Recent developments in the immunopathology of COVID‐19

Abstract

There has been an important change in the clinical characteristics and immune profile of Coronavirus disease 2019 patients during the pandemic thanks to the extensive vaccination programs. Here, we highlight recent studies on COVID-19, from the clinical and immunological characteristics to the protective and risk factors for severity and mortality of COVID-19. The efficacy of the COVID-19 vaccines and potential allergic reactions after administration are also discussed. The occurrence of new variants of concerns such as Omicron BA.2, BA.4, and BA.5 and the global administration of COVID-19 vaccines have changed the clinical scenario of COVID-19. Multisystem inflammatory syndrome in children (MIS-C) may cause severe and heterogeneous disease but with a lower mortality rate. Perturbations in immunity of T cells, B cells, and mast cells, as well as autoantibodies and metabolic reprogramming may contribute to the long-term symptoms of COVID-19. There is conflicting evidence about whether atopic diseases, such as allergic asthma and rhinitis, are associated with a lower susceptibility and better outcomes of COVID-19. At the beginning of pandemic, the European Academy of Allergy and Clinical Immunology (EAACI) developed guidelines that provided timely information for the management of allergic diseases and preventive measures to reduce transmission in the allergic clinics. The global distribution of COVID-19 vaccines and emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with reduced pathogenic potential dramatically decreased the morbidity, severity, and mortality of COVID-19. Nevertheless, breakthrough infection remains a challenge for disease control. Hypersensitivity reactions (HSR) to COVID-19 vaccines are low compared to other vaccines, and these were addressed in EAACI statements that provided indications for the management of allergic reactions, including anaphylaxis to COVID-19 vaccines. We have gained a depth knowledge and experience in the over 2 years since the start of the pandemic, and yet a full eradication of SARS-CoV-2 is not on the horizon. Novel strategies are warranted to prevent severe disease in high-risk groups, the development of MIS-C and long COVID-19.

Aging and long COVID-19 syndrome: what’s new in 2023?

“…As of 2023, however, even though it appears that, 10-35% of COVID survivors develop long COVID, with common symptoms including fatigue, breathlessness, chest pain, cough, depression, anxiety, features of post-traumatic stress disorder, memory loss, and difficulty concentrating, what percentage are over 65 years of age, and what their specific issues are is not documented. As per Hueme et al, 57 and Sherestha et al, 58 delineating these and other mechanistic issues, such as endothelial damage and immunological associated factors 59,60 using more universal definitions and focused research approaches should help to better inform and support any potentially beneficial post-pandemic health policy and public health protection efforts against long COVID-19 syndrome, and its apparent persistently adverse health impacts and immense social costs among both the older population and others. 61,62…”

A Prospective Cohort Study of COVID-19: Evaluation of the Early Role of IL-1 and IL-6 Antagonists in Improving the Outcome of the Illness and Reduction in the Risk of Death

“…Treatment should then include therapies that target the virus or the immune response to the virus [ 10 , 38 ]. The severity of the infection could be due mainly to the immune response overactivation that in turn results in a cytokine storm syndrome, which can be life-threatening [ 3 , 40 ]. The COVID-19 pandemic has highlighted the importance of immunomodulatory medications such as corticosteroids, IL-6 inhibitors, or IL-1 receptor antagonists, in dampening the immune response and reducing inflammation [ 32 , 40 ].…”

“…The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has affected the world in an unprecedented manner. The virus has led to a massive surge in global morbidity and mortality, with over 150 million cases and over 3 million deaths reported as of early 2023 [3][4][5]. The virus primarily infects the respiratory tract and causes a wide range of symptoms, ranging from mild cold-like symptoms to severe pneumonia and multi-organ failure [6][7][8][9].…”

Does allergen immunotherapy impact the susceptibility and severity of COVID-19？

“…To the editor, Allergic asthma (AA) and allergic rhinitis (AR) might be protective against SRAS-CoV-2 infection and progress to severe disease of coronavirus disease 2019 (COVID-19) 1 . COVID-19 vaccination was safe and well tolerated in patients receiving allergen immunotherapy (AIT) 2,3 , and the adherence to subcutaneous immunotherapy (SCIT) was not affected during COVID-19 pandemic 4 .…”