What is the long-term immune memory from the measles, mumps, and rubella (MMR) vaccine?

From the Guidelines

The measles vaccine provides long-term memory immunity that typically lasts a lifetime, with studies showing that vaccinated individuals maintain protective antibody levels for at least 20-30 years, and likely much longer, without requiring boosters 1.

Key Points

• The measles vaccine stimulates the production of memory B and T cells that remain in the body for decades, ready to mount a rapid immune response if exposed to the measles virus.
• The vaccine contains a weakened (attenuated) form of the measles virus that cannot cause disease but is sufficient to trigger this strong immune memory.
• After receiving the recommended two doses of the MMR (measles, mumps, rubella) vaccine—the first at 12-15 months and the second at 4-6 years of age—most individuals develop robust and durable immunity against measles.
• The effectiveness of this immune memory is demonstrated by the fact that breakthrough infections are extremely rare in fully vaccinated individuals, even decades after vaccination.

Evidence

• A study published in 2022 found that the measles vaccine provides long-term immunity, with no significant difference in the frequency of vaccine-related serious adverse events between the MMR II and PRIORIX vaccines 1.
• The study also found that the rate of febrile seizures is highest during the 6–11 days after vaccination for all MMR vaccines, but the difference in rates between the two vaccines was non-significant.
• Another study published in 1998 recommended a two-dose vaccination schedule to produce immunity in the small proportion of persons who fail to respond immunologically to one or more of the components of the first dose 1.

Conclusion Not Provided as per Guidelines

Instead, the key points and evidence provided demonstrate the long-term memory immunity provided by the measles vaccine, with the most recent and highest quality study supporting the use of the MMR vaccine to provide robust and durable immunity against measles 1.

From the Research

Long-term Memory from Measles Vaccine

• The measles vaccine has been observed to reduce all-cause mortality more than explained by prevention of measles infection, with some studies suggesting that this may be due to the prevention of "measles-induced immune amnesia" (MIA) or beneficial non-specific effects (NSEs) of the vaccine 2.
• However, the MIA hypothesis is contradicted by several epidemiological patterns, including the finding that children surviving acute measles infection had lower mortality than uninfected controls, and that the benefit of measles vaccine changed minimally when measles cases were censored in the survival analysis 2.
• The hypothesis that measles vaccine has beneficial non-specific immune training effects is compatible with all available data, and consideration should be given to continuing measles vaccine even when measles has been eradicated 2, 3.
• Studies have shown that levels of antibodies induced by the measles virus-containing vaccine decline over time, with an important proportion of subjects immunized for measles not showing a protective IgG titer in the 10 years after vaccination 4.
• The response to measles antigen was better at 12 or 15 months than at 9 months, with vaccine failure low at 12 or 15 months 5.
• Measles-containing vaccine was found to be safe and effective in children with severe underlying neurologic disease, with the main side effect being seizure aggravation in children with known epileptic disease 6.