Serologic response to a third dose of an mRNA-based SARS-CoV-2 vaccine in lung transplant recipients

Lung transplant recipients have an increased risk for severe coronavirus disease 2019 (COVID-19) due to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A third dose of a SARS-CoV-2 vaccine has been recommended for all solid organ transplant recipients, but data from lung transplant recipients specifically are scarce. In this study, the serologic response to a third dose of an mRNA-based SARS-CoV-2 vaccine was measured in 78 lung transplant recipients. Sixty-two percent (n = 48) had a serological response to vaccination, which was significantly higher than after the second vaccine dose (27 patients (35%); p = 0.0013). A positive serologic response was associated with having had COVID-19 (p = 0.01), and higher serum IgG level and complement mannose binding lectin pathway activity prior to vaccination (p = 0.04 and p = 0.03, respectively). Serologic response was not associated with the dose of mycophenolate mofetil or prednisone or other immune status parameters. Eleven patients (14%) developed COVID-19 after the second or third vaccine dose, but this did not associate with serologic response after the second vaccine dose (9% in patients who developed COVID-19 versus 39% in patients who did not develop COVID-19 (p = 0.09)), or with serologic response above cut-off values associated with clinical protection in previous studies. In conclusion, the response to mRNA-based SARS-CoV-2 vaccines in lung transplant recipients improves significantly after a third vaccine dose. Factors associated with a positive serologic response are having had COVID-19 prior to vaccination, and serum IgG and complement mannose binding lectin pathway activity prior to vaccination. Serologic response did not associate with clinical protection against COVID-19 in this study.     

Evaluation of the Correlation Between Responders and Non-Responders to the Second Coronavirus Disease Vaccination In Kidney Transplant Recipients: A Retrospective Single-Center Cohort Study

BackgroundThe immune response to COVID-19 vaccination in kidney transplant (KTx) recipients is significantly lower than that in healthy controls. We evaluated immune responses after the COVID-19 vaccine and their possible relationship with other cofactors in KTx recipients.MethodsThis retrospective single-center cohort study included 29 KTx recipients 2-8 weeks after receiving 2 doses of the Pfizer-BioNTech SARS-CoV-2 messenger RNA vaccine. Anti-SARS-CoV-2 spike (S) immunoglobulin (Ig)-G levels were evaluated to define cofactors influencing the immune response between the responder (anti-SARS-CoV-2 IgG level ≥0.8 U/mL) (n = 16) and nonresponder groups (anti-SARS-CoV-2 IgG level <0.8 U/mL) (n = 13). The kinetics of antibodies between 2 and 6 months after the second vaccination was also compared between the groups.ResultsKTx recipients with IgG levels ≥0.8 U/mL were younger (54 [interquartile range {IQR}, 46.5-61] years vs 65 [IQR, 55-71.5] years; P = .01), had been transplanted for a longer median time (1588 [IQR, 1382-4751] days vs 1034 [IQR, 548.5-1833] days; P = .02), and were more often treated with a lower mycophenolate mofetil dosage (765.6 ± 119.6 vs 1077 ± 76.9 mg; P = .04) than KTx recipients with IgG levels <0.8 U/mL. There was no significant difference in antibody titers between time periods after the second dose in the responder group. At the 6-month follow-up, a serologic response against the SARS-CoV-2 S was observed in 44.4% of KTx recipients in the nonresponder group.ConclusionsMore than 50% of KTx recipients developed a higher antibody response after the second dose of COVID-19 vaccination.     

Analysis of Acquisition of COVID-2019 Neutralizing Antibodies in Organ Transplant Recipients

BackgroundThis study confirmed the kinetics of antibodies acquired by SARS-CoV-2 vaccination in solid-organ transplant recipients and examined their association with the development of COVID-19 and immunosuppressive status in organ transplant recipients.MethodsWe measured COVID-19 neutralizing antibody titer in 21 organ transplant recipients vaccinated with the COVID-19 vaccine and 14 nontransplant recipients (control group) 3 times before and at 1 and 6 months after the third dose of vaccine. By confirming the kinetics of the acquired antibodies, we examined the relevance of the background characteristics of organ transplant recipients, such as the development of infectious diseases and immunosuppressive status.ResultsThe proportion of patients with neutralizing antibodies was significantly higher in the nontransplant group than in the transplant group. Neutralizing antibody titers were significantly lower in transplant recipients when they were compared before the third dose and 1 month later. In the transplant recipient group, 11 patients were positive, and 10 were negative for neutralizing antibodies. When the causal relationship between the neutralizing antibody titer and background was examined, a positive correlation was found between the antibody titer and the number of years since transplantation, and a negative correlation was found between the tacrolimus trough values, amount of mycophenolate mofetil or steroids taken internally, and antibody titer.ConclusionThis study suggests that the effectiveness of vaccination in transplant recipients is associated with the post-transplant period before vaccination and the dose of immunosuppressive agents.     

