Key Points
The approach to pretransplant coronavirus disease 2019 (COVID-19) vaccination mandates is heterogeneous across different countries and international transplant centers.
International and US transplant centers without vaccine mandates cited similar concerns with similar frequencies.
Increased public education to overcome vaccine hesitancy worldwide is needed to strengthen acceptance of recommended COVID-19 vaccination among transplant candidates.
Keywords: transplantation, COVID-19, international practices, patient safety, solid organ transplantation, vaccines, waitlist management
Visual Abstract
Abstract
Background
The coronavirus disease 2019 (COVID-19) pandemic created unprecedented challenges for solid organ transplant centers worldwide. We sought to assess an international perspective on COVID-19 vaccine mandates and rationales for or against mandate policies.
Methods
We administered an electronic survey to staff at transplant centers outside the United States (October 14, 2021–January 28, 2022) assessing the reasons cited by transplant centers for or against implementing a COVID-19 vaccine mandate. Each responding center was represented once in the analysis.
Results
Respondents (N=90) represented 27 countries on five continents. Half (51%) of responding transplant center representatives reported implementing a COVID-19 vaccine mandate, 38% did not, and 12% were unsure. Staff at centers implementing a vaccine mandate cited efficacy of pretransplant vaccination versus post-transplant vaccination, importance for public health, and minimizing exposure of other patients as rationale for the mandate. Of centers with a mandate, the majority (81%) of the centers mandate vaccination regardless of prior SARS-CoV-2 infection status and regardless of prevaccination spike-protein antibody titer or other markers of prior infection. Only 27% of centers with a vaccine mandate for transplant candidates also extended a vaccine requirement to living donor candidates. Centers not implementing a vaccine mandate cited concerns for undue pressure on transplant candidates, insufficient evidence to support vaccine mandates, equity, and legal considerations.
Conclusions
The approach to pretransplant COVID-19 vaccination mandate policies at international transplant centers is heterogeneous. International transplant centers with a vaccine mandate were more willing to extend vaccine requirements to candidates’ support persons, cohabitants, and living donors. Broader stakeholder engagement to overcome vaccine hesitancy across the world is needed to increase the acceptance of pretransplant COVID-19 vaccination to protect the health of transplant patients.
Introduction
The burden imposed on transplant programs by the coronavirus disease 2019 (COVID‐19) pandemic has been well documented, affecting waitlisting practices, donor acceptance, care delivery, as well as transplant center and organ procurement operations (1–9). Although available mRNA vaccines have proven highly effective in reducing the transmission and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants, the virus continues to spread, particularly among unvaccinated populations. Patients with end-stage organ failure may have a more robust response to vaccination before, rather than after, transplantation (10). To maximize efficacy, COVID-19 vaccines should be administered before transplantation (10). Nonetheless, vaccine hesitancy persists among some transplant candidates, and whether centers should mandate COVID-19 vaccination remains controversial.
Transplantation appears to be safe for vaccinated recipients from donors who have recovered from COVID-19 and have negative testing (11). A previous survey showed that compared with practices at US kidney transplant programs, transplant practitioners in other countries were less willing to accept organ offers for waitlisted candidates with incomplete COVID-19 vaccination status, and are more likely to delay scheduled living donor transplants for unvaccinated transplant candidates (7). Although transplant professional societies strongly recommend COVID-19 vaccination for transplant candidates (12–14), US transplant centers exhibit significant heterogeneity in COVID-19 vaccination mandate policies (15). While all US transplant programs encourage vaccination, most centers have not mandated COVID-19 vaccination for candidates and living donors, citing administrative opposition, legal prohibitions, and concern about equity in access to transplants (15,16). Using the same survey questions posed to US transplant centers, we conducted a survey of the presence, rationale, and scope of COVID-19 vaccine mandate policies at international solid organ transplant programs. Parallel to our US-based study (surveyed from October 14, 2021 to November 15, 2021) (15), we surveyed physicians, surgeons, coordinators, and other staff at solid organ transplant centers outside the United States.
