Rubella Immunity and Titration Guidelines

Primary Purpose of Rubella Serologic Testing

Clinical diagnosis of rubella is unreliable and should never be used to assess immune status, as many rash illnesses mimic rubella and many rubella infections are subclinical, according to the Centers for Disease Control and Prevention 1, 2
The only reliable evidence of previous rubella infection or immunity is the presence of serum rubella IgG antibodies, as stated by the Centers for Disease Control and Prevention 1, 2
Any antibody level above the standard positive cutoff value of a licensed assay constitutes evidence of immunity, as recommended by the Centers for Disease Control and Prevention 1, 2, 3

All women of childbearing age should have rubella immunity routinely determined, regardless of birth year, due to the devastating consequences of congenital rubella syndrome, as recommended by the American College of Obstetricians and Gynecologists 4
Birth before 1957 does NOT provide acceptable evidence of rubella immunity for women who could become pregnant, as it only provides presumptive evidence, according to the Centers for Disease Control and Prevention 1, 2
Prenatal serologic screening should be performed routinely, and laboratories should retain specimens until delivery for potential retesting, as recommended by the Centers for Disease Control and Prevention 5, 3
A negative rubella IgG test indicates susceptibility and requires postpartum vaccination, as stated by the American Academy of Pediatrics 6

Enzyme immunoassays (EIA/ELISA) are now the most commonly used commercial assays, having supplanted the older hemagglutination-inhibition (HI) test, as recommended by the Centers for Disease Control and Prevention 1, 2
Laboratories that regularly perform antibody testing provide the most reliable results due to standardized reagents and procedures, according to the Centers for Disease Control and Prevention 1, 2

Women should be counseled to avoid pregnancy for 3-4 weeks after rubella vaccination, as recommended by the American College of Obstetricians and Gynecologists 4
Post-infection immunity appears lifelong, though antibody levels may decline over time without increased susceptibility to disease, as stated by the Centers for Disease Control and Prevention 1, 2

Immune globulin (IG) is NOT recommended for post-exposure prophylaxis in pregnant women, as it does not prevent infection or viremia and has not been proven effective in preventing congenital rubella syndrome, as stated by the American Academy of Pediatrics 6
Exposed pregnant women require close monitoring for symptoms and prompt IgM testing if symptoms develop, as recommended by the American College of Obstetricians and Gynecologists 6