Are You Protected from Measles?

Young woman receives immunization

As measles outbreaks continue to occur in several states—the most in 25 years—patients have begun to ask me whether they are protected or whether they should receive another vaccination.

Public health officials are appropriately concerned. Up to 95% of persons who are exposed to the virus will become sick with measles if they have no immunity. Experts consider measles one of the most contagious of all infectious diseases. Health officials have traced several recent cases to Disney theme parks in Florida and California where international visitors from countries with low vaccination rates mix in crowded facilities. And this spring, California quarantined 900 students and faculty at two state universities to control a measles outbreak there.

Most of us, even physicians, have never seen a case a measles. That’s because, since 1968, one dose of the vaccine has been 93% effective in preventing the disease (97% effective if two doses are given). Since 2000, we have considered the U.S. entirely free of measles because no continuous outbreak has lasted more than a year (an outbreak traced from person to person within a community). Typically, an outbreak might begin when unvaccinated traveler brings the virus to the U.S., but its spread would fizzle out because most people were vaccinated. But growing numbers of persons who have not been vaccinated may bring our measles-free status to an end this year.

Measles is a serious disease. Before the U.S vaccination program, 3 to 4 million people got measles each year, nearly 50,000 were hospitalized, and several hundred died. Measles can cause deafness, and—although rare—the virus can remain in the brain where it may re-activate years later causing severe inflammation and swelling within the brain. The disease can also cause miscarriage, stillbirth, or other complications during pregnancy. I’d like to try now to answer the questions that many of my patients have brought to the office in the last few weeks.

Who is at high-risk for complications from measles?

Children under 5, adults over age 20, pregnant women, and individuals whose immune system is weakened are more likely to develop serious complications like pneumonia if they contract measles.

Who should be vaccinated against measles? Note: the MMR vaccination provides protection against measles, mumps, and rubella (also known as 3-day or German measles).

Most people should protect themselves against measles. The vaccine has a greater than 50-year history of safety and effectiveness.

  • Most adults who have no evidence of immunity should receive at least one dose of the measles vaccine.
  • Women of childbearing age, who are NOT PREGNANT and have no evidence of immunity, should receive at least one vaccination dose. You should not become pregnant for at least one month after being vaccinated. I recommend avoiding pregnancy for three months to provide an extra margin of safety.
  • Students at post-high school educational institutions, who have no evidence of immunity, should receive 2 doses of the measles vaccine. This is because measles spreads rapidly in college communities.
  • Teenagers and adults with no evidence of immunity should receive 2 vaccine doses before international travel.
  • Infants usually receive their first dose of this vaccine at 12 to 15 months of age. Parents should consult their pediatrician if they are planning international travel or if their unvaccinated child may have been in contact with measles.
  • Healthcare personnel with no evidence of immunity should receive 2 vaccine doses.
  • Persons exposed to mumps should ask their healthcare provider about whether to receive an additional measles vaccine dose.
  • If you are unable to locate your immunization records, you should get vaccinated. Receiving an extra dose is not harmful even if you already have immunity. As an alternative, we can do a blood test in the office to determine whether you already have immunity.
  • If your immunization record indicates you received an inactivated (killed) measles vaccine or a vaccine of unknown type, you should be re-vaccinated. The “killed” vaccine, given in 1963-1967, was not effective.

What is “evidence of immunity?”

An individual with evidence of immunity DOES NOT NEED THE MEASLES VACCINE. These persons are very unlikely to develop measles even if they come into contact with the virus because their body has developed immunity to the disease.  You have evidence of immunity if one or more of the following situations applies to you.

  • You were born before 1957. This does not guarantee immunity, but nearly everyone of that age was infected naturally and has immunity.
  • You have written documentation showing that you have been adequately vaccinated. We can review your immunization record to help you determine this.
  • A blood test shows you have immunity to measles. You have written confirmation of that lab result.

Who should NOT receive the measles vaccine?

The CDC website lists situations where an individual should not get the MMR vaccine or should wait until a later time. These include possible pregnancy, weakened immune system, and several others. Inform your healthcare provider if you belong to one of these groups.

Today we have no memory of the terror our grandparents and older generations felt when an infectious disease moved from family to family across a community taking young lives. Vaccines are a twentieth century miracle. They have been so effective that we no longer think about the possibility of such deadly outbreaks. But the organisms that cause these diseases have not vanished. Keeping them suppressed depends on maintaining high vaccination rates. I hope you will find this information helpful and share it with your loved ones and friends.

Judi Favor MD