Heart Transplantation from COVID-19–Positive Donors: A Word of Caution

BackgroundDuring the COVID-19 pandemic, efforts to maintain solid-organ transplantation have continued, including the use of SARS-CoV-2–positive heart donors.MethodsWe present our institution's initial experience with SARS-CoV-2–positive heart donors. All donors met our institution's Transplant Center criteria, including a negative bronchoalveolar lavage polymerase chain reaction result. All but 1 patient received postexposure prophylaxis with anti-spike monoclonal antibody therapy, remdesivir, or both.ResultsA total of 6 patients received a heart transplant from a SARS-CoV-2–positive donor. One heart transplant was complicated by catastrophic secondary graft dysfunction requiring venoarterial extracorporeal membrane oxygenation and retransplant. The remaining 5 patients did well postoperatively and were discharged from the hospital. None of the patients had evidence of COVID-19 infection after surgery.ConclusionHeart transplants from SARS-CoV-2 polymerase chain reaction–positive donors are feasible and safe with adequate screening and postexposure prophylaxis.     

Liver transplantation from active COVID-19 donors: A lifesaving opportunity worth grasping?

COVID-19 pandemic dramatically impacted transplantation landscape. Scientific societies recommend against the use of donors with active SARS-CoV-2 infection. Italian Transplant Authority recommended to test recipients/donors for SARS-CoV-2-RNA immediately before liver transplant (LT) and, starting from November 2020, grafts from deceased donors with active SARS-CoV-2 infection were allowed to be considered for urgent-need transplant candidates with active/resolved COVID-19. We present the results of the first 10 LTs with active COVID-19 donors within an Italian multicenter series. Only two recipients had a positive molecular test at LT and one of them remained positive up to 21 days post-LT. None of the other eight recipients was found to be SARS-CoV-2 positive during follow-up. IgG against SARS-CoV-2 at LT were positive in 80% (8/10) of recipients, and 71% (5/7) showed neutralizing antibodies, expression of protective immunity related to recent COVID-19. In addition, testing for SARS-CoV-2 RNA on donors’ liver biopsy at transplantation was negative in 100% (9/9), suggesting a very low risk of transmission with LT. Immunosuppression regimen remained unchanged, according to standard protocol. Despite the small number of cases, these data suggest that transplanting livers from donors with active COVID-19 in informed candidates with SARS-CoV-2 immunity, might contribute to safely increase the donor pool.

     

Humoral Response to the Third Dose of Sars-Cov-2 Vaccine in Kidney Transplant Recipients

BackgroundMost solid organ transplant recipients did not develop an appreciable serologic response after 2 doses of the mRNA SARS-CoV-2 vaccine.MethodsWe analyzed the humoral response after a third dose of the BNT162b2 vaccine in 130 kidney transplant recipients, compared to 48 health care workers, and associated factors, including prevaccine cellular immune response, by evaluating intracellular cytokine production after stimulation of donor's peripheral blood mononuclear cells.ResultsAfter 2 doses, most of the controls (47 out of 48, 98%) and only 40% of kidney recipients (52 of 130) kidney recipients were seropositive (P < .001). Most seronegative recipients developed a serologic response after the booster (47 out 78, 60%), thus bringing the total number of seropositive recipients to 99 out of 130 (76%). After the third dose, there was a significant increase in antibodies titers in both groups. Decreased humoral response was significantly associated with an older age, lower lymphocyte count, and a lower level of antibodies before booster administration. CD4⁺TNFα⁺ and CD4⁺INFγ⁺ were correlated with mean increase in antibody titers.ConclusionsA third dose of the BNT162b2 mRNA vaccine in kidney recipients is safe and effectively results in increased IgG anti-S levels, including in individuals who were seronegative after 2 doses. Long-term studies of the length of the immune response and protection are required.     

