SARS-CoV-2 vaccination in solid-organ transplant recipients: What the clinician needs to know.

In response to the COVID-19 pandemic, SARS-CoV-2 vaccines have been developed at an unparalleled speed, with 14 SARS-CoV-2 vaccines currently authorized. Solid-organ transplant (SOT) recipients are at risk for developing a higher rate of COVID-19-related complications and therefore they are at priority for immunization against SARS-CoV-2. Preliminary data suggest that although SARS-CoV-2 vaccines are safe in SOT recipients (with similar rate of adverse events than in the general population), the antibody responses are decreased in this population. Risk factors for poor vaccine immunogenicity include older age, shorter time from transplantation, use of mycophenolate and belatacept, and worse allograft function. SOT recipients should continue to be advised to maintain hand hygiene, use of facemasks, and social distancing after SARS-CoV-2 vaccine. Vaccination of household contacts should be also prioritized. Although highly encouraged for research purposes, systematic assessment in clinical practice of humoral and cellular immune responses after SARS-CoV-2 vaccination is controversial, since correlation between immunological findings and clinical protection from severe COVID-19, and cutoffs for protection are currently unknown in SOT recipients. Alternative immunization schemes, including a booster dose, higher doses, and modulation of immunosuppression during vaccination, need to be assessed in the context of well-designed clinical trials.

Hydroxychloroquine plus azithromycin early treatment of mild COVID-19 in an outpatient setting: a randomized, double-blinded, placebo-controlled clinical trial evaluating viral clearance.

BACKGROUND: Hydroxychloroquine has shown potential to block viral replication of SARS-CoV-2 in some in vitro studies. This randomised, double-blinded, placebo controlled clinical trial evaluated the efficacy of hydroxychloroquine plus azithromycin (HCQ/AZT) in reducing viral loads in patients with early and mild SARS-CoV-2 infection. METHODS: A single-centre randomised placebo-controlled clinical trial was conducted with outpatients with early and mild SARS-CoV-2 infection. Inclusion criteria were: patients aged 18-65 years with symptoms suggestive of COVID-19 for < 5 days, no significant comorbidities, and positive nasopharyngeal/oropharyngeal swab screening tests (POCT-PCR). Randomised patients received either hydroxychloroquine for 7 days plus azithromycin for 5 days or placebo. The primary endpoint was viral clearance within a 9-day period. Secondary endpoints included viral load reduction, clinical evolution, hospitalization rates, chest computed tomography evolution, and adverse effects. RESULTS: From 107 potential trial participants, 84 were enrolled following predetermined criteria. Statistical analyses were performed on an intention-to-treat (N = 84) and per-protocol (PP) basis (N = 70). On the PP analysis, the treatment (N = 36) and placebo (N = 34) groups displayed similar demographic characteristics. At 95% CI, no statistically significant between-group differences were found in viral clearance rates within 9 days following enrolment (P = 0.26). CONCLUSIONS: This randomised, double-blinded, placebo-controlled clinical trial evaluating outpatients with early and mild COVID-19 showed that viral clearance rates within a 9-day period from enrolment did not change with HCQ/AZT treatment compared with placebo, although no major cardiovascular events were observed in participants without comorbidities. Secondary outcomes were also not significantly improved with HCQ/AZT treatment compared with placebo. These findings do not support use of HCQ/AZT in this setting.