COVID vaccination in patients under treatment with rituximab: A presentation of two cases from Iran and a review of the current knowledge with a specific focus on pemphigus.

SARS-COV2 vaccines were approved without long-term monitoring due to emergent situations. This has raised some issues about the timing and protocol of receiving vaccines in specific situations such as patients receiving immunomodulatory agents including rituximab, which is widely used for various disorders such as multiple sclerosis, pemphigus, and many rheumatologic disorders. We described two cases of pemphigus vulgaris (a new case and one with flare-up) following vaccination with Astrazeneca in Iran and reviewed the existing data in this regard through searching on PubMed, Google Scholar, and Scopus. All of the relevant papers published until June 28, 2021, which we could access their full-texts were included. We found some recommendations made by rheumatologists, neurologists, and dermatologists in regard to vaccination timing in this group of patients and tried to summarize them to provide a practical guide for clinicians. Clinicians should perform a careful, individualized risk-benefit assessment for their patients and consider a delay in rituximab administration after completion of COVID vaccination if there is not any considerable risk of disease relapse or organ failure. Moreover, choosing vaccines with potential of providing protection after single dose, especially in countries with limited access to vaccines may be a reasonable approach.