Humoral response after SARS-CoV-2 mRNA vaccination in patients with prostate cancer using steroids

ObjectivesThe effect of concomitant steroid use on the antibody response to a SARS-CoV-2 vaccine in patients with prostate cancer (PC) remains unknown. We aimed to evaluate the rates of antispike immunoglobulin G (IgG) antibody response to the BNT162b2 mRNA vaccine in patients with PC using steroids.MethodsThis cross-sectional study conducted from June 21, 2021 to January 5, 2022 included 215 patients with PC who received the second dose of the BNT162b2 mRNA vaccine at least 7 days before the measurement of titers of IgG antibodies against the receptor-binding domain of SARS-CoV-2 spike (S) protein. We compared the rate of anti-SARS-CoV-2 S IgG ≥15 U/mL between patients with or without concomitant steroid use.ResultsOf 215, we identified 33 patients who had concomitant steroid use. Of these, 12 and 21 patients were metastatic castration-sensitive PC and castration-resistant PC (CRPC), respectively. Patients with concomitant steroid use had a significantly lower rate of antibody titer ≥15 U/mL than those without steroid use (82% vs. 95%, P = 0.021). Patients with CRPC with concomitant steroid use (n =21) also had a lower rate of antibody titer ≥15 U/mL (71%) than those without steroid use (93%, P = 0.051), although this was not statistically different. Increased number of systemic treatments administered after diagnosis of CRPC (3 lines or more) were significantly associated with antibody titers <15 U/mL (97% vs. 77%, P <0.001).ConclusionThe humoral response to the BNT162b2 mRNA vaccine was significantly lower in patients with concomitant steroid use. Anti-SARS-CoV-2 S antibody titers were affected by CRPC status, the accumulation of post-CRPC treatments, and steroid use.     

Weak antibody response to three doses of mRNA vaccine in kidney transplant recipients treated with belatacept

Poor responses to mRNA COVID-19 vaccine have been reported after 2 vaccine injections in kidney transplant recipients (KTRs) treated with belatacept. We analyzed the humoral response in belatacept-treated KTRs without a history of SARS-CoV-2 infection who received three injections of BNT162b2-mRNA COVID-19 vaccine. We also investigated vaccine immunogenicity in belatacept-treated KTRs with prior COVID-19 and characterized symptomatic COVID-19 infections after the vaccine in belatacept-treated KTRs. Among the 62 belatacept-treated KTRs (36 [58%] males), the median age (63.5 years IQR [51–72]), without COVID-19 history, only four patients (6.4%) developed anti-SARS-CoV-2 IgG with low antibody titers (median 209, IQR [20–409] AU/ml). 71% were treated with mycophenolic acid and 100% with steroids in association with belatacept. In contrast, in all the 5 KTRs with prior COVID-19 history, mRNA vaccine induced a strong antibody response with high antibody titers (median 10 769 AU/ml, IQR [6410–20 069]) after two injections. Seroprevalence after three-vaccine doses in 35 non-belatacept-treated KTRs was 37.1%. Twelve KTRs developed symptomatic COVID-19 after vaccination, including severe forms (50% of mortality). Breakthrough COVID-19 occurred in 5% of fully vaccinated patients. Administration of a third dose of BNT162b2 mRNA COVID-19 vaccine did not improve immunogenicity in KTRs treated with belatacept without prior COVID-19. Other strategies aiming to improve patient protection are needed.     

SARS-CoV-2 Infection After Vaccination: Kidney Transplant Recipient Profile and Disease Evolution in a Single Center

BackgroundSARS-CoV-2 infection has had a major impact on kidney transplant patients. Recent evidence suggests that solid organ transplant recipients who received mRNA vaccines reach low immunization rates. There are only few reports about the risk factors and severity of COVID-19 in these patients. Our single center experience describes the patient profile and disease evolution observed in this vulnerable group after inoculation.Material and MethodsRetrospective cohort study with kidney transplant patients who received a COVID-19 vaccine before testing positive for SARS-CoV-19 using polymerase chain reaction. Demographic characteristics and clinical information are described and compared with our previous series of patients who were infected before the initiation of the vaccination rollout.ResultsSixteen kidney transplant recipients diagnosed with COVID-19 after being vaccinated were included and compared with our previous series of 76 unvaccinated patients who were positive for COVID-19. No differences were found among risk factors such as age, time after transplant, hypertension, and obesity between groups (P value > .05). After COVID-19 diagnosis among inoculated patients, 10 patients were hospitalized, and 4 of who met the criteria for admission to the intensive care unit. Three patients died of COVID-19 complications. Despite this, the incidence of infections has decreased after vaccination rollout (P value < .05).ConclusionsPatients’ risk profiles remain constant among recipients who were positive for COVID-19 between waves. We did not find significant differences in hospitalization and severity rates in this reduced group of patients. However, the overall incidence in our kidney transplant population has decreased.     

