Why can’t Prevnar 13 and Menactra be given together?
Understanding the clinical interaction between Pneumococcal Conjugate Vaccines (PCV13 / PCV20) and Menactra® (MenACWY-D).
The Core Conflict: Carrier Protein Interference
The restriction against administering PCV13 (Prevnar 13®) and Menactra® simultaneously stems from a phenomenon known as Carrier-Induced Epitopic Suppression. Both vaccines utilize structurally similar carrier proteins to stimulate an immune response. When given at the same time, they compete, leading to a blunted immune response specifically against the pneumococcal strains.
💉 PCV13 & PCV20
Pneumococcal Conjugate Vaccines
Carrier Protein:
CRM197
A non-toxic mutant of diphtheria toxin.
💉 Menactra®
Meningococcal (Groups A, C, Y, W-135) Vaccine
Carrier Protein:
Diphtheria Toxoid (D)
Inactivated diphtheria toxin.
Because CRM197 is a variant of the diphtheria toxin, the immune system prioritizes the heavy diphtheria toxoid load from Menactra, inadvertently suppressing the immune response to the pneumococcal polysaccharides attached to the CRM197 in the PCV vaccine.
Immunogenicity Impact: The Data
Clinical trials demonstrated that co-administration significantly reduces the Geometric Mean Concentrations (GMCs) of IgG antibodies for several pneumococcal serotypes compared to administering the vaccines separately. The chart below illustrates the blunted antibody response.
Illustrative data representing the relative drop in Geometric Mean Concentrations (GMC) of pneumococcal antibodies.
❔ Does this apply to PCV 20?
The short answer: Yes.
PCV20 (Prevnar 20®) utilizes the exact same carrier protein as PCV13: CRM197. It simply has 7 additional pneumococcal polysaccharide serotypes attached to it.
Because the mechanism of interference is based on the carrier protein (CRM197 vs. Diphtheria Toxoid), the same clinical guidelines that apply to PCV13 also apply to PCV15 and PCV20 when dealing with Menactra.
Clinical Guidelines & Administration Schedule
To prevent immune suppression and ensure maximum protection against both pneumococcal and meningococcal diseases, the CDC and ACIP mandate a specific spacing schedule if both vaccines are indicated for a patient.
Visit 1
Administer PCV
(PCV13, PCV15, or PCV20)
Visit 2
Administer Menactra
(MenACWY-D)
Note on other Meningococcal Vaccines: This specific 4-week separation rule applies primarily to Menactra (MenACWY-D) due to its Diphtheria Toxoid carrier. Other meningococcal conjugate vaccines like Menveo (MenACWY-CRM) or MenQuadfi (MenACWY-TT) utilize different carrier proteins and generally do not have this strict separation requirement with PCV, allowing for simultaneous administration if indicated.