Materials and Methods
Survey Design
The survey instrument comprised 23 questions addressing the reasons cited by centers for or against implementing a COVID-19 vaccine mandate as previously used in a recent parallel study of US centers (15). The survey instrument was developed by the study investigators and informed by a recent review of ethical concerns related to vaccine mandates (17). The survey queried information on the participants’ transplant center and the participants' role (physican by speciality, surgeon, clinical coordinator, administrator, social worker, or other) at the center. Vaccination policies for transplant candidates, caretakers, and cohabitants were asked. For centers without a mandate, reasons for not instituting a mandate were explored using nonexclusive, nonranked choices. For centers with a vaccine mandate, the scope of a mandate was explored across several hypothetical scenarios. Centers with and without a mandate for active candidates were also queried regarding vaccination requirements for potential living donors. This study was approved by the Saint Louis University Institutional Review Board (IRB protocol #32292). No participant concerns were raised in administration of the previous US and the present international surveys.
Survey Administration
The target population was staff at active international solid organ transplant centers, including surgeons, nephrologists, hepatologists, cardiologists, pulmonologists, infectious disease specialists, clinical coordinators, administrators, and social workers. Using the same survey tool, US results were collected first and reported separately (15). International participants were recruited from solid organ transplant centers in Africa, Asia, Europe, and North and South America (Table 1). Participants were solicited from the investigators’ professional connections, and the survey was emailed to respondents using Qualtrics Survey Software. The opportunity for self-elected participation through a Qualtrics link was also posted to professional society listservs after appropriate approvals, including that of The Transplantation Society, the European Society of Organ Transplantation, the Turkish Society of Nephrology, the Canadian Blood Services Living Donation Advisory Committee, and the Indian Society of Organ Transplantation. This report describes responses received between October 14, 2021, and January 28, 2022. The first page of the survey notes that the decision to proceed indicates consent to participate. Up to two reminders were provided for nonrespondents.
Table 1.
Survey participant characteristics
| Characteristic | International | United States (15) |
|---|---|---|
| Role in transplant center (n=89 a ) | ||
| Surgeon | 16 (14) | 36 (51) |
| Nephrologist | 70 (62) | 18 (26) |
| Hepatologist | 0 (0) | 4 (6) |
| Cardiologist | 1 (1) | 0.7 (1) |
| Pulmonologist | 1 (1) | 0.7 (1) |
| Infectious disease physician | 4 (4) | 12 (17) |
| Clinical coordinator | 2 (2) | 5 (7) |
| Administrator | 2 (2) | 11 (16) |
| Social worker | 0 (0) | 0.7 (1) |
| Other | 3 (3) | 11 (15) |
| Which solid organ transplants are performed at your center? (check all that apply) (n=90 a ) | ||
| Kidney | 96 (86) | 97 (136) |
| Pancreas | 28 (25) | 62 (88) |
| Liver | 37 (33) | 66 (93) |
| Heart | 22 (20) | 55 (78) |
| Lung | 14 (13) | 39 (55) |
| Geographical continent (n=90 a ) | ||
| Asia | 30 (27) | 0 (0) |
| Africa | 3 (3) | 0 (0) |
| Europe | 43 (39) | 0 (0) |
| North America | 19 (17) | 100 (141) |
| South America | 4 (4) | 0 (0) |
Data shown as % (n). US survey results provided for comparison, as previously published in Hippen et al. (15).
n is the item denominator for the international survey on the basis of the number of respondents.
Statistical Analyses
Each center was represented only once in the analysis. For centers with multiple respondents, we selected a single participant to represent the center using an a priori selection algorithm, as described in previous studies (6,7,15); similar to the US survey, for this survey the algorithm prioritized responses from transplant surgeons, followed by transplant physicians, and other providers. For centers with more than one response from a respondent in the same role at the same transplant center, after the above two steps, we retained the earliest submitted survey. Responses to each survey question were described using percentages and frequencies. To derive response rates, we divided the number of center responses by the total number of centers that responded to the question, such that percentages reflect proportions of respondents, as per previously described methods (5–7,15). For questions where participants were asked to “select all that apply,” the denominator for calculating percentages was the number of participants who submitted a response to the question. For the “select all that apply” questions, column total percentage may exceed 100% because each respondent was permitted to select more than one option. Free-text comments were assessed qualitatively and grouped into thematic categories by the investigators. All analyses were performed using SAS for Windows v14.0 (SAS Institute, Cary, NC).
Results
Respondents represented 27 countries on five continents. There were 107 total respondents, of whom 77% were from a center with only one survey respondent and 23% were from centers with more than one respondent. After applying the algorithm for identifying unique center responses, 90 center responses were assessed for primary analysis. Most of the study participants were nephrologists (70%), followed by surgeons (16%), infectious disease specialists (4%), coordinators (2%), administrators (2%), cardiologists (1%) and pulmonologists (1%), while three were other transplant professionals (Table 1).
