RESUMO
To affirm the short-term safety of the BBIBP-CorV (Sinopharm) COVID-19 vaccine among people with multiple sclerosis (pwMS), 517 vaccinated and 174 unvaccinated pwMS were interviewed. 16.2% of the vaccinated pwMS reported at least one neurological symptom in their respective vaccine-related at-risk periods (ARP) - a period from the first dose until two weeks after the second dose of the vaccine. In a multivariable logistic regression model, the presence of comorbidities (P = 0.01), use of natalizumab (P = 0.03), and experiencing post-vaccination myalgia (P < 0.01) predicted the development of post-vaccination neurological symptoms. One MS relapse, one COVID-19 contraction, and one ulcerative colitis flare after the first dose, and four MS relapses after the second dose of the vaccine were the only reported serious adverse events during the ARPs. To show if the vaccine provoked MS relapses, we compared the relapse rate of vaccinated pwMS in the vaccine-related ARP with the annualized relapse rate of unvaccinated pwMS in the prior year-a measure of baseline MS relapsing activity in the respective time-using a multivariable Poisson regression model accounting for possible confounders, which failed to show any statistically significant increase (P = 0.78). Hence, subject to replication-as the vaccinated and unvaccinated pwMS differed in baseline characteristics-the BBIBP-CorV vaccine does not seem to affect short-term MS activity. Furthermore, as 83.33% of the unvaccinated pwMS reported fear of possible adverse events to be the reason of their vaccination hesitancy, provision of evidence-based consultations to pwMS is encouraged. Limitations of our study briefly included lack of data for self-controlled analysis of relapse rates, possible presence of recall bias, and lack of on-site validations regarding the clinical outcomes due to the remote nature.