Serologic Status According Severe Acute Respiratory Syndrome Coronavirus 2 in Patients After Orthotopic Heart Transplantation

BackgroundThe SARS-CoV-2 pandemic is ongoing. In this context, patients after organ transplantation are especially endangered because of their increased susceptibility to infections. Real effectiveness of vaccinations against SARS-CoV-2 and exposition to the virus in populations after organ transplantation is still being assessed.MethodsWe investigated 371 adult patients (82.7% men, 17.3% women), aged 54 ± 14 years, with a median time from transplantation of 1296 days (interquartile range, 473-400 days) after orthotopic heart transplantation consecutively admitted to the transplant center between February and September 2021. SARS-CoV-2 spike protein antibodies were assessed quantitatively by Elecsys Anti-SARS-CoV-2 S. Data according to past COVID-19 infection and vaccination were compared with the test results.Among the whole group, 59 patients were unvaccinated and had no past COVID-19 infection, 200 patients had a full course of vaccination (2 doses) with an mRNA vaccine, 1 patient had received a viral vector vaccine, 11 patients had had a single dose of an mRNA vaccine, and 99 patients had previously had a COVID-19 infection. Median time from vaccination to antibody assessment was 54 days (interquartile range, 30-76 days).AimThe aim of this study was to determine exposure to the virus among patients after heart transplantation before vaccination and humoral response to the vaccination and assess the role of antispike antibodies in the prevention of infection.ResultsAfter vaccination, 22.3% had no antibodies (45 patients), 47.3% had titers between 0.8 U/mL [0.82 binding antibody units (BAU)/mL] and 250 U/mL (257.25 BAU/mL; 95 patients), and 30.2% had titers above 250 U/mL (257.25 BAU/mL; 61 patients). After a single dose of vaccine, 63% patients had no antibodies. In the group of unvaccinated patients, 3 patients had titers above 250 U/mL (257.25 BAU/mL; 5.1%) and 12 patients had titers up to 250 U/mL (257.25 BAU/mL; 20.3%).In patients after COVID-19 infection, only 2% did not show antispike antibodies, and in 61.4% the titers were above 250 U/mL (257.25 BAU/mL).In the group of patients infected after the full course of vaccination (4 patients after a single dose and 2 after 2 doses), none of the patients developed antibodies after vaccination. Up to the end of September 2021, none of the patients with antibodies against SARS-CoV-2 developed COVID-19.ConclusionsThe presence of spike protein antibodies may be a relevant marker of effective vaccination. In patients after heart transplantation, exposure to SARS-CoV-2 is high.     

Efficacy and safety of a fourth dose of the COVID-19 vaccine in kidney transplant recipients: A systematic review and meta-analysis

BackgroundKidney transplant recipients (KTRs) who become infected with SARS-CoV-2 are at greater risk of serious illness and death than the general population. To date, the efficacy and safety of the fourth dose of the COVID-19 vaccine in KTRs have not been systematically discussed.MethodsThis systematic review and meta-analysis included articles from PubMed, Embase, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, and Wanfang Med Online published before May 15, 2022. Studies evaluating the efficacy and safety of a fourth dose of the COVID-19 vaccine in kidney transplant recipients were selected.ResultsNine studies were included in the meta-analysis, with a total of 727 KTRs. The overall pooled seropositivity rate after the fourth COVID-19 vaccine was 60% (95% CI, 49%–71%, I² = 87.83%, p > 0.01). The pooled proportion of KTRs seronegative after the third dose that transitioned to seropositivity after the fourth dose was 30% (95% CI, 15%–48%, I² = 94.98%, p < 0.01).ConclusionsThe fourth dose of the COVID-19 vaccine was well tolerated in KTRs with no serious adverse effects. Some KTRs showed a reduced response even after receiving the fourth vaccine dose. Overall, the fourth vaccine dose effectively improved seropositivity in KTRs, as recommended by the World Health Organization for the general population.     

