Jim asked this question: "Do you need a new vaccination if you had measles as a child?"
In short: Most likely, no. If you were born before 1957, public health experts (including the CDC) consider you "presumptively immune" because the measles virus was so widespread during that time that virtually everyone was exposed and developed lifelong natural immunity.
However, there are a few specific nuances depending on your personal history and current lifestyle.
Natural Immunity: Before the vaccine was introduced in 1963, measles was so contagious that nearly 100% of children contracted it by age 15. Research shows that natural immunity from the disease is typically robust and lasts a lifetime.
The 1957 Cutoff: Because of the high prevalence of the disease, being born before 1957 is officially recognized as evidence of immunity in the United States.
Even if you had measles as a child, there are three scenarios where a doctor might recommend the MMR (Measles, Mumps, and Rubella) vaccine:
Healthcare Workers: If you work in a medical setting, your employer may require actual lab proof of immunity (a blood test called a "titer") regardless of your birth year. If the test is negative, you’ll likely need the vaccine.
International Travel: If you are traveling to an area with an active measles outbreak, some doctors suggest a booster just to be safe, especially if you aren't 100% certain of your childhood diagnosis.
Vaccination in the 1960s: If you were vaccinated between 1963 and 1967, you might have received an "inactivated" (killed) version of the vaccine that wasn't very effective. If you aren't sure you actually had the disease and only have records of a shot from those specific years, a modern MMR dose is recommended.
Yes. If you are already immune—either from the disease or a previous vaccine—getting another MMR shot is not harmful. The body’s immune system simply recognizes the vaccine and clears it.
Note: The MMR vaccine is a "live" vaccine, so it is generally not recommended for people who are severely immunocompromised or pregnant.