Mass vaccination against coronavirus disease 19 (COVID-19) has effectively controlled the pandemic and has been remarkably effective and safe. Reports of a few adverse events have been reported after post-marketing surveillance. We present a rare case of multiple sclerosis (MS) relapse in a female who presented with fatigue, involuntary eye movements, and numbness; autoimmunity following the COVID-19 vaccine has also been described. She was diagnosed with MS six years back and was in remission. She received her COVID-19 vaccine 18 days ago. Her clinical and radiological features confirmed the MS relapse. Her serology for COVID-19 immunoglobulin G (IgG) and IgM was positive, and she was managed with intravenous methylprednisolone and symptomatic management. Our case provides a possible association of vaccine-associated MS relapse; however, more evidence is warranted from future studies.

BACKGROUND: Myocarditis is being increasingly reported as a potential complication of both Pfizer-BioNTech and Moderna vaccines for COVID-19. One thousand five hundred and twenty-two cases were reported as of September 02, 2021, as per CDC\'s (Centers for Disease Control) vaccine adverse event reporting system. Most of the published data is available in the form of case reports and series. There is a need to compile the demographic data, clinical features, and outcomes in these patients.  Methods: A systematic search was conducted in PubMed, Embase, Web of science, and google scholar for published literature between January 01, 2020, and July 17, 2021. Individual data of 69 patients were pooled from 25 qualifying case reports and case series.
RESULTS: The median age of onset was 21 years. 92.7% of the patients were male. 76.8% of patients received the Pfizer-BioNTech vaccine, and 23.2% received the Moderna vaccine. 88.5% developed symptoms after the second dose. Patients were admitted to the hospital a median of three days post-vaccination. All the patients had chest pain and elevated troponin. The myocarditis was confirmed on cardiac MRI in 87% of the patients. Most of the patients had late gadolinium enhancement on MRI. The median length of stay was four days. All the reported patients recovered and were discharged.
CONCLUSIONS: Post-mRNA vaccination myocarditis is seen predominantly in young males within a few days after their second dose of vaccination. The pathophysiology of myocarditis is not well known. The prognosis is good as all the reported patients recovered. The presence of late gadolinium enhancement on cardiac MRI indicated myocardial necrosis/fibrosis and further studies are needed to establish the long-term prognosis of the condition.

COVID-19, which was first detected in the Hubei province of China, has become a global phenomenon. The effects and devastation on both health and economy have been global. At present, there is a substantial amount of research being done to discover suitable treatment modalities. Efforts have been made on the development of potential efficacious vaccines. The development of a vaccine can be complex, expensive as well as time-consuming. Currently, various ongoing clinical trials are in progress that are investigating either pharmacologic therapies or vaccines against this virus. We, in this brief review have tried to address the process and current development efforts of vaccine in progress.