Background: Solid-organ transplant (SOT) recipients are at a high risk of severe COVID-19, and are priority for vaccination. Here, we describe three cases of severe COVID-19 caused by SARS-CoV-2 B.1.1.7 lineage in vaccinated SOT recipients. Methods: Three SOT patients were hospitalized in the Policlinico Hospital of Bari (southern Italy) and underwent nasopharyngeal swabs for molecular detection of SARS-CoV-2 genes and spike protein mutations by real-time PCR. One sample was subjected to whole-genome sequencing. Results: One patient was a heart transplant recipient and two were kidney transplant recipients. All were hospitalized with severe COVID-19 between March and May 2021. Two patients were fully vaccinated and one had received only one dose of the BNT162b2 mRNA vaccine. All the patients showed a high viral load at diagnosis, and molecular typing revealed the presence of B.1.1.7 lineage SARS-CoV-2. In all three cases, prolonged viral shedding was reported. Conclusions: The three cases pose concern about the role of the B.1.1.7 lineage in severe COVID-19 and about the efficacy of COVID-19 vaccination in immunocompromised patients. Protecting immunocompromised patients from COVID-19 is a challenge. SOT recipients show a suboptimal response to standard vaccination, and thus, an additive booster or a combined vaccination strategy with mRNA, protein/subunit, and vector-based vaccines may be necessary. This population should continue to practice strict COVID-19 precautions post-vaccination, until new strategies for protection are available.
【저자키워드】 whole-genome sequencing, COVID-19 vaccine, SARS-COV-2 infection, B.1.1.7 lineage, solid-organ transplant recipients, 【초록키워드】 COVID-19, SARS-CoV-2, Efficacy, Vaccine, vaccination, Mutation, Hospitalized, severe COVID-19, Immunocompromised patients, Diagnosis, Italy, Spike protein, Immunocompromised patient, Nasopharyngeal swab, COVID-19 vaccination, Real-time PCR, Viral load, mRNA, Lineage, molecular, prolonged viral shedding, Precaution, booster, BNT162b2 mRNA vaccine, kidney transplant recipients, dose, Vaccination strategy, SOT, high risk, recipients, one patient, recipient, SARS-CoV-2 B.1.1.7, caused, reported, Two patient, All the patient, Protecting, SARS-CoV-2 gene, SOT patient, 【제목키워드】 COVID-19, SARS-CoV-2, Strategy, Transplant, B.1.1.7, New,