Abstract
Background: The repeated waves of the COVID-19 pandemic have highlighted the necessity to optimize vaccine responses in immunocompromised populations. We investigated the safety and immunogenicity of a third, booster, dose of the Pfizer BNT162b2 vaccine in heart transplant (HT) patients.
Methods: The cohort comprised 96 adult HT patients who received a third homologous dose of the BNT162b2 vaccine 168 days after the second dose. The vaccine-induced antibody responses of both receptor-binding domain (RBD) IgG and neutralizing antibodies were assessed in all patients, with a positive antibody response being defined as the presence of either IgG anti-RBD or neutralizing antibodies. For a subset of patients, T cell response was also studied.
Results: The third dose was associated with a low rate of adverse events, mostly mild pain at the injection site. No serious adverse events were recorded, and there were no episodes of rejection. At 18 days following the third dose of the vaccine, the positive antibody response increased from 23% to 67%, with a corresponding increase in neutralizing capacity. The third dose elicited SARS-CoV-2 neutralization titers >9-fold and IgG anti-RBD antibodies >3-fold of the range achieved after the two primary doses. Mycophenolate use, lower eGFR and higher C-reactive protein were independently associated with a reduced likelihood of generating an immune response. Importantly, a specific T-cell response following the third dose was evident in the majority of transplant recipients.
Conclusions: An homologous third booster dose of the BNT162b2 vaccine gave overall consistent tolerability and a good safety profile, while eliciting humoral and cellular immune responses.
Keywords: BNT162b2 vaccine; COVID-19 pandemic; IgG anti-RBD; booster; heart transplantation; neutralizing antibodies.
【저자키워드】 BNT162b2 vaccine, Neutralizing antibodies, COVID-19 pandemic, Heart transplantation, booster, IgG anti-RBD, 【초록키워드】 COVID-19, neutralizing antibody, IgG, immune response, Neutralizing antibodies, C-reactive protein, BNT162b2, Pfizer, adverse events, Cohort, vaccine response, RBD, Patient, Pain, Immunocompromised, Mild, neutralizing capacity, homologous, booster dose, patients, T cell response, safety profile, SARS-CoV-2 neutralization, dose, anti-RBD, humoral, mycophenolate, Anti-RBD antibody, Serious Adverse Event, Tolerability, recipients, second dose, domain, injection, Specific T-cell response, cellular immune responses, rejection, positive antibody response, vaccine-induced antibody response, repeated, populations, likelihood, primary doses, defined, investigated, reduced, majority, increase in, the vaccine, elicited, subset, were recorded, were assessed, 【제목키워드】 immunogenicity, dose, clinical experience,