What are the current recommendations for Measles, Mumps, and Rubella (MMR) vaccine administration in response to a recent measles outbreak?

From the Guidelines

All individuals should receive two doses of the MMR (measles, mumps, rubella) vaccine according to the standard schedule: the first dose at 12-15 months of age and the second dose at 4-6 years of age, as recommended by the Advisory Committee on Immunization Practices (ACIP) in 2022 1. In light of recent outbreaks, unvaccinated individuals or those with uncertain vaccination status should get vaccinated immediately.

Key Recommendations

• For infants traveling to areas with measles outbreaks, the first dose can be given as early as 6 months of age, though this early dose doesn't count toward the routine two-dose series.
• Healthcare workers, college students, and international travelers should ensure they have documented evidence of immunity.
• During local outbreaks, public health authorities may recommend an additional dose for certain high-risk groups. The MMR vaccine is highly effective, with two doses providing about 97% protection against measles 1.

Importance of Vaccination

• Vaccination is crucial because measles is extremely contagious, spreading through airborne transmission, and can cause serious complications including pneumonia, encephalitis, and even death.
• The vaccine not only protects individuals but also contributes to community immunity, helping protect those who cannot be vaccinated due to age or medical conditions.

Vaccine Options

• Two MMR vaccines are available in the United States: M-M-R II (Merck and Co., Inc.) and PRIORIX (GlaxoSmithKline Biologicals), with PRIORIX being approved by the Food and Drug Administration in 2022 1.
• Both vaccines are fully interchangeable for all indications for which MMR vaccination is recommended 1. Some key points to consider when administering the MMR vaccine include:
• The vaccine can be administered to any person born before 1957 for whom the vaccine is not contraindicated 1.
• Adults who may be at increased risk for exposure to and transmission of measles, mumps, and rubella should receive special consideration for vaccination, including international travelers, persons attending colleges and other post-high school educational institutions, and persons who work at health-care facilities 1.

From the Research

Current Recommendations for MMR Vaccine Administration

In response to a recent measles outbreak, the current recommendations for Measles, Mumps, and Rubella (MMR) vaccine administration are as follows:

• The Advisory Committee on Immunization Practices (ACIP) recommends 2 doses of MMR vaccine routinely for children, with the first dose administered at age 12 through 15 months and the second dose administered at age 4 through 6 years before school entry 2.
• For adults at high risk for exposure and transmission, 2 doses of MMR vaccine are recommended, while 1 dose is recommended for other adults aged ≥18 years 2.
• The National Advisory Committee on Immunization (NACI) recommends that susceptible immunocompetent individuals six months of age and older, who are exposed to measles and have no contraindications, be given MMR vaccine within 72 hours of the exposure 3.
• For susceptible infants younger than six months of age, NACI recommends intramuscular immunoglobulin (IMIg) at a concentration of 0.5 mL/kg, to a maximum dose of 15 mL administered over multiple injection sites 3.

Post-Exposure Prophylaxis

For post-exposure prophylaxis, the following recommendations are made:

• The German Standing Committee on Vaccination (STIKO) recommends a single intravenous administration of immunoglobulins (400 mg/kg body weight) as soon as possible, preferably within six days, after exposure to measles, specifically for infants aged <6 months, susceptible pregnant women, and immunocompromised patients 4.
• NACI recommends that for susceptible contacts who are pregnant or immunocompromised, IMIg can be provided at a concentration of 0.5 mL/kg, or intravenous immunoglobulin (IVIg) can be provided at a dose of 400 mg/kg 3.
• A study on the effectiveness of measles vaccination and immune globulin post-exposure prophylaxis in an outbreak setting found that the effectiveness of MMR PEP was 83.4%, and the effectiveness of IG PEP was 100% 5.

Special Populations

For special populations, such as infants and immunocompromised individuals, the following recommendations are made:

• Infants born to women from highly vaccinated populations may become susceptible to measles before 6 months of age, and may be able to respond to vaccine between 6 and 9 months of age 6.
• The ACIP recommends that all persons aged ≥12 months with HIV infection who do not have evidence of current severe immunosuppression should receive 2 doses of MMR vaccine, with the first dose administered at age 12 through 15 months and the second dose administered at age 4 through 6 years 2.