The hidden unicuspid: Recurring aortic stenosis post-valvuloplasty from a unicuspid aortic valve masquerading as bicuspid.

Unicuspid aortic valves (UAV) account for 0.2 % of cardiac valvular disorders and present with early-onset aortic stenosis (AS) during adolescence or early adulthood. We present a case of a 17-year-old male with recurring AS. He was diagnosed with bicuspid aortic valve (BAV) two years previously and treated with balloon valvuloplasty, which relieved symptoms before that. Multimodality imaging work-up revealed the precise morphology of UAV, consistent with the surgical findings. The patient received a St. Jude mechanical valve (St Paul; MN, USA) which resolved his symptoms. A thorough radiologic evaluation is therefore required for the accurate diagnosis of UAVs. While 2-dimensional (2D) transthoracic echocardiography (TTE) often constitutes the initial modality for evaluating UAVs, 3D-TTE, transesophageal echocardiography, and cardiac computed tomography are used as confirmatory diagnostic tools. Balloon valvuloplasty reports good outcomes in BAV but is associated with an increased rate of symptom recurrence, repeated surgical procedures, and higher mortality in UAVs, underscoring the importance of an accurate pre-operative diagnosis. Learning objectives: 1.Unicuspid aortic valve (UAV) should be considered in the differential diagnosis of severe aortic stenosis during childhood.2.3D-transthoracic echocardiogram, transesophageal echocardiogram, and cardiac computed tomography (CT) can confirm the diagnosis of a UAV.3.Cardiac CT can additionally assess for accompanying abnormalities of the great vessels in UAV patients.4.Balloon valvuloplasty reports good outcomes in bicuspid aortic valve but is associated with an increased rate of symptom recurrence in UAV patients.

SARS-CoV-2 epitopes inform future vaccination strategies.

All currently approved COVID-19 vaccines utilize the spike protein as their immunogen. SARS-CoV-2 variants of concern (VOCs) contain mutations in the spike protein, enabling them to escape infection- and vaccination-induced immune responses to cause reinfection. New vaccines are hence being researched intensively. Studying SARS-CoV-2 epitopes is essential for vaccine design, as identifying targets of broadly neutralizing antibody responses and immunodominant T-cell epitopes reveal candidates for inclusion in next-generation COVID-19 vaccines. We summarize the major studies which have reported on SARS-CoV-2 antibody and T-cell epitopes thus far. These results suggest that a future of pan-coronavirus vaccines, which not only protect against SARS-CoV-2 but numerous other coronaviruses, may be possible. The T-cell epitopes of SARS-CoV-2 have gotten less attention than neutralizing antibody epitopes but may provide new strategies to control SARS-CoV-2 infection. T-cells target many SARS-CoV-2 antigens other than spike, recognizing numerous epitopes within these antigens, thereby limiting the chance of immune escape by VOCs that mainly possess spike protein mutations. Therefore, augmenting vaccination-induced T-cell responses against SARS-CoV-2 may provide adequate protection despite broad antibody escape by VOCs.

Understanding COVID-19 Vaccines Today: Are T-cells Key Players?

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has heavily mutated since the beginning of the coronavirus-2019 (COVID-19) pandemic. In this regard, the so-called variants of concern (VOCs) feature mutations that confer increased transmissibility and evasion of antibody responses. The VOCs have caused significant spikes in COVID-19 cases, raising significant concerns about whether COVID-19 vaccines will protect against current and future variants. In this context, whereas the protection COVID-19 vaccines offer against the acquisition of infection appears compromised, the protection against severe COVID-19 is maintained. From an immunologic standpoint, this is likely underpinned by the maintenance of T-cell responses against VOCs. Therefore, the role of T-cells is essential to understanding the broader adaptive immune response to COVID-19, which has the potential to shape public policies on vaccine protocols and inform future vaccine design. In this review, we survey the literature on the immunology of T-cell responses upon SARS-CoV-2 vaccination with the current FDA-approved and Emergency Use Authorized COVID-19 vaccines.