When news of a novel coronavirus emerged three years ago, no one could have predicted the extent of its impact, which continues to be felt as of December 2022. Undoubtedly one of the most significant experiences of our lifetime, we can all surely recall our first memory of hearing about “COVID-19”: where we were, our first impressions, and how we envisioned the course of this novel coronavirus, SARS-CoV-2. Whether you first thought it would be transient or an outbreak that would strike us hard, few would have expected the staggering worldwide pandemic that has deeply affected all areas of medicine, politics, and the economy — one that continues to impact all aspects of our lives.
As the COVID-19 pandemic continues to evolve, hematologists have been integral to the care and management of this disease, and the Presidential Symposium on Tuesday, December 13, What the Hematologist Has Learned From the Pandemic, addressed the role hematologists have played in these unprecedented times. From managing the numerous unanticipated effects of the virus, including thrombosis and thrombocytopenia, to facing its devasting impact on our immunocompromised patients with hematologic malignancies, hematologists from around the world were called upon. While we were fortunate to develop a highly effective vaccine within months, the rare hematologic complications of the COVID-19 vaccine itself, and its inability to consistently protect our immunocompromised patients, continue to affect our field.
An all-star team guided us through the symposium, including Dr. Jane N. Winter, president of ASH, opening the with an introduction of the hematologist’s role in the COVID-19 pandemic. The session started with Dr. Beverly Hunt, a professor of thrombosis and hemostasis at Kings College London; when it comes to the field of thrombosis, there are few names bigger than hers. In case you haven’t ever heard of World Thrombosis Day, held on October 13, Dr. Hunt is the Steering Committee Chair of this incredible initiative that helps spread awareness and raise funds for thrombosis research. She has also been instrumental in setting up thrombosis patient support groups that have led to increased awareness, improved outcomes, and prioritization of research funding for thrombosis. Her talk did not disappoint, as she reviewed coagulopathies/thromboses, vaccine-induced immune thrombotic thrombocytopenia (VITT), and thrombocytopenic complications associated with COVID-19 infection and vaccination.
Dr. Hunt began with a discussion of provoked thrombosis in acute COVID-19 infection. She noted the association between severity of disease and rates of venous thromboembolism (VTE) including immunothrombotic pulmonary emboli. Next, she reviewed studies revealing the benefit of therapeutic heparin in selected patients with COVID-19 infection, and the struggle to implement uniformity in anticoagulation practice. In 2021, her team identified VITT, and she shared her teams incredible efforts in defining these rare vaccine associated adverse events. Lastly, she discussed long COVID and the recent media fascination with the role of “micro-clots” in long COVID. This inadequately studied area has resulted in indiscriminate use of anticoagulation and plasmapheresis in private clinics that may be causing significant harm to patients. This session was packed with fascinating information on the association of thrombosis and COVID-19, and it certainly highlighted the continued vital role of hematologists in managing this pandemic.
The symposium next featured Dr. Shane Crotty, professor at the La Jolla Institute of Immunology and world-renowned expert in assessing the human immune response to infection and vaccines, who discussed T-cell response to SARS-CoV-2 infection and vaccination. Measurement of immunity goes beyond just antibody levels - as we recall from our immunology courses. Dr. Shane Crotty presented an enlightening summary of the knowledge to date of the immune response to COVID-19 vaccination and infection, and it was reassuring indeed to review the multiple layers of immune defense that develop with both immunization and infections, through what Dr. Crotty called the “layered defense” or “Swiss cheese model of immunity.” While antibody titers indicate protection, there are still notable CD4 and CD8 T-cell, as well as memory B cell responses present even in the absence of antibody titers, which appear to predictably fall while other areas of our immune system strengthen with time. The pivotal role of T cells in generating immunity after infections and vaccinations is a concept that can provide at least partial reassurance to hematologists. It is also promising that there seems to be long-term (at least years) protection following all forms of vaccination and infection, and immunity even against newer variants of the virus due to our magnificent germinal centers.
Finally, Dr. Drew Weissman took the stage to discuss the COVID-19 mRNA vaccinations. Dr. Weissman and his collaborator Dr. Katalin Kariko are credited with developing the mRNA technology that made the Covid-19 vaccines possible. He spoke about his journey toward acceptance of mRNA technology as a potential therapeutic avenue and the hurdles he and Dr. Kariko faced. Building upon his success (after having overcome all these hurdles), he spoke about the new mRNA vaccines in development, including those with targeted lipid nanoparticle delivery systems. This concept is also being applied to the in vivo generation of CAR T-cells, in vivo gene therapies, and protein replacement. Exciting times for our field!
No area of medicine, or arguably of our lives, has been spared from the widespread effects of the COVID-19 global pandemic. As hematologists, we were sought out for many reasons during the pandemic, and though we have come a long way and learned many lessons with far-reaching implications, our work is not over yet. The Presidential Symposium captured many of the strides we have made in a beautiful fashion, leaving us inspired and hopeful for our future.
Dr. Vardell and Dr. Mohyuddin indicated no relevant conflicts of interest.
