Abstract
Objectives: The immunogenicity of two-dose severe acute respiratory syndrome coronavirus 2 vaccine is lower among heart transplant (HTx) recipients, compared with the general population. Our aim was to assess the immunogenicity of a third-dose vaccine in HTx recipients.
Methods: This is a prospective cohort study of HTx recipients who received a third dose of the BNT162b2 vaccine. Immunogenicity was assessed by serum levels of anti-spike immunoglobulin G (S-IgG), taken at baseline and 14-28 days after the third dose. Titres above 50 U/ml were interpreted positive.
Results: We Included 42 HTx recipients at a median age of 65 years [interquartile range (IQR) 58-70]. At baseline, the median of 27 days (IQR 13-42) before the third dose and the median titre of the whole group was 18 U/ml (IQR 4-130). Only 14 patients (33%) were S-IgG seropositive. After the third dose, the proportion of seropositive patients increased significantly to 57% (P = 0.05) and the median titre increased significantly to 633 U/ml (IQR 7-6104, P < 0.0001). Younger age at HTx (OR per 1-year decrease 1.07, P = 0.05), low tacrolimus serum level (OR per 1-unit decrease 2.28, P = 0.02), mammalian target of rapamycin use (OR 13.3, P = 0.003), lack of oral steroids use (OR 4.17, P = 0.04) and lack of calcineurin inhibitor use (71% of responders vs 100% non-responders received calcineurin inhibitors, P = 0.01) were predictors of seropositive result after the third dose. However, no significant association was detected following adjustment for baseline S-IgG titre.
Conclusions: Third-dose booster of BNT162b2 vaccine significantly increased immunogenicity among HTx recipients who previously received a two-dose vaccine.
Keywords: BNT162b2 vaccine; COVID-19; Heart transplantation; Severe acute respiratory syndrome coronavirus 2; Third dose.
【저자키워드】 COVID-19, severe acute respiratory syndrome coronavirus 2, BNT162b2 vaccine, third dose., Heart transplantation, 【초록키워드】 Vaccine, coronavirus, immunogenicity, prospective cohort study, inhibitors, BNT162b2, Rapamycin, Immunoglobulin, heart, Patient, age, General population, predictor, Responder, inhibitor, seropositive, booster, Anti-spike, association, dose, acute respiratory syndrome, Serum level, recipients, median age, titre, U/mL, positive, recipient, mammalian, non-responder, decrease, significantly increased, lack, significantly, proportion, baseline, IQR, of BNT162b2, oral steroid, the median, 【제목키워드】 mRNA vaccine, dose, recipient, Improved, of BNT162b2,