Background: At the start of the SARS-CoV-2 (COVID-19) pandemic there was uncertainty among Multiple Sclerosis (MS) patients about starting or continuing Disease Modifying Therapies (DMTs). Guidelines have been developed and specialists have agreed that the effective treatment of MS should remain the primary consideration when selecting DMTs1.With the advent of novel vaccines against SARS-CoV-2, concern among MS patients has now focused on the effect of DMTs on vaccine efficacy as well as general side effects. According to the National MS Society and the American Academy of Neurology, preventing infections via vaccination is essential to disease management among MS patients2,3. Evidence shows that infections may heighten the risk for MS exacerbations; therefore, vaccination may decrease the risk of relapses and as a result improve MS patients quality of life4. Further, there is a lack of prospective studies on the effect of DMTs on vaccine efficacy and side effects in Hispanic patients with MS. Objectives: Describe and report side effects and the response of Puerto Rican MS patients to the novel COVID-19 vaccines. Methods: A cross-sectional study was conducted in which data was obtained from an online survey developed by the San Juan MS Center research staff in collaboration with the Puerto Rico Multiple Sclerosis Foundation (PRMSF). Results: A total of 224 Puerto Rican MS patients with an average age of 43 years old participated in the study. The population consisted of 42 males and 182 females. Of these participants, 169 consulted their neurologist or primary care before receiving the vaccine. A total of 140 subjects received the Moderna vaccine, 79 the Pfizer vaccine, and 4 the Janssen vaccine. DMTs that this population were on at the time of vaccination included: teriflunomide (16), interferons (9), glatiramer acetate (12), S1P receptor modulators (50), B-cell depleting therapies (40), natalizumab (33), fumarates (40), and alemtuzumab (8). Only 16 patients were not on any DMT at the time of vaccination. The majority of participants (54.01%) experienced three or more symptoms after vaccination. The most common side effects reported by patients were pain at the injection site (170), tiredness (111) and headaches (99). Only 20 participants reported not experiencing any secondary side effects. Conclusions: The symptoms experienced by Puerto Rican MS patients after receiving the novel vaccines against SARS-CoV-2 did not differ from the symptoms experienced by the general population7. This study demonstrated that the majority of Puerto Rican MS patients were on DMTs at the time of vaccination and that they consulted their neurologist or primary care before their vaccination. This is an important step in decreasing vaccine hesitancy among MS patients through patient education for the implementation of an effective immunization strategy in line with the current guidelines.