Mucormycosis, past and present: a comprehensive review.

Mucormycosis is an emerging opportunistic angioinvasive fungal infection. Predisposing factors such as diabetes, neutropenia, long-term corticosteroid therapy, solid organ transplantation and immunosuppression contribute to its occurrence. This disease was not of significant concern prior to the COVID-19 pandemic, but gained prominence due to infections in COVID-19 patients. Mucormycosis needs special attention and coordinated efforts of the scientific community and medical professionals to reduce morbidity and mortality. Here we present an overview of the epidemiology and prevalence of mucormycosis in the pre- and post-COVID-19 eras, the factors that contributed to the abrupt increase in COVID-19-associated mucormycosis (CAM), the actions taken by the regulatory agencies (including Code Mucor and CAM registry), the existing diagnostic tools and CAM management strategies.

The devastating effects of the COVID-19 pandemic have been further enhanced by various secondary illnesses, particularly opportunistic fungal infections such as mucormycosis. Mucormycosis or 'black fungus' primarily affects people with weakened immunity, those with medical conditions such as diabetes or cancer and those who use medications that reduce the body's capacity to resist infections and disease. The infection starts in the sinuses or the lungs after breathing in spores of the black fungus from the air. In just 2 months between 5 May and 12 July 2021, this uncommon but fatal fungal illness was responsible for 41,512 cases and 3554 fatalities in India alone. The government of India declared a mucormycosis epidemic in May 2021. The majority of such cases occurred during active SARS-CoV-2 outbreaks in India in 2021. Black fungus took over while the host defenses were compromised and the globe was preoccupied tackling the COVID-19 pandemic. Steroids prescribed in amounts and time spans that far exceeded WHO recommendations to manage severe COVID-19 cases, potentially weakened patients' immune systems, and raised blood sugar levels making them vulnerable to fungal invasion. Early diagnosis and treatment are the keys to a patient's survival. Simple means such as maintaining hygienic conditions, avoiding contact with an infected person, judiciously using steroid medications and antibiotics and properly managing high blood sugar can help protect an individual from black-fungus infection.

Immunological Mechanisms of Vaccine-Induced Protection against SARS-CoV-2 in Humans

The SARS-CoV-2 infection spread rapidly throughout the world and appears to involve in both humoral and cell-mediated immunity. SARS-CoV-2 is attached to host cells via binding to the viral spike (S) proteins and its cellular receptors angiotensin-converting enzyme 2 (ACE2). Consequently, the S protein is primed with serine proteases TMPRSS2 and TMPRSS4, which facilitate the fusion of viral and cellular membranes result in the entry of viral RNA into the host cell. Vaccines are urgently required to combat the coronavirus disease 2019 (COVID-19) outbreak and aid in the recovery to pre-pandemic levels of normality. The long-term protective immunity is provided by the vaccine antigen (or pathogen)-specific immune effectors and the activation of immune memory cells that can be efficiently and rapidly reactivated upon pathogen exposure. Research efforts aimed towards the design and development of vaccines for SARS-CoV-2 are increasing. Numerous coronavirus disease 2019 (COVID-19) vaccines have passed late-stage clinical investigations with promising outcomes. This review focuses on the present state and future prospects of COVID-19 vaccines research and development, with a particular emphasis on immunological mechanisms of various COVID-19vaccines such as adenoviral vector-based vaccines, mRNA vaccines, and DNA vaccines that elicits immunological responses against SARS-CoV-2 infections in humans.