Fifth bivalent omicron BA.4/BA.5 vaccination neutralization of SARS-CoV-2 in heart transplant recipients.

In 2022, the antigenically divergent SARS-CoV-2 omicron variants (BA.1, BA.2, BA.4, BA.5) outcompeted previous variants and continued to cause substantial numbers of illnesses and deaths. We evaluated the safety and immunogenicity of the bivalent original/omicron BA.4/BA.5 Pfizer/BioNTech vaccine administered as a fifth dose to heart transplant recipients (HTxRs). We compared neutralization (using live virus assays) of SARS-CoV-2-infected cells in serum samples from HTxRs who had previously received 4 doses of the monovalent BNT162b2 vaccine with samples from HTxRs with breakthrough infection after 4 monovalent BNT162b2 doses. The fifth vaccination induced high neutralization efficiency against the wild-type virus and omicron BA.1, BA.2, BA.4, and BA.5 variants, with significantly higher neutralization efficiency being induced in HTxRs with breakthrough infection than in those without. Neutralizing titers in those with breakthrough infection were sustained above the level induced by the fifth dose in the uninfected. We conclude that the fifth bivalent vaccine is immunogenic, including to variants, with higher vaccine immunogenicity conferred by breakthrough infection. Nevertheless, the clinical protection conferred by the fifth dose is yet to be determined. The sustained neutralization responses in those with breakthrough infection support the notion of delaying booster in those with natural breakthrough infection.

Excess risk for acute myocardial infarction mortality during the COVID-19 pandemic.

The COVID-19 pandemic has had a detrimental impact on the healthcare system. Our study armed to assess the extent and the disparity in excess acute myocardial infarction (AMI)-associated mortality during the pandemic, through the recent Omicron outbreak. Using data from the CDC's National Vital Statistics System, we identified 1 522 669 AMI-associated deaths occurring between 4/1/2012 and 3/31/2022. Accounting for seasonality, we compared age-standardized mortality rate (ASMR) for AMI-associated deaths between prepandemic and pandemic periods, including observed versus predicted ASMR, and examined temporal trends by demographic groups and region. Before the pandemic, AMI-associated mortality rates decreased across all subgroups. These trends reversed during the pandemic, with significant rises seen for the youngest-aged females and males even through the most recent period of the Omicron surge (10/2021-3/2022). The SAPC in the youngest and middle-age group in AMI-associated mortality increased by 5.3% (95% confidence interval [CI]: 1.6%-9.1%) and 3.4% (95% CI: 0.1%-6.8%), respectively. The excess death, defined as the difference between the observed and the predicted mortality rates, was most pronounced for the youngest (25-44 years) aged decedents, ranging from 23% to 34% for the youngest compared to 13%-18% for the oldest age groups. The trend of mortality suggests that age and sex disparities have persisted even through the recent Omicron surge, with excess AMI-associated mortality being most pronounced in younger-aged adults.

Kinetics of cellular and humoral responses to third BNT162B2 COVID-19 vaccine over six months in heart transplant recipients - implications for the omicron variant.

BACKGROUND: The durability of the immune response following the 3-dose BNT162b2 vaccination is unknown. The complexity of the situation is enhanced by the threat that highly transmissible variants may further accelerate the decline in the protection afforded by mRNA vaccines. METHODS: One hundred and three 3-dose-vaccinated heart transplant recipients were longitudinally assessed for the kinetics of variant-specific neutralization (Cohort 1, n = 60) and SARS-CoV-2-specific-T-cell response (Cohort 2, n = 54) over 6 months. Neutralization and T-cell responses were compared between paired samples at 2 time points, using the Kruskal-Wallis test followed by Dunn's multiple comparison test for continuous variables and McNemar's test for dichotomous variables. The Bonferroni method of p values adjustment for multiple comparison was applied. RESULTS: The third dose induced high neutralization of the wild-type virus and delta variant (geometric mean titer [GMT], 137.2 [95% CI, 84.8-221.9] and 80.6, [95% CI, 49.3-132.0], respectively), and to a lesser degree of the omicron variant (GMT, 10.3 [95% CI, 5.9-17.9]). At 6 months, serum neutralizing activity declined but was still high for the wild-type virus and for the delta variant (GMTs 38.1 [95% CI, 21.2-69.4], p = 0.011; and 28.9 [95% CI, 16.6-52.3], p = 0.022, respectively), but not for the omicron variant (GMT 5.9 [95% CI, 3.4-9.8], p = 0.463). The percentages of neutralizing sera against the wild-type virus, delta and omicron variants increased from 70%, 65%, and 38%, before the third dose, to 93% (p < 0.001), 88% (p < 0.001), and 48% (p = 0.021) at 3 weeks after, respectively; and remained high through the 6 months for the wild-type (80%, p = 0.06) and delta (77%, p = 0.102). The third dose induced the development of a sustained SARS-CoV-2-specific-T-cell population, which persisted through 6 months. CONCLUSIONS: The third BNT162b2 dose elicited a durable SARS-CoV-2-specific T-cell response and induced effective and durable neutralization of the wild-type virus and the delta variant, and to a lesser degree of the omicron variant.

