., weak immune system, pregnancy)

To be considered fully vaccinated, you should receive one additional dose of MMR vaccine. However, since the vaccine is live attenuated (containing a weakened but active virus), it may be contraindicated in certain situations, such as immunocompromised conditions, pregnancy, or a history of severe allergic reactions. Consult your healthcare provider for guidance.

A booster shot is unnecessary for those individuals fully vaccinated with two doses of the MMR vaccine. The vaccine provides lifelong protection in most cases. Even in the setting of an outbreak an additional dose is not recommended.

People born before 1957 lived through multiple measles epidemics before the first vaccine became available. As a result, these people are very likely to have had the measles disease. Thus, 95–98% of those born before 1957 are immune to measles. Note: Healthcare workers are an exception to this rule and must provide documented proof of immunity.