615 - Measles Antibody Concentrations in Blood Products are Highly Variable: The Blood Antibody Characterization (BACH) Study

Publication Number: 615.5913

Shannon C.. Walker, Vanderbilt University Medical Center, Nashville, TN, United States; Ryan Moore, Vanderbilt University School of Medicine, Nashville, TN, United States; Henry Domenico, Vanderbilt University Medical Center, Nashville, TN, United States; Sandra Yoder, Vanderbilt Univ Med Ctr, Nashville, TN, United States; Jennifer Andrews, Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, TN, United States; C. Buddy Creech, Vanderbilt University School of Medicine, Nashville, TN, United States

Background: For over three decades, the Centers for Disease Control and Prevention (CDC) has recommended delaying receipt of live-virus vaccines, including measles, mumps, and rubella (MMR) and varicella vaccines, following the receipt of blood products (Table 1). These recommendations are based on the concern that passively acquired neutralizing antibodies in transfused blood products will inhibit development of a sufficient immune response following vaccination and would compromise durable immunity development. However, given advances in blood product manufacturing, changes in measles seroepidemiology, and increased risk of exposure due to recent measles outbreaks, we sought to re-evaluate these recommendations based on measles antibody concentrations in blood products.

Objective: The goal of the BACH Study was to measure total serum IgG and measles-specific IgG levels in the following blood products: packed red blood cells (pRBCs), plasma, platelets, and cryoprecipitate.

Design/Methods: Samples were obtained from recently expired ( < 72 hours) platelets, plasma, and cryoprecipitate units that would otherwise have been discarded, as well as surplus segments from non-expired pRBC units. Aliquots were spun at 2000g for 10 minutes to pellet any cellular material. Supernatants were harvested and frozen at -80C until batch testing occurred. Both total IgG and measles antibody levels were assayed using a standard sandwich ELISA kit from AbCam (Cambridge). Data from the human IgG kit was analyzed with Prism using a 4PL model. The measles sandwich ELISA kit is semiquantitative and was analyzed per protocol (negative < 9, indeterminant 9-11, and positive >11).

Results: A total of 221 samples were evaluated (105 platelets, 65 plasma/cryoprecipitate, and 51 pRBCs). The median total IgG concentrations were highest in plasma/cryoprecipitate (20.7 mg/mL), followed by platelets (7.1 mg/mL), and lowest in pRBCs (2.7 mg/mL) and were not associated with measles seropositive status (Figure 1). Measles seropositivity was also highest in plasma/cryoprecipitate (60/65, 92.3%), followed by platelets (71/105, 67.6%), and pRBCs (23/51, 45.1%) (Figure 2).

Conclusion(s): Given the substantial variability in measles serostatus across blood products, we recommend considering a personalized approach to measles vaccination after transfusion. Screening for measles seropositivity after a shorter post-transfusion interval (e.g., 1 month) or vaccinating according to schedule and measuring subsequent vaccine responses may be a more effective strategy to prevent measles disease.

Summary of Current CDC Recommendations to Delay Measles Vaccination following Transfusion of Various Blood Product Components
Table adapted from Table 3-6, Recommended intervals between administration of antibody-containing products and measles- or varicella-containing vaccine, by product and indication for vaccination, ACIP recommendations for Timing and Spacing of Immunobiologics, https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/timing.html#t-05. Accessed Nov 1, 2024.

Total IgG and Measles Seropositivity among Blood Product Components
The figure demonstrates on the vertical axis the distribution of total IgG levels in mg/mL in packed red blood cells (pRBCs), platelets, and plasma/cryoprecipitate. The horizontal axis shows the seropostivity status of the blood products as negative ( <9) or positive (9 and up).

Measles Seropositivity by Blood Product Component
The figure demonstrates the number of samples that had positive measles IgG levels out of the total number of samples per blood product: plasma or cryoprecipitate (60/65), platelets (71/105), and packed red blood cells (23/51).