ESPN 54th Annual Meeting

ESPN 2022


 
Immmunologic response to BNT162b2 Covid-19 mRNA vaccine in adolescent kidney transplant recipients. A single center experience
VARVARA ASKITI 1 EVANGELIA GOLE 1 MARIA PAPADIMITRIOU 2 MARIA EIRINI GOURTZELIDOU 3 MINOS MATSAS 2 ANDROMACHI MITSIONI 1

1- 1. PEDIATRIC NEPHROLOGY DEPARTMENT, CHILDREN’S HOSPITAL “P&A KYRIAKOU” , ATHENS, GREECE
2- 2. DEPARTMENT OF MICROBIOLOGY, CHILDREN’S HOSPITAL “P&A KYRIAKOU”, ATHENS , GREECE
3- 3. NATIONAL AND KAPODISTRIAN UNIVERSITY OF ATHENS, MEDICAL SCHOOL, ATHENS, GREECE
 
Introduction:

 Early reports suggest low immunogenicity of SARS-CoV-2 vaccines in adult kidney transplant recipients (KTR). We describe the immunogenicity and safety profile of BNT162b2 mRNA Covid-19 vaccine in adolescents KTR and we compare it with the serologic response of natural infection. 

Material and methods:

 11 KTR (group A) received two doses of the vaccine between July 2021 and November 2021, while 4 KTR had a PCR-confirmed Covid-19 infection (group B). Serum samples were tested at 20 days and 3 months post the second dose for detection of IgG antibodies against spike protein of SARS-CoV-2, using chemiluminescent microparticle immunoassay (Architect/Alinity,Abbott). IgG results ≥50 AU/ml were considered positive.

Results:

 Median age was 14,5 years old (IQR 13-17), median time from transplant 16,26 months (IQR 10-58,6).  Positive serologic responses were observed in 7/11 (64%) of the vaccinated KTR and 4/4 (100%) of the naturally infected KTR. Three of the four seronegative patients had previously received rituximab (19, 18 and 8 months before vaccination respectively) compared to none of the responders, p=0.024.  Antibody titers were 10 times higher in the naturally infected group than vaccinated group [median 122 AU/ml (IQR 20-678) versus 1339 AU/ml (IQR 1234-1384)], p=0.001 Man-Whitney test]. In vaccinated KTR antibody levels increased from a median level of 11.6 AU/ml at 20 days to 122 AU/ml at 3 months post second dose. The vaccine was well tolerated with no rejection episodes.  No patient developed COVID 19 infection post vaccination, including the seronegatives, during the follow up period.

Conclusions:

 SARS-CoV-2 vaccination is safe in adolescents KTRs. Our cohort seem to have better immunologic response  than the previously reported in adults but longer time is required to mount an adequate antibody response compared to the general population. Vaccination results in lower antibody titers than natural infection. Rituximab has a negative effect on serologic response.