In contrast to immunocompetent participants in vaccine trials,^1,2 a low proportion (17%) of solid organ transplant recipients mounted a positive antibody response to the first dose of SARS-CoV-2 messenger RNA (mRNA) vaccines, with those receiving anti–metabolite maintenance immunosuppression less likely to respond.³ In this study, we assessed antibody response after the second dose.

Every year in the United States, approximately 6000 healthy adults accept the risks of donor nephrectomy to help family members, friends, or even strangers improve survival and quality of life.¹ It is imperative that the transplant community, in due diligence to donors, understands the risk of donation to the fullest extent possible and communicates known risks to those considering donation.^2,3 To date, studies have shown that perioperative death is extremely rare and subsequent survival rates are comparable with healthy nondonors.^4-6

With a significant organ shortage in the United States and with minimal expansions of the deceased donor pool in recent decades, many patients with end-stage renal disease are turning to live donor kidney transplantation to improve survival and quality of life.^1-5 Although many healthy adults are eager and willing to accept the risk of donor nephrectomy to help their loved ones, the responsibility lies within the medical community to quantify these risks as best as possible and to make this information available to those considering donation.

Immunocompromised individuals have been excluded from studies of SARS-CoV-2 messenger RNA (mRNA) vaccines. In such patients, the immune response to vaccination may be blunted. To better understand the immunogenicity of mRNA vaccines in immunocompromised individuals, we quantified the humoral response to the first dose in solid organ transplant recipients.

The field of organ transplantation benefits from large, comprehensive, transplant‐specific national data sets available to researchers. In addition to the widely used Organ Procurement and Transplantation Network (OPTN)‐based registries (the United Network for Organ Sharing and Scientific Registry of Transplant Recipients data sets) and United States Renal Data System (USRDS) data sets, there are other publicly available national data sets, not specific to transplantation, which have historically been underutilized in the field of transplantation. Of particular interest are the Nationwide Inpatient Sample and State Inpatient Databases, produced by the Agency for Healthcare Research and Quality. The USRDS database provides extensive data relevant to studies of kidney transplantation. Linkage of publicly available data sets to external data sources such as private claims or pharmacy data provides further resources for registry‐based research. Although these resources can transcend some limitations of OPTN‐based registry data, they come with their own limitations, which must be understood to avoid biased inference. This review discusses different registry‐based data sources available in the United States, as well as the proper design and conduct of registry‐based research.