Overall, 62% of the international respondent centers reported considering a COVID-19 vaccine mandate for any transplant candidates. Fifty-one percent of the international respondent centers reported instituting a COVID-19 vaccine mandate for all patients as a condition of active waitlisting (Table 2).
Table 2.
Consideration and reported implementation of COVID-19 vaccine mandates at international transplant centers
| Consideration and Implementation of Vaccine Mandate | International | United States (15) |
|---|---|---|
| Has your center considered a COVID-19 vaccine mandate for any candidates for any solid organ transplant? (n=87 a ) | ||
| Yes | 62 (54) | 88 (123) |
| No | 29 (25) | 9 (13) |
| Unsure | 9 (8) | 3 (4) |
| Has your center instituted a COVID-19 vaccine mandate for any candidates for any solid organ transplant? (n=84 a ) | ||
| Yes | 51 (43) | 36 (50) |
| No | 37 (31) | 61 (85) |
| Unsure | 12 (10) | 4 (5) |
Data shown as % (n). US survey results provided for comparison, as previously published in Hippen et al. (15). COVID-19, coronavirus disease 2019.
n is the item denominator for the international survey on the basis of the number of respondents, including conditional logic.
Centers with a Vaccine Mandate
Among those centers instituting a vaccine mandate policy, the most frequent justifications included efficacy of pretransplant COVID-19 vaccination compared with post transplant (67%), public health justification (63%), reducing transmission risks to other patients and family members (58%), reducing transmission risks to health care personnel (47%), and stewardship obligations to ensure organs are transplanted into patients at the lowest risk for SARS-CoV-2 infection (47%), (Figure 1A, Table 3). All respondent centers with a vaccine mandate policy in place reported that their policy included all actively listed solid organ transplant candidates. Among respondent centers with a mandate policy, the majority (97%) require vaccination regardless of prior SARS-CoV-2 infection status or evidence of prevaccination spike-protein antibody titers or other markers or prior infection. Eighty-two percent of international respondent centers permitted exemptions for demonstrated vaccine allergies, and 31% of centers permitted religious exemptions. Thirty-eight percent of international centers with a mandate reported they would decline patients registering a religious-based objection to vaccination for active candidacy, whereas 31% reported a case-by-case approach (Table 3). More than half of international centers (52%) with a vaccine mandate either exempted pediatric candidates or did not perform transplants in pediatric patients. Forty-two percent of the international centers with a vaccine mandate also require the candidate’s support person to be vaccinated against COVID-19. Finally, only 27% of all responding centers and 36% of centers with a vaccine mandate for transplant candidates extended a vaccine requirement to living donors (Table 4). Comparisons between survey responses from international centers and US centers (reported in Hippen et al. [15]) are shown in Tables 1–4.
Figure 1.
Comparison of reasons cited by international and US transplant centers (15) for implementing (A) and against implementing (B) a COVID-19 vaccine mandate.
Table 3.
