SARS-CoV-2 anti-spike antibodies after vaccination in pediatric heart transplantation: A first report

Serologic Evaluation for Severe Acute Respiratory Syndrome Coronavirus 2 in Pediatric Heart Transplantation Recipients and Patients on a Pediatric Heart Transplantation Waiting List in a Quaternary Hospital

BACKGROUND

The Coronavirus disease 2019 (COVID-19) pandemic has been a global reality for longer than 3 years. Serologic studies have great importance for understanding the virus's behavior in populations, as it can suggest the status of the epidemic in a community. This cross-sectional study aimed to analyze the serologic profile for COVID-19 in patients before and after pediatric heart transplantation.

METHODS

Serology data on IgG and IgM antibodies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were collected in patients of the Pediatric Cardiology and Congenital Heart Diseases unit of a Brazilian hospital between January and August 2022. A total of 174 patients were recruited, including 28 on the transplantation waiting list and 146 heart transplant recipients. Information for each patient, including demographics (age, sex, state of origin), type of heart disease (congenital or acquired), and time after transplantation, was analyzed.

RESULTS

Overall, 72 patients had a positive serology for anti-N antibodies (48.0%), including 62 heart transplant recipients and 10 patients on the transplantation waiting list, The positivity rates in these 2 groups were 48.1% and 47.6%, respectively. Positivity rates for previously infected individuals were 62.5% and 62.1%, respectively.

CONCLUSIONS

Approximately one-half of our study sample had IgM or IgG antibodies against the SARS-CoV-2 virus. Serologic studies on the duration and level of protection provided by these antibodies are relevant public health tools for health promotion of vulnerable groups and can be useful for future studies on antibody behavior.

Measures to Increase Immunogenicity of SARS-CoV-2 Vaccines in Solid Organ Transplant Recipients: A Narrative Review

Purpose of review: To review the data on the immunogenicity of COVID-19 vaccines, administered by different strategies, in solid organ transplant recipients (SOTRs). Recent findings: COVID-19 booster vaccines were given to SOTRs as a widespread practice in many transplant centers, mostly as the third and/or fourth dose in an extended vaccine series, with a significantly improved humoral response compared with the initial two-dose scheme. However, one-third of SOTRs remained unresponsive, despite these boosters. Next steps: Vaccination with standard dosing remains the most feasible strategy for attaining protection against COVID-19. Additional booster doses and temporarily holding or reducing mycophenolate mofetil/mycophenolic acid may provide immunogenicity to vaccines, according to recent studies demonstrating some efficacy with these measures. Preexposure prophylaxis with monoclonal antibodies showed benefit in immunocompromised patients but is no longer recommended by the National Institutes of Health (NIH) due to diminished efficacy against Omicron and recent variants. Screening for the presence and titers of SARS-CoV-2-specific antibodies in SOTRs is not recommended in most clinical settings. T cell-based techniques are needed to evaluate vaccine efficacy and risk of infection. As SARS-CoV-2 continues to evolve, new vaccines based on conservative protein component/complexes of the COVID virus, in addition to its spike protein, are warranted to offer prolonged protection.

Use of REGEN-COV in children after heart transplantation for treatment and post-exposure prophylaxis of COVID-19

COVID-19 pandemic continues to evolve and new variants like Delta and Omicron have been discovered. REGEN-COV is a recombinant human monoclonal antibody to the spike protein of SARS-CoV-2 which received emergency use authorisation for treatment and post-exposure prophylaxis in patients with high risk of progression to severe disease. We review our experience with use of REGEN-COV in paediatric heart transplant patients.

Immunogenicity of COVID-19 vaccines in solid organ transplant recipients: a systematic review and meta-analysis

BACKGROUND

Solid organ transplant (SOT) recipients are at increased risks of morbidity and mortality associated with COVID-19.

OBJECTIVES

This study aimed to evaluate the immunogenicity of COVID-19 vaccines in SOT recipients.

DATA SOURCES

Electronic databases were searched for eligible reports published from 1 December 2019 to 31 May 2022.

