A novel coronavirus, or severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), was identified as the causative agent of coronavirus disease 2019 (COVID‐19). In early 2020, the World Health Organization declared COVID‐19 the sixth public health emergency of international concern. The COVID‐19 pandemic has substantially affected many groups within the general population, but particularly those with extant clinical conditions, such as having or being treated for cancer. Cancer patients are at a higher risk of developing severe COVID‐19 since the malignancy and chemotherapy may negatively affect the immune system, and their immunocompromised condition also increases the risk of infection. Substantial international efforts are currently underway to develop specific methods for diagnosing and treating COVID‐19. However, cancer patients’ risk profiles, management, and outcomes are not well understood. Thus, the main objective of this review is to discuss the relevant evidence to understand the prognosis of COVID‐19 infections in cancer patients more clearly, as well as helping to improve the clinical management of these patients.

Summary Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is a crucial step in ending the current worldwide pandemic. However, several particularly vulnerable groups in the population were not included in sufficient numbers in coronavirus disease 2019 (Covid‐19) vaccine trials. Therefore, as science advances, the advice for vaccinating these special populations against Covid‐19 will continue to evolve. This focused review provides the latest recommendations and considerations for these special populations (i.e., patients with rheumatologic and autoimmune disorders, cancer, transplant recipients, chronic liver diseases, end‐stage renal disease, neurologic disorders, psychiatric disorders, diabetes mellitus, obesity, cardiovascular diseases, chronic obstructive pulmonary disease, human immunodeficiency virus, current smokers, pregnant and breastfeeding women, the elderly, children, and patients with allergic reactions) using the currently available research evidence.

Human monkeypox is a zoonotic Orthopoxvirus resembling smallpox in clinical course, making it difficult to distinguish it from smallpox and varicella. Laboratory diagnostics are critical components of illness identification and surveillance, and novel tests are required for more precise and quick diagnosis. The majority of human infections occur in Central Africa, where monitoring in remote regions with little infrastructure is challenging but may be performed using evidence-based methods and teaching materials that educate public health personnel on the fundamental principles of this infection. New medications and vaccinations showed promising results for the treatment and prevention of the disease, but more studies are required to show their efficacy in the actual endemic settings. Thus, more studies are needed on the virus’s epidemiology, ecology, and biology in endemic locations to better understand and prevent human infections. This review discussed the etiology, epidemiology, and clinical course of the monkeypox and indicated diagnostic and treatment approaches for this disease.

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, there have been multiple peaks of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus virus 2) infection, mainly due to the emergence of new variants, each with a new set of mutations in the viral genome, which have led to changes in the pathogenicity, transmissibility, and morbidity. The Omicron variant is the most recent variant of concern (VOC) to emerge and was recognized by the World Health Organization (WHO) on 26 November 2021. The Omicron lineage is phylogenetically distinct from earlier variants, including the previously dominant Delta SARS-CoV-2 variant. The reverse transcription–polymerase chain reaction (RT–PCR) test, rapid antigen assays, and chest computed tomography (CT) scans can help diagnose the Omicron variant. Furthermore, many agents are expected to have therapeutic benefits for those infected with the Omicron variant, including TriSb92, molnupiravir, nirmatrelvir, and their combination, corticosteroids, and interleukin-6 (IL-6) receptor blockers. Despite being milder than previous variants, the Omicron variant threatens many lives, particularly among the unvaccinated, due to its higher transmissibility, pathogenicity, and infectivity. Mounting evidence has reported the most common clinical manifestations of the Omicron variant to be fever, runny nose, sore throat, severe headache, and fatigue. This review summarizes the essential features of the Omicron variant, including its history, genome, transmissibility, clinical manifestations, diagnosis, management, and the effectiveness of existing vaccines against this VOC.

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused many complications, the invention of coronavirus disease 2019 (COVID-19) vaccines has also brought about several adverse events, from common side effects to unexpected and rare ones. Common vaccine-related adverse reactions manifest locally or systematically following any vaccine, including COVID-19 vaccines. Specific side effects, known as adverse events of particular interest (AESI), are unusual and need more evaluation. Here, we discuss some of the most critical rare adverse events of COVID-19 vaccines.