Scope of mandate requirements at international transplant centers implementing a COVID-19 vaccine mandate
| Scope of Mandate Requirements | International | United States (15) |
|---|---|---|
| If your center has instituted a COVID-19 vaccine mandate for any solid organ transplant candidates, what is the rationale? (check all that apply) (n=43 a ) | ||
| Broad vaccine requirements for all patients are essential for public health reasons | 63 (27) | 52 (26) |
| Evidence that pretransplant COVID-19 vaccination is more effective than post-transplant vaccination, and protects patient safety | 67 (29) | 82 (41) |
| Stewardship obligations require that donated organs be transplanted into patients at the lowest risk for SARS-CoV-2 infection | 47 (20) | 64 (32) |
| Concern for minimizing risk to health care personnel, by reducing risk of SARS-CoV-2 exposure from unvaccinated candidates/recipients | 47 (20) | 40 (20) |
| Concern for minimizing risk to other patients and families, who may be exposed to unvaccinated transplant candidates and recipients in the health care setting | 58 (25) | 40 (20) |
| Concern for legal liability as a consequence of not implementing a vaccine mandate | 16 (7) | 4 (2) |
| Other | 9 (4) | 10 (5) |
| If your center has instituted a COVID-19 vaccine mandate and a candidate has demonstrated an immediate allergic reaction to the vaccine or one of its essential components, what is your center’s practice regarding candidacy? (n=33 a ) | ||
| Decline for active candidacy | 6 (2) | 10 (4) |
| Exempt from the vaccine mandate | 82 (27) | 62 (26) |
| Other | 12 (4) | 29 (12) |
| If your center has instituted a COVID-19 vaccine mandate and a candidate registers a religious objection to accepting the vaccine, what is your center’s practice regarding candidacy? (n=32 a ) | ||
| Decline for active candidacy | 38 (12) | 45 (19) |
| Exempt from the vaccine mandate | 31 (10) | 17 (7) |
| Other | 31 (10) | 38 (16) |
| Does your center’s COVID-19 vaccine mandate distinguish between type of solid organ transplant? (n=33 a ) | ||
| No—all actively listed solid organ transplant candidates at our center are subject to the vaccine mandate | 100 (33) | 58 (23) |
| Yes—only patients with non-life-threatening organ failure (e.g., renal failure requiring a kidney transplant) are subject to the vaccine mandate | 0 (0) | 20 (8) |
| Yes—only patients with life-threatening organ failure (e.g., decompensated cirrhosis, end stage heart failure, end stage lung disease) requiring a solid organ transplant are subject to the vaccine mandate | 0 (0) | 0 (0) |
| Yes—other | 0 (0) | 23 (9) |
| Does your center’s COVID-19 vaccine mandate distinguish between adult versus pediatric transplant candidates? (n=33 a ) | ||
| No—the vaccine mandate applies equally to adult and all pediatric candidates (defined as age <18 years) | 24 (8) | 10 (4) |
| No—the vaccine mandate applies to adult and pediatric candidates, but is limited to pediatric candidates for whom the COVID-19 vaccine is approved under emergency use authorization or full Food and Drug Administration approval | 24 (8) | 12 (5) |
| Yes—the vaccine mandate applies to adult candidates, but pediatric candidates (defined as age <18 years) are excluded from the mandate | 27 (9) | 27 (11) |
| N/A—our center only performs transplants in adult candidates | 21 (7) | 39 (16) |
| Other | 3 (1) | 12 (5) |
| If your center has instituted a COVID-19 vaccine mandate for (emergency use authorization-eligible) pediatric candidates, and the candidate’s parent and/or guardian refuses vaccination on behalf of the candidate, what is your center’s practice regarding candidacy? (n=31 a ) | ||
| Decline active candidacy for transplants in all circumstances | 13 (4) | 5 (2) |
| Waive the vaccine requirement in all circumstances | 13 (4) | 5 (2) |
| Decline active candidacy if end stage organ failure is life threatening (e.g., decompensated cirrhosis) | 3 (1) | 2 (1) |
| Decline active candidacy if end stage organ failure is not life threatening (e.g., kidney failure alone) | 10 (3) | 12 (5) |
| N/A—our center’s vaccine mandate does not include pediatric candidates, or our center does not transplant pediatric patients | 52 (16) | 66 (27) |
| Other | 10 (3) | 10 (4) |
| If your center has instituted a COVID-19 vaccine mandate for adult or pediatric candidates, does your center require evidence of “vaccine responsiveness” as a condition of active candidacy? (n=31 a ) | ||
| No—documentation of COVID-19 vaccination is sufficient | 97 (30) | 95 (39) |
| Yes—vaccinated candidates must demonstrate spike-protein IgG titers above a designated threshold or some other objectively defined measure of vaccine responsiveness | 3 (1) | 2 (1) |
| Other | 0 (0) | 2 (1) |
| If your center requires evidence of COVID-19 “vaccine responsiveness” as a condition of active candidacy, how does your center disposition a candidate who is “hyporesponsive”? (n=30 a ) | ||