STUDY ELIGIBILITY CRITERIA

We included reports evaluating the humoral immune response (HIR) or cellular immune response rate in SOT recipients after the administration of COVID-19 vaccines.

PARTICIPANTS

SOT recipients who received COVID-19 vaccines.

ASSESSMENT OF RISK OF BIAS

We used the Newcastle-Ottawa scale to assess bias in case-control and cohort studies. For randomised-controlled trials, the Jadad Scale was used.

METHODS

We used a random-effects model to calculate the pooled rates of immune response with 95% CI. We used a risk ratio (RR) with 95% CI for a comparison of immune responses between SOT and healthy controls.

RESULTS

A total of 91 reports involving 11 886 transplant recipients (lung: 655; heart: 539; liver: 1946; and kidney: 8746) and 2125 healthy controls revealed pooled HIR rates after the 1st, 2nd, and 3rd COVID-19 vaccine doses in SOT recipients were 9.5% (95% CI, 7-11.9%), 43.6% (95% CI, 39.3-47.8%) and 55.1% (95% CI, 44.7-65.6%), respectively. For specific organs, the HIR rates were still low after 1st vaccine dose (lung: 4.4%; kidney: 9.4%; heart: 13.2%; liver: 29.5%) and 2nd vaccine dose (lung: 28.4%; kidney: 37.6%; heart: 50.3%; liver: 64.5%).

CONCLUSIONS

A booster vaccination enhances the immunogenicity of COVID-19 vaccines in SOT; however, a significant share of the recipients still has not built a detectable HIR after receiving the 3rd dose. This finding calls for alternative approaches, including the use of monoclonal antibodies. In addition, lung transplant recipients need urgent booster vaccination to improve the immune response.

Pediatric solid organ transplant recipients demonstrate robust cell-mediated and humoral responses to three doses of mRNA SARS-CoV-2 vaccine

Pediatric solid organ transplant recipients (pSOTR) often demonstrate suboptimal vaccine responses and are not included in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine efficacy trials. This population has shown variable humoral immunity following SARS-CoV-2 vaccination, and no studies have assessed cell-mediated responses after SARS-CoV-2 vaccination in pSOTR. SARS-CoV-2-specific interferon-gamma release assay (IGRA), immunoglobulin G (IgG), and receptor-binding domain (RBD)-angiotensin-converting enzyme 2 (ACE2) blocking antibody (Ab) were measured in pSOTR aged 5-17 years after 2-3 doses of SARS-CoV-2 mRNA vaccine. In all, 33 subjects were included, with 25 tested after the second dose of mRNA vaccine (V2) and 21 tested after the third dose of mRNA vaccine (V3). Of the 19 subjects who had IgG testing after V3, 100.0% (19/19) had a positive IgG response. Of the 17 subjects who had IGRA testing after V3, 94.1% (16/17) had a positive IGRA response. RBD-ACE2 blocking antibody increased significantly from V2 to V3 (p = .007). Subjects <1 year from transplant demonstrated a significantly larger increase in RBD-ACE2 blocking Ab from V2 to V3 than did those >1 year from transplant (p = .05). SARS-CoV-2 vaccination induces humoral and cell-mediated responses in the majority of pSOTR, with improved quantitative humoral response after three doses.

Humoral and cellular response of COVID-19 vaccine among solid organ transplant recipients: A systematic review and meta-analysis

BACKGROUND

We aimed to analyze the humoral and cellular response to standard and booster (additional doses) COVID-19 vaccination in solid organ transplantation (SOT) and the risk factors involved for an impaired response.

METHODS

We did a systematic review and meta-analysis of studies published up until January 11, 2022, that reported immunogenicity of COVID-19 vaccine among SOT. The study is registered with PROSPERO, number CRD42022300547.

