Impaired Humoral Response in Renal Transplant Recipients to SARS-CoV-2 Vaccination with BNT162b2 (Pfizer-BioNTech)

Area of Science:

• Immunology
• Vaccinology
• Transplant Medicine

Background:

• Solid organ transplant (SOT) patients face high mortality (up to 20%) from SARS-CoV-2.
• SOT recipients often exhibit diminished immune responses to vaccinations.
• mRNA vaccines are crucial for SARS-CoV-2 prevention, necessitating evaluation in SOT patients.

Purpose of the Study:

• To assess the SARS-CoV-2 IgG antibody response in renal transplant recipients after two doses of the BNT162b2 mRNA vaccine.
• To compare the antibody response in renal transplant recipients to that of healthy healthcare workers (HCW).

Main Methods:

• SARS-CoV-2 IgG antibodies were detected using chemiluminescent immunoassay (CLIA).
• The study included 23 renal transplant recipients and 23 HCWs.
• Antibody levels were measured approximately 16 days after the second vaccine dose.

Main Results:

• Only 22% (5/23) of renal transplant recipients tested positive for SARS-CoV-2 IgG antibodies.
• In contrast, 100% (23/23) of HCWs showed a positive antibody response.
• The humoral immune response was significantly lower in transplant recipients compared to HCWs (p = 0.0001).

Conclusions:

• Two doses of the BNT162b2 mRNA vaccine elicit an impaired humoral immune response in renal transplant recipients.
• The antibody response in these patients is significantly lower than in healthy individuals.
• Personalized vaccination strategies may be necessary for immunocompromised transplant patients.