COVID-19 and Vaccination in the Setting of Neurologic Disease: An Emerging Issue in Neurology

Adverse Events of COVID-19 Vaccines in the United States: Temporal and Spatial Analysis

BACKGROUND

The COVID-19 pandemic, caused by SARS-CoV-2, has had a profound impact worldwide, leading to widespread morbidity and mortality. Vaccination against COVID-19 is a critical tool in controlling the spread of the virus and reducing the severity of the disease. However, the rapid development and deployment of COVID-19 vaccines have raised concerns about potential adverse events following immunization (AEFIs). Understanding the temporal and spatial patterns of these AEFIs is crucial for an effective public health response and vaccine safety monitoring.

OBJECTIVE

This study aimed to analyze the temporal and spatial characteristics of AEFIs associated with COVID-19 vaccines in the United States reported to the Vaccine Adverse Event Reporting System (VAERS), thereby providing insights into the patterns and distributions of the AEFIs, the safety profile of COVID-19 vaccines, and potential risk factors associated with the AEFIs.

METHODS

We conducted a retrospective analysis of administration data from the Centers for Disease Control and Prevention (n=663,822,575) and reports from the surveillance system VAERS (n=900,522) between 2020 and 2022. To gain a broader understanding of postvaccination AEFIs reported, we categorized them into system organ classes (SOCs) according to the Medical Dictionary for Regulatory Activities. Additionally, we performed temporal analysis to examine the trends of AEFIs in all VAERS reports, those related to Pfizer-BioNTech and Moderna, and the top 10 AEFI trends in serious reports. We also compared the similarity of symptoms across various regions within the United States.

RESULTS

Our findings revealed that the most frequently reported symptoms following COVID-19 vaccination were headache (n=141,186, 15.68%), pyrexia (n=122,120, 13.56%), and fatigue (n=121,910, 13.54%). The most common symptom combination was chills and pyrexia (n=56,954, 6.32%). Initially, general disorders and administration site conditions (SOC 22) were the most prevalent class reported. Moderna exhibited a higher reporting rate of AEFIs compared to Pfizer-BioNTech. Over time, we observed a decreasing reporting rate of AEFIs associated with COVID-19 vaccines. In addition, the overall rates of AEFIs between the Pfizer-BioNTech and Moderna vaccines were comparable. In terms of spatial analysis, the middle and north regions of the United States displayed a higher reporting rate of AEFIs associated with COVID-19 vaccines, while the southeast and south-central regions showed notable similarity in symptoms reported.

CONCLUSIONS

This study provides valuable insights into the temporal and spatial patterns of AEFIs associated with COVID-19 vaccines in the United States. The findings underscore the critical need for increasing vaccination coverage, as well as ongoing surveillance and monitoring of AEFIs. Implementing targeted monitoring programs can facilitate the effective and efficient management of AEFIs, enhancing public confidence in future COVID-19 vaccine campaigns.

Safety of SARS-CoV-2 vaccine in patients with autoimmune neurological conditions: A systematic review and meta-analysis

Introduction

Risk of adverse effects and exacerbation in autoimmune neurological conditions (ANC)are frequently cited reasons for COVID-19 vaccine hesitancy. This study evaluates the ANC safety of COVID-19 vaccines in the real world.

Methods

Electronic databases were searched to identify studies reporting the use of the COVID-19 vaccine in ANC. We selected studies that provided data on adverse effects and worsening conditions related to ANC after vaccination. The pooled incidence rates for various adverse effects, stratified for the disease category, dosage, and type of vaccine, were estimated.

Results

Twenty-eight studies (31 vaccination cohorts) were included. The pooled incidence rate of general adverse events was 0.35 (95%CI, 0.27-0.43, I2 = 100 %). The pooled incidence rates of local injection reaction, fatigue, weakness, myalgia, fever, headache, and chills were 0.27 (0.18-0.36, I2 = 98 %), 0.16(0.11-0.21, I2 = 93 %), 0.15(0.00-0.31, I2 = 97 %), 0.13(0.08-0.19, I2 = 97 %), 0.11(0.07-0.15, I2 = 95 %), 0.11(0.07-0.16, I2 = 97 %), and 0.09 (0.03-0.16, I2 = 96 %), respectively. The pooled incidence rate of exacerbation adverse events was 0.05 (95%CI, 0.04-0.07, I2 = 84 %).

