QUESTION

With the recent outbreak of measles, I’m wondering whether I should get vaccinated again. I’m 63 years old.

ANSWER

The recent spate of measles cases has generated a great deal of concern because it is the worst outbreak in 25 years, with more than 800 reported cases confirmed in 23 states. As the illness continues to spread, many people are now questioning whether they need to be revaccinated.

The good news is that most adults are at low risk for measles. The overwhelming majority of recent measles cases have occurred in unvaccinated children in certain close-knit communities in such states as New York, California, Georgia and Michigan. Some adults in those communities also have contracted the illness. However, for people who were born in 1957 or earlier (a time frame identified by the Centers for Disease Control and Prevention), it is highly likely that they had measles as a child. Once you’ve had the disease, you are immune to getting it again.

Fortunately, few cases have spread into the larger general population even though measles is extremely contagious. Most unvaccinated people will become ill if they come in contact with someone who is infected. The measles virus can remain in the air for up to two hours after an infected person leaves the room. Measles can cause life-threatening pneumonia and brain inflammation.

That said, some adults are at higher risk for measles. Those who live in a community that is undergoing a measles outbreak are more likely to come in contact with the virus. Health-care workers, college students (who often live in close quarters in dormitories) and people who are planning international travel also are at increased risk. If you fall into any of these categories—and don’t remember whether you had measles as a child—check your immunization records to be sure that you have received two doses of the measles, mumps, rubella (MMR) vaccine.

If you are not sure whether you received two doses of the MMR vaccine or had measles as a child, there is no harm in getting vaccinated. But talk with your doctor first. The MMR vaccine is not recommended for adults who have a weakened immune system due to cancer or another disease, a bleeding disorder or who have recently received a blood transfusion. A blood test also can confirm whether you have immunity to measles. Pregnant women should not receive the MMR vaccine.

Note: Adults who were vaccinated before 1989 may have received only one MMR dose, so they may have only partial immunity (one shot is roughly 93% effective at preventing the measles, while two shots are about 97% effective).