RESULTS

Of the 1527 studies, 112 studies, which involved 15391 SOT and 2844 healthy controls, were included. SOT showed a low humoral response (effect size [ES]: 0.44 [0.40-0.48]) in overall and in control studies (log-Odds-ratio [OR]: -4.46 [-8.10 to -2.35]). The humoral response was highest in liver (ES: 0.67 [0.61-0.74]) followed by heart (ES: 0.45 [0.32-0.59]), kidney (ES: 0.40 [0.36-0.45]), kidney-pancreas (ES: 0.33 [0.13-0.53]), and lung (0.27 [0.17-0.37]). The meta-analysis for standard and booster dose (ES: 0.43 [0.39-0.47] vs. 0.51 [0.43-0.54]) showed a marginal increase of 18% efficacy. SOT with prior infection had higher response (ES: 0.94 [0.92-0.96] vs. ES: 0.40 [0.39-0.41]; p-value < .01). The seroresponse with mRNA-12723 mRNA was highest 0.52 (0.40-0.64). Mycophenolic acid (OR: 1.42 [1.21-1.63]) and Belatacept (OR: 1.89 [1.3-2.49]) had highest risk for nonresponse. SOT had a parallelly decreased cellular response (ES: 0.42 [0.32-0.52]) in overall and control studies (OR: -3.12 [-0.4.12 to -2.13]).

INTERPRETATION

Overall, SOT develops a suboptimal response compared to the general population. Immunosuppression including mycophenolic acid, belatacept, and tacrolimus is associated with decreased response. Booster doses increase the immune response, but further upgradation in vaccination strategy for SOT is required.

Responsiveness to second and third dose of mRNA COVID-19 vaccination in adolescent and young adult heart transplant recipients

BACKGROUND

Third-dose mRNA COVID-19 vaccine is currently recommended in the United States for SOT recipients based in part on data showing diminished immune response, including Ab production, after a two-dose regimen. Data on vaccine response in adolescent and young adult SOT recipients are limited, including no data reported on third-dose responsiveness.

METHODS

Results of serologic testing in a convenience sample of 28 vaccinated adolescent and young adult HT recipients at a single institution were collected from the medical record and summarized.

RESULTS

At a median of 98.5 days (IQR 59-150) after second dose, 17 (61%) had an Ab response. Among 12 who had serology before and after third-dose vaccination, four of seven who were negative prior to third dose became positive at a median of 34 days (IQR 31-39.5) following third dose. No myocarditis, acute rejection, graft dysfunction, graft loss, or deaths were observed.

CONCLUSIONS

These findings support recommendations for the routine administration of three doses of mRNA vaccines in adolescent and young adult HT recipients and show a potential subpopulation in whom the fourth dose should be contemplated.

Immunogenicity of SARS-CoV-2 vaccination in adolescents with cardiac disease

BACKGROUND

Although widely reported to affect older adults more, coronavirus disease 2019 (COVID-19) also affects adolescents, especially those with co-morbidities, including heart diseases. The safety and efficacy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines has been established in healthy adolescents, yet there are few data for humoral and cellular immunogenicity in adolescents with cardiac diseases.

METHODS

We evaluated anti-spike antibodies, neutralizing activities, and interferon-gamma production prior to and after SARS-CoV-2 vaccination in adolescents with cardiac diseases and healthy controls.

RESULTS

Five healthy adolescents and 26 patients with cardiac diseases, including congenital heart disease (CHD, n = 10), dilated cardiomyopathy (DCM, n = 4), idiopathic pulmonary arterial hypertension (IPAH, n = 4), and those post-heart transplantation (post-HTx, n = 8) were enrolled. No severe adverse events, including myocarditis and pericarditis, were noted, even in patients with severe heart failure. Febrile events were noted after 21 of 62 injections (34%). All the healthy adolescents and 21 of the 26 patients (81%) showed sufficient elevation of neutralizing antibodies after the second dose of vaccination. Neutralizing antibodies and cellular immunity were absent in four of the eight post-HTx patients and one with single ventricle CHD. There was no correlation between the anti-spike and neutralizing antibody titers and interferon-gamma levels. When comparing the clinical characteristics of the patients post-HTx who did or did not acquire antibodies, there was no significant difference in the immunosuppressant types and trough levels.

CONCLUSIONS

SARS-CoV-2 mRNA vaccine has efficient immunogenicity for adolescents with CHD, IPAH, and DCM. Half of post-HTx patients could not acquire sufficient humoral immunity.