Heart transplant recipient 1-year outcomes during the COVID-19 pandemic.

The COVID-19 pandemic initially brought forth considerable challenges to the field of heart transplantation. To prevent the spread of the virus and protect immunocompromised recipients, our center made the following modifications to post-transplant outpatient management: eliminating early coronary angiograms, video visits for postoperative months 7, 9, and 11, and home blood draws for immunosuppression adjustments. To assess if these changes have impacted patient outcomes, the current study examines 1-year outcomes for patients transplanted during the pandemic. Between March and September 2020, we assessed 50 heart transplant patients transplanted during the pandemic. These patients were compared to patients who were transplanted during the same months between 2011 and 2019 (n = 482). Endpoints included subsequent 1-year survival, freedom from cardiac allograft vasculopathy, any-treated rejection, acute cellular rejection, antibody-mediated rejection, nonfatal major adverse cardiac events (NF-MACE), and hospital and ICU length of stay. Patients transplanted during the pandemic had similar 1-year endpoints compared to those of patients transplanted from years prior apart from 1-year freedom from NF-MACE which was significantly higher for patients transplanted during the pandemic. Despite necessary changes being made to outpatient management of heart transplant recipients, heart transplantation continues to be safe and effective with similar 1-year outcomes to years prior.

Fourth BNT162b2 vaccination neutralization of omicron infection after heart transplantation.

We investigated changes in receptor-binding domain IgG and neutralizing antibodies against the omicron and delta variants, vs the wild-type virus, in response to a fourth BNT162b2 dose in 90 heart transplant (HT) recipients. The fourth dose induced anti-RBD IgG antibodies and a higher neutralization efficiency against the wild-type virus and the variants; however, neutralization efficiency against the omicron variant was lower than that against the delta variant (the latter demonstrating efficacy similar to that against the wild-type virus). Notably, while IgG anti-RBD antibodies were detectable in >80% of the HT recipients, only about half demonstrated neutralization efficiency against the omicron variant. A SARS-CoV-2-specific-T-cell response following the fourth dose was evident in the majority of transplant recipients. Boosting vulnerable groups improves antibody responses (including neutralizing responses) and cellular immunity, but the incomplete immunological response, particularly for omicron, suggests continued preventive measures and optimization of vaccination strategies that elicit strong, and long-lasting immune responses, in this high-risk population, should remain a priority.

Heart transplantation in the era of the SARS-CoV-2 pandemic: Is it safe and feasible?

As the SARS-CoV-2-pandemic continues to unfold, the number of heart transplants completed in the United States has been declining steadily. The current case series examines the immediate short-term outcomes of seven heart transplant recipients transplanted during the SARS-CoV-2 pandemic. We hope to illustrate that with proper preparation, planning, and testing, heart transplantation can be continued during a pandemic. We assessed 7 patients transplanted from March 4, 2020, to April 15, 2020. The following endpoints were noted: in-hospital survival, in-hospital freedom from rejection, in-hospital nonfatal major cardiac adverse events (NF-MACE), severe primary graft dysfunction, hospital length of stay, and ICU length of stay. There were no expirations throughout the hospital admission. In addition, there were no patients with NF-MACE or treated rejection, and 1 patient developed severe primary graft dysfunction. Average length of stay was 17.2 days with a standard deviation of 5.9 days. ICU length of stay was 7.7 days with a standard deviation of 2.3 days. Despite the decreasing trend in completed heart transplants due to SARS-CoV-2, heart transplantation appears to be feasible in the immediate short term. Further follow-up is needed, however, to assess the impact of SARS-CoV-2 on post-heart transplant outcomes months after transplantation.