Analysis of Risk Factors for a Low Immune Response to Messenger RNA COVID-19 Vaccine in Kidney Transplant Recipients and Differences Between Second and Third Dose

BackgroundThe efficacy of the response to SARS-CoV-2 vaccination in kidney transplant recipients is low. The aim of our study was to evaluate the risk factors correlated with the low antibody response and whether there was an improvement between the second and the third dose.MethodsA prospective study was conducted on 176 kidney transplant recipients who received the second and the third dose of the anti-SARS-CoV-2 mRNA Comirnaty vaccine. We evaluated the seroconversion process after administration of the second and the third dose and assessed a possible correlation with age, time between transplant and vaccination, and type of immunosuppressive therapy.ResultsA total of 98 of the 176 patients (55.7%) responded positively after the inoculation of the second dose and according to the multivariable logistic regression analysis the lack of seroconversion was independently associated with patient age ≥60 (P = .025; odds ratio [OR], 2.094), time since transplant of 1 to 3 months (P = .032; OR, 2.118), and triple therapy (P = .044; OR, 2.327). After the vaccine third dose, the seroconversion increased to 62.5%, and it was negatively influenced by calcineurin inhibitor use (12/21, 57.1% vs 71/78, 91.0%, P = .0006) and triple therapy (13/21, 61.9% vs 72/78, 92.3%, P = .0014). The median of antispike antibody response significantly increased from 18.5 IU/mL after the second dose to 316.9 IU after the third dose (P < .0001).ConclusionsWe demonstrated a correlation between older age and shorter distance from the transplant and triple immunosuppressive therapy with the lack of seroconversion. We noticed a significant improvement in antibody response by a third dose of messenger RNA vaccine.     

Cellular immunity predominates over humoral immunity after homologous and heterologous mRNA and vector-based COVID-19 vaccine regimens in solid organ transplant recipients

Knowledge on the immunogenicity of vector-based and mRNA-vaccines in solid organ transplant recipients is limited. Therefore, SARS-CoV-2–specific T cells and antibodies were analyzed in 40 transplant recipients and 70 controls after homologous or heterologous vaccine-regimens. Plasmablasts and SARS-CoV-2–specific CD4 and CD8 T cells were quantified using flow cytometry. Specific antibodies were analyzed by ELISA and neutralization assay. The two vaccine types differed after the first vaccination, as IgG and neutralizing activity were more pronounced after mRNA priming (p = .0001 each), whereas CD4 and CD8 T cell levels were higher after vector priming (p = .009; p = .0001). All regimens were well tolerated, and SARS-CoV-2–specific antibodies and/or T cells after second vaccination were induced in 100% of controls and 70.6% of transplant recipients. Although antibody and T cell levels were lower in patients, heterologous vaccination led to the most pronounced induction of antibodies and CD4 T cells. Plasmablast numbers were significantly higher in controls and correlated with SARS-CoV-2–specific IgG- and T cell levels. While antibodies were only detected in 35.3% of patients, cellular immunity was more frequently found (64.7%) indicating that assessment of antibodies is insufficient to identify COVID-19-vaccine responders. In conclusion, heterologous vaccination seems promising in transplant recipients, and combined analysis of humoral and cellular immunity improves the identification of responders among immunocompromised individuals.     

Humoral Response After SARS-CoV-2 Vaccination in Kidney Transplant Recipients: Role of Immunosuppression Therapy