| N/A—documentation of COVID-19 vaccination alone is sufficient | 83 (25) | 97 (38) |
| Require serial vaccine (booster) doses in hyporesponsive candidates until sufficient responsiveness thresholds are achieved | 10 (3) | 3 (1) |
| Other (please specify): | 7 (2) | 0 (0) |
| Does your center require solid organ transplant candidates to have a designated support person as a condition for receiving a transplant? (n=31 a ) | ||
| Yes | 52 (16) | 95 (38) |
| No | 39 (12) | 3 (1) |
| Unsure | 10 (3) | 3 (1) |
| If your center has instituted a COVID-19 vaccine mandate for adult or pediatric transplant candidates and also requires candidates to have a designated support person, does your center also require the candidate’s support person to be vaccinated against COVID-19? (n=31 a ) | ||
| Yes | 42 (13) | 10 (4) |
| No | 19 (6) | 75 (30) |
| N/A—our center does not require a support person | 39 (12) | 8 (3) |
| Other | 0 (0) | 8 (3) |
| If your center has instituted a COVID-19 vaccine mandate for adult or pediatric transplant candidates, and your candidate regularly cohabitates with others (family or otherwise), does your center also require that the candidate’s cohabitants be vaccinated against COVID-19? (n=30 a ) | ||
| Yes | 47 (14) | 5 (2) |
| No | 37 (11) | 90 (36) |
| Other | 17 (5) | 5 (2) |
| Does your center’s COVID-19 vaccine mandate distinguish candidates with a documented prior SARS-CoV-2 infection? (n=31 a ) | ||
| No—the vaccine mandate applies to candidates regardless of prior SARS-CoV-2 infection status and regardless of prevaccination spike-protein antibody titer or other markers or prior infection | 81 (25) | 95 (38) |
| Yes—the vaccine mandate is not required for candidates with documented prior SARS-CoV-2 infection | 3 (1) | 3 (1) |
| Yes—the vaccine mandate is not required for candidates with documented prior SARS-CoV-2 infection and evidence of a threshold spike-protein antibody titer or another marker of prior infection | 16 (5) | 3 (1) |
| Other | 0 (0) | 0 (0) |
Data shown as % (n). US survey results provided for comparison, as previously published in Hippen et al. (15). COVID-19, coronavirus disease 2019; SARS-CoV-2, severe acute respiratory syndrome coronavirus disease 2.
n is the item denominator for the international survey on the basis of the number of respondents, including conditional logic.
Table 4.
International transplant center policies regarding COVID-19 vaccine mandates for living donor candidates
| Policies for Living Donor Candidates Regarding Vaccine Mandates | International | United States (15) |
|---|---|---|
| Does your center require living kidney or liver donors to complete COVID-19 vaccination before donation surgery? (n=64 a ) | ||
| Yes—unvaccinated persons are not candidates for donation of either organ | 27 (17) | 14 (17) |
| Yes—unvaccinated persons are not candidates for liver donation but can donate a kidney | 0 (0) | 0 (0) |
| Yes—unvaccinated persons are not candidates for kidney donation but can donate a liver segment | 0 (0) | 2 (2) |
| No—our center recommends COVID-19 vaccination but has no requirement for living donors | 64 (41) | 78 (98) |
| Other | 9 (6) | 6 (8) |
Data shown as % (n). US survey results provided for comparison, as previously published in Hippen et al. (15). COVID-19, coronavirus disease 2019.
n is the item denominator for the international survey on the basis of the number of respondents, including conditional logic.
Centers without a Vaccine Mandate
More than one third (38%) of the respondent international centers reported that their center has not considered (29%) or were unsure of considering (9%) a COVID-19 vaccine mandate policy. Among all responding international centers, 37% had not instituted a policy, and 12% were unsure about mandating vaccination for all patients as a requirement for active transplant listing. The main reasons cited for not implementing a vaccine mandate were concerns for undue pressure on transplant candidates (29%), insufficient evidence to support a vaccine mandate (26%), concern for exacerbating inequities in access (26%), and legal considerations (26%), (Figure 1B). Free text responses to the survey questions from some international respondents identified specific concerns (Supplemental Table 1).
Discussion
Given the high morbidity and mortality rates among patients with end-stage organ failure and immunosuppressed solid organ transplant patients infected with SARS-CoV-2, the implementation of policies mandating COVID-19 vaccination for transplant candidates has been a subject of active debate. This study is, to our knowledge, the first comprehensive survey of the prevalence and scope of COVID-19 vaccine mandate policies at international transplant centers. On the basis of responses from October 2021 to January 2022, the majority (62%) of respondent international centers reported considering a vaccine mandate policy, and a slight majority of centers reported implementing a mandate policy (51%).
