Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 6 4 2022 06 23 e56 e56 Zahra Ebadi Multiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran Fereshteh Ghadiri Multiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran Elnaz Asadollahzade Multiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran Abdorreza Naser Moghadasi Multiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran 2022 06 18 2022 06 23 Shortly after the onset of the coronavirus pandemic, different vaccines were developed to combat it. The vaccines had different mechanisms and triggered cellular and humoral immune responses against the virus. In addition to their positive effects, various side effects have been reported for them. They rarely cause severe complications. They can also rarely trigger latent infections. The present case report presents a patient who developed herpes simplex encephalitis after receiving the second dose of the Covaxin (BBV152). https://fem.tums.ac.ir/index.php/fem/article/view/1025 https://fem.tums.ac.ir/index.php/fem/article/download/1025/412