RESUMEN
BackgroundAttenuated immune responses to mRNA SARS-CoV-2 vaccines have been reported in solid organ transplant recipients. Most studies have assessed serological responses alone, and there is limited immunological data on vector-based vaccines in this population. This study compares the immunogenicity of BNT162b2 with ChAdOx1 in a cohort of kidney transplant patients, assessing both serological and cellular responses. Methods920 patients were screened for spike protein antibodies (anti-S) following 2 doses of either BNT162b2 (n=490) or ChAdOx1 (n=430). 106 patients underwent assessment with T-cell ELISpot assays. 65 health care workers were used as a control group. ResultsAnti-S was detected in 569 (61.8%) patients. Seroconversion rates in infection-naive patients who received BNT162b2 were higher compared with ChAdOx1, at 269/410 (65.6%) and 156/358 (43.6%) respectively, p<0.0001. Anti-S concentrations were higher following BNT162b, 58(7.1-722) BAU/ml, compared with ChAdOx1, 7.1(7.1-39) BAU/ml, p<0.0001. Calcineurin inhibitor monotherapy, vaccination occurring >1st year post-transplant and receiving BNT162b2 was associated with seroconversion. Only 28/106 (26.4%) of patients had detectable T-cell responses. There was no difference in detection between infection-naive patients who received BNT162b2, 7/40 (17.5%), versus ChAdOx1, 2/39 (5.1%), p=0.15. There was also no difference in patients with prior infection who received BNT162b2, 8/11 (72.7%), compared with ChAdOx1, 11/16 (68.8%), p=0.83. ConclusionsEnhanced humoral responses were seen with BNT162b2 compared with ChAdOx1 in kidney transplant patients. T-cell responses to both vaccines were markedly attenuated. Clinical efficacy data is still required but immunogenicity data suggests weakened responses to both vaccines in transplant patients, with ChAdOx1 less immunogenic compared with BNT162b2.
RESUMEN
BackgroundLimited data exists on the immunogenicity of vector-based SARS-CoV-2 vaccines in patients with kidney disease. Given their use in over 180 countries, such data is of upmost importance to inform policy on optimal vaccination strategies. This study compares the immunogenicity of BNT162b2 with ChAdOx1 in patients receiving haemodialysis. Methods1021 patients were screened for spike protein antibodies (anti-S) following 2 doses of either BNT162b2 (n=523) or ChAdOx1 (n=498). 191 patients underwent assessment with T-cell ELISpot assays. 65 health care workers were used as a control group. ResultsAnti-S was detected in 936 (91.2%) of patients post-vaccination. There was no difference in seroconversion rates between infection-naive patients who received BNT162b2, 248/281 (88.3%), compared with ChAdOx1, 227/272 (83.5%), p=0.11. Anti-S concentrations were higher following BNT162b, 462(152-1171) BAU/ml, compared with ChAdOx-1 79(20-213) BAU/ml, p<0.0001. Immunosuppression was associated with failure to seroconvert (p<0.0001); whilst being active on the transplant wait list was a predictor for seroconversion (p=0.02). Only 73 (38.2%) of patients had detectable T-cell responses post-vaccination, with no proportional difference between infection-naive patients who received BNT162b2, 2/19 (10.5%), versus ChAdOx1, 15/75 (20.0%), p=0.34. There were no quantitative differences in T-cell responses in infection-naive patients, with a median 2(0-16) SFU/106 PBMCs and 10(4-28) SFU/106 PBMCs in those receiving BNT162b2 and ChAdOx1 respectively, p=0.35. These responses were significantly weaker compared with healthy controls. ConclusionsEnhanced immunogenicity was seen with BNT162b2 compared with ChAdOx1, driven by superior humoral responses, with attenuated T-cell responses to both vaccines. Comparative data on clinical efficacy is now required. Significance StatementLimited data exist on the immunogenicity of vector-based SARS-CoV-2 vaccines in patients with kidney disease. Given their use in over 180 countries worldwide, such data are of upmost importance to inform policy on optimal vaccination strategies. This study compares the immunogenicity of BNT162b2 (n=523) against the adenovirus vector vaccine, ChAdOx1 (n=498), in 1021 haemodialysis patients. In infection-naive patients, overall seroconversion rates were comparable, however, spike protein antibody concentrations were significantly higher following BNT162b2. No difference in T-cell responses was seen, however, all naive patients had weaker responses compared with healthy controls. Equivalent attenuated cellular responses to both vaccines, with greater humoral responses to BNT162b2, suggests BNT162b2 has superior immunogenicity in this patient population, with data on clinical efficacy required.