Despite a broad consensus on the safety and efficacy of COVID-19 vaccines to attenuate rates of SARS-CoV-2 primary infection, severe disease, the need for hospitalization, and mortality in both the general population and solid organ transplant candidates, our survey demonstrates that implementing a comprehensive COVID-19 vaccine mandate policy for all transplant candidates remains controversial. Concerns for coercion, exacerbating inequities in access to transplant, and legal concerns were the main justifications expressed by international respondents for not implementing a mandate. As was the case in our survey of US-based transplant centers (15), in our survey of international centers, none of the individual reasons against implementing a vaccine mandate were endorsed by a majority of respondents. International centers with a mandate policy cited the efficacy of COVID-19 vaccination before transplant in attenuating severe disease, public health justifications, the safety of other patients, family members and health care personnel, and stewardship obligations to ensure organs are transplanted into patients with the lowest risk for SARS-CoV-2 infection and associated adverse outcomes.
COVID-19 vaccine mandates remain a challenging and controversial area of public policy (17,18), illustrated by the wide range of extant public health policies used in different countries, ranging from opt-out vaccination approaches in public schools (19), incentives and certain penalties for nonvaccination (e.g., not allowing unvaccinated children in school, such as in some jurisdictions in United States; or withholding state benefits from families who do not vaccinate their children, such as in parts of Australia) (20–22) to legal and financial penalties for noncompliance with state-based vaccination requirements (23). Of necessity, decisions on whether to implement a vaccine mandate must be indexed to country specific health goals, scientific uncertainties, shifting risk profiles as the pandemic evolves, and underlying country-level resource limitations. To this extent, a universal approach to vaccine mandate policies for transplant candidates may be unfeasible, but this does not foreclose the possibility of tailoring policy according to the specific circumstances and priorities of individual countries. This first-of-its kind comprehensive survey illuminates the prevalence of vaccine mandate policies and the rationales cited for and against mandate policies among international transplant centers, allowing center leaders and local public health leaders to use this survey as a guide for their own national policy deliberations.
Despite strong recommendations from professional societies in the United States in favor of widespread vaccination of transplant candidates (12,13), our survey found a higher proportion of international centers implementing a vaccine mandate compared with US centers (15). Some key similarities between prevalent policies in international and US centers were also revealed by this study. In both cases, most centers with a vaccine mandate required vaccination, even with evidence of prior infection (81% for international centers; 95% for US centers), a finding is of interest, given a recent report on the durability of SARS-CoV-2 antinucleocapsid (N) protein antibodies among previously infected nonimmunosuppressed patients (24). A minority of centers with a mandate also required vaccination for living donors in roughly equal measure (27% for international centers; 42% for US centers). A minority of international and US programs extend their vaccine mandate to pediatric candidates, commensurate with a recent position paper counseling against vaccine mandates for pediatric candidates (25). Few international and US centers required additional serologic evidence of vaccine responsiveness. Key differences also emerged in the scope of vaccine mandate policies: 100% of international respondents with a mandate reported extension of the policy to all solid organ transplant candidates, whereas only 58% of US centers did so, with the remainder reporting more specific policy nuances, such as a limitation only to patients with non-life-threatening organ failure (20%). A requirement for a designated support person as a condition for candidacy is less common at international compared to US transplant centers (52% international center versus 95% US centers). However, among centers requiring a designated suport person that have a vaccine mandate for candidates, a higher proportion of international centers extended the vaccine requirement to the transplant candidate’s support person (42% international centers versus 10% US centers) and cohabitants (47% international centers versus 5% US centers). Of particular interest, international centers trended toward greater willingness to provide dispensation for religious-based objections to vaccination compared with US centers.
A key strength of this study is that it is, to our knowledge, the first comprehensive survey of international transplant center practices regarding the prevalence and scope of COVID-19 vaccine mandate policies. As such, the results are relevant to referring clinicians, transplant providers, and policy makers globally. However, our study has limitations. Respondents were identified by online outreach to transplant professionals in a limited number of countries, and not all programs are represented. Survey participation may be impacted by selection bias of transplant professionals especially engaged or interested in vaccine policy discussions, and the respondents’ answers may not generally represent policies at nonrespondent international centers. Nephrologists were overrepresented as survey respondents. Individual responses and collective response trends to the survey could have varied during different stages of the pandemic. Our survey was not designed to distinguish between countries with sufficient or insufficient overall access to COVID-19 vaccines. Reduced access to vaccination generally may be a reason for more liberal approaches to vaccine mandates in some circumstances (26). These survey data reflect the opinions and experiences of the respondents at the time of survey completion, policies may have changed after the survey was completed, and they may continue to evolve over time. Survey responses were not rank ordered by importance. Finally, our survey tool did not engage the topic of booster dose policies, except indirectly when querying requirements for vaccine responsiveness.
