Management of Individuals with No Measles Immunity Despite 3 MMR Doses

Core Principles

The Advisory Committee on Immunization Practices (ACIP) recommends that individuals with 2 documented doses of MMR vaccine are considered immune and do not need additional doses, even if serologic testing shows negative or equivocal results, and this principle extends to those who have received 3 doses 1
The Centers for Disease Control and Prevention (CDC) states that antibody titers can wane over time without loss of immune memory, meaning low or negative titers do not indicate susceptibility in properly vaccinated individuals 1

The American Academy of Pediatrics (AAP) advises against revaccination based solely on negative titers in someone with proper documentation of 3 MMR doses, and the individual should be managed as immune based on vaccination history alone 1
The CDC recommends that all healthcare personnel should observe airborne precautions when caring for measles patients, regardless of presumptive immunity status, due to the ~1% possibility of vaccine failure 2, 3
The CDC suggests using N95 respirators or equivalent respiratory protection when entering rooms of suspected or confirmed measles cases 3, 4
The CDC advises that healthcare personnel who develop measles should be excluded from work until ≥4 days following rash onset 2

The CDC states that MMR vaccine administered within 72 hours of exposure can prevent or modify disease, even in previously vaccinated individuals 5, 6
The CDC recommends that immune globulin (0.25 mL/kg intramuscularly) is an alternative for those who cannot receive MMR, though this is rarely needed in fully vaccinated individuals 5, 6
The CDC advises that observation should continue for 21 days after exposure (or 28 days if immune globulin was given) 5, 6

The ACIP indicates that a third dose of MMR is indicated specifically for mumps outbreak settings when public health authorities identify individuals at increased risk 7
The CDC notes that international travel to measles-endemic areas may warrant consideration of an additional dose, particularly if previous vaccination occurred decades ago 8