BackgroundMessenger RNA vaccination against COVID-19 has been shown to produce an immune response with sufficient efficacy to prevent natural infection in immunocompetent recipients. However, the response in kidney transplant recipients is low. We aimed to evaluate the specific humoral response to SARS-CoV-2 after vaccination in a population of kidney transplant recipients and assess the main factors associated with a lack of response.MethodsWe undertook a prospective study of 105 kidney transplant recipients and 11 recipients of a combined kidney-pancreas transplant. We analyzed immunoglobulin G and immunoglobulin M antibodies after the patients received their second and third doses of the messenger RNA 1273 (Moderna) or BNT162b1 (BionTECH-Pfizer) vaccinations between February and November 2021.ResultsMean (SD) age of the 116 patients was 50 (16) years, and 65% were men. They had their transplants for 40 months (IQR, 15-123 months), with 14% undergoing retransplant and 11% sensitized. The maintenance immunosuppression regimen was steroids + tacrolimus + mycophenolate (MMF) in 68% of the patients and any combination with mammalian target of rapamycin inhibitor (mTORi) in 28%. A humoral response developed in 40% of the patients 6 weeks (IQR, 4-10 weeks) after receiving the second dose of the vaccine. Of the 67 patients with no response to the second dose, 51 had an analysis of the humoral response after the third dose, which was positive in 16 (31%). A total of 80% received the Moderna vaccine and 20% the BionTECH-Pfizer. No patient experienced major adverse effects after the vaccination.Factors associated with a lack of humoral response to the vaccine were recipient age (odds ratio [OR], 1.02; 95% CI, 1.001-1.05; P = .04), diabetes (OR, 2.8; 95% CI, 1.2-6.9; P = .02), and treatment with MMF (OR, 2.6; 95% CI, 1.08-6.8; P = .03). Treatment with mTORi was associated with a better response to vaccination (OR, 0.3; 95% CI, 0.1-0.9; P = .04).ConclusionsThe humoral response to the COVID-19 vaccine in kidney transplant recipients is poor. Factors related with this lack of immunity are recipient age and diabetes, plus MMF therapy, whereas mTORi therapy was associated with a better response to vaccination.     

Mortality Due to COVID-19 in Renal Transplant Recipients,Related to Variants of SARS-CoV-2 and Vaccination in Mexico

BackgroundSARS-CoV-2 infection in transplant patients has shown greater lethality and vaccination in this group of patients has shown less information. The objective of this study is to show the statistics in Mexico of lethality in kidney recipients infected with COVID-19 in relation to vaccination and variants of the coronavirus.MethodsThis is a bibliographic search of kidney transplant recipient patients since the start of the pandemic in Mexico to determine lethality after SARS-CoV-2 compared to the general population and in relation to patients, the 4 most important infectious peaks in the country due to identified variants, and also before and after vaccination.ResultsThe global lethality is 26.91% from the beginning of the pandemic to April 9, 2022 in kidney recipients in Mexico (130 deaths of 483 infected kidney transplant recipients) compared to the national lethality of 5.60%. Variant B. 1.1.220 represented the highest lethality with 30.43% and the lowest lethality was Omicron with 16.41%. The lethality prior to vaccination was 30.94% and 23.46% after it.ConclusionBoth some variants and vaccination have influenced a lower lethality due to COVID-19 in Mexico in kidney transplant patients; It is important to consider global recommendations, such as a third or fourth dose, a combination of mRNA vaccines and vectors in order to reduce lethality in this group of patients.     

The Course of SARS-CoV-2 in a Patient After a Recent Kidney Transplant: A Literature Review on COVID-19 Therapy

BackgroundKidney transplant recipients are at high risk of severe complications and death due to coronavirus disease 2019 (COVID-19).MethodsThe first part of the article describes a case of COVID-19 in our patient after a recent kidney transplant. The second part of the article presents the outcome of literature search from multiple resources from April 2020 until March 2021. Abstracts were screened, followed by full-text review with data extraction. Part 2 discusses current treatment options of COVID-19, and part 3 refers to this treatment application in patients after solid organ transplant.ResultsWe have summarized 45 studies from China, France, Italy, Spain, the United Kingdom, and the United States. Mortality rates from published studies were variable. Based on early data from Spain, 42% of patients who developed COVID-19 within 60 days of transplant died. According to results of the European Renal Association COVID-19 Database collaboration group, the 28-day COVID-19–related mortality is 21.3% for kidney transplant recipients, which is still markedly higher than what is observed in other populations. Acute kidney injury was common, and mycophenolate mofetil and mammalian target of rapamycin were discontinued in most patients.ConclusionsEffective therapy has been sought since the outbreak of the pandemic, and at the same time intensive work has been done to produce a vaccine that could effectively protect against the disease. Summing up the efforts of numerous groups of researchers from around the world that have been continued since the beginning of 2020, we may assume the following:(1) we still do not have causal drugs that would reduce severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication and allow its complete elimination, but antispike monoclonal antibodies against SARS-CoV-2 seem to be very promising, and (2) the withdrawal of antiproliferative and antimetabolic drugs and the continuation of steroids and calcineurin inhibitors is now a commonly accepted approach in patients after organ transplant.     

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.