In conclusion, the prevalence and scope of pretransplant COVID-19 vaccination mandate policies is heterogeneous across international transplant centers. Although international centers were collectively more amenable to implementing vaccine mandates compared with US centers, both international and US centers without mandates cited similar concerns at generally similar frequencies. International centers with a vaccine mandate were more willing to extend vaccine requirements to candidates’ support persons, cohabitants, and living donors compared with US centers. Broader stakeholder engagement to overcome vaccine hesitancy across the world is needed to increase the acceptance of pretransplant COVID-19 vaccination to protect the health of transplant candidates.
Disclosures
T. Alhamad reports consultancy for CareDx, Mallinckrodt, and Veloxis; research funding from Angion, CareDx, Europhines, and Natera; honoraria from CareDx, Sanofi, and Veloxis; an advisory or leadership role for CareDx, Europhines, and QSANT; and participation in a speakers’ bureau for CareDx, Sanofi, and Veloxis. S. Anwar reports research funding from Echonous Kosmos (funding research on POCUS-enabled assessment of hemodynamic circuit using handheld ultrasounds and loaning research group 10 devices). D. Axelrod reports consultancy for CareDx and Talaris; ownership interest in CareDx; honoraria from CareDx, Specialist Direct, and Talaris; and serving on the NKF policy committee. B.E. Hippen reports employment as the Senior Vice President for Transplant Medicine and Emerging Capabilities, Global Medical Office, Fresenius Medical Care; ownership interest in Interwell Health; and being a scientific advisory board member of eGenesis Bio (uncompensated). K.L. Lentine reports consultancy for CareDx; participation in a speakers’ bureau for Sanofi; volunteer service on the ASN COVID-19 Response Team; and volunteer service on the NKF Transplant Advisory Committee. M.A. Schnitzler reports consultancy for CareDx and honoraria from OPTUM. All remaining authors have nothing to disclose.
Funding
K.L. Lentine is supported by the Mid-America Transplant/Jane A. Beckman Endowed Chair in Transplantation and receives research support related to kidney transplantation and organ donation from the National Institutes of Health (R01DK120518).
Acknowledgments
The authors thank survey respondents, including members of The Transplantation Society, European Society of Organ Transplantation, Turkish Society of Nephrology, Canadian Society of Transplantation (CST), CST Kidney Transplant Group, Indian Society of Organ Transplantation, American Society of Transplantation (AST) Outstanding Questions in Transplantation, AST Kidney Pancreas Community of Practice, and AST Infectious Disease Community of Practice list servs. We also thank the AST Education Committee for review of the survey instrument.
Author Contributions
Y. Caliskan, B.E. Hippen, and K.L. Lentine were responsible for conceptualization, methodology, investigation, and supervision. Y. Caliskan, B.E. Hippen, K.L. Lentine, and K. Maher were responsible for project administration. K. Maher was responsible for data curation. Y. Caliskan, K.L. Lentine, K. Maher, and M.A. Schnitzler were responsible for data analysis Y. Caliskan, B.E. Hippen, and K.L. Lentine drafted the manuscript. S. Anwar, D.A. Axelrod, Y. Caliskan, B.E. Hippen, V. Kute, N.N. Lam, and K.L. Lentine reviewed and edited the manuscript.
Data Availability Statement
Data availability is limited to aggregate summaries as reported on the basis of Institutional Review Board requirements.
Supplemental Material
This article contains the following supplemental material online at http://kidney360.asnjournals.org/lookup/suppl/doi:10.34067/KID.0004062022/-/DCSupplemental.
Free text responses to individual survey questions when respondents chose “other.” (Answers lightly edited for clarity, punctuation, grammar.). Download Supplemental Table 1, PDF file, 158 KB (157.9KB, pdf) .
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Free text responses to individual survey questions when respondents chose “other.” (Answers lightly edited for clarity, punctuation, grammar.). Download Supplemental Table 1, PDF file, 158 KB (157.9KB, pdf) .
Data Availability Statement
Data availability is limited to aggregate summaries as reported on the basis of Institutional Review Board requirements.