Conclusion

According to available evidence, the administration of COVID-19 vaccines in individuals with autoimmune neurological disorders seems well-tolerated, with few reports of adverse events. Furthermore, exacerbation of autoimmune neurological conditions following vaccination appears to be infrequent.

Intrinsic factors behind long-COVID: II. SARS-CoV-2, extracellular vesicles, and neurological disorders

With the decline in the number of new Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections, the World Health Organization announced the end of the SARS-CoV-2 pandemic. However, the repercussions of this viral pandemic may remain with us for a longer period of time, as it has remodeled the lives of humankind in many ways, including social and economic. Of course, its most important repercussions remain on the human health level. Long-coronavirus disease (COVID) or post-COVID is a state for which we do not have a concrete definition, a specific international classification of diseases Code, clear diagnostic tools, or well-known effective cures as of yet. In this second article from the Intrinsic Factors behind long-COVID Series, we try to link long-COVID symptoms with their causes, starting from the nervous system. Extracellular vesicles (ECVs) play very complex and ramified roles in the bodies of both healthy and not-healthy individuals. ECVs may facilitate the entry of many bioactive molecules and pathogens into the tissues and cells of the nervous system across the blood-brain barrier. Based on the size, quantity, and quality of their cargo, ECVs are directly proportional to the pathological condition and its severity through intertwined mechanisms that evoke inflammatory immune responses typically accompanied by pathological symptoms over variable time periods according to the type of these symptoms.

Development of Lewis-Sumner Syndrome or Multifocal Acquired Demyelinating Sensory and Motor Neuropathy (MADSAM) Following COVID-19 Infection

Multifocal acquired demyelinating sensory and motor neuropathy (MADSAM), also known as asymmetrical or multifocal chronic inflammatory demyelinating polyneuropathy (CIDP) or Lewis-Sumner syndrome, is a painless asymmetric demyelinating sensorimotor mononeuropathy multiplex and is an atypical and rare variant of CIDP. We report a case of a 48-year-old female who presented with complaints of shortness of breath, fatigue, difficulty walking and speaking, and primarily right unilateral symptoms involving multiple peripheral nerves, the right phrenic nerve, and the facial nerve following a coronavirus disease 2019 (COVID-19) infection. She was diagnosed with MADSAM after an extensive physical examination, electromyography (EMG), nerve conduction tests, and laboratory testing. She improved following the initiation of long-term treatment with intravenous immunoglobulin (IVIG). To the best of our knowledge, this is the second reported case of MADSAM following a COVID-19 infection. There have been reports of demyelinating diseases of the central and peripheral nervous systems related to COVID-19; however, it remains unclear whether COVID-19 is the causative agent or only a correlative.

Neurologic Complications of COVID-19

OBJECTIVE

This article describes the spectrum of neurologic complications occurring in acute or postacute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as the neurologic risks and benefits of vaccination against SARS-CoV-2.

LATEST DEVELOPMENTS

Early in the COVID-19 pandemic, reports of neurologic complications of COVID-19 began to surface. A variety of neurologic conditions have since been reported in association with COVID-19. Understanding of the underlying mechanism of COVID-19 neurologic involvement continues to evolve; however, the evidence seems to suggest that aberrant inflammatory responses may play a role. In addition to neurologic symptoms in acute COVID-19, neurologic post-COVID-19 conditions are increasingly recognized. The development of COVID-19 vaccines has been essential in preventing the spread of COVID-19. With increasing numbers of vaccine doses administered, various neurologic adverse events have been reported.

ESSENTIAL POINTS

Neurologists must be aware of the potential acute, postacute, and vaccine-associated neurologic complications associated with COVID-19 and be poised to serve as integral members of multidisciplinary care teams for patients with COVID-19-related conditions.

Evaluation of serum and cerebrospinal fluid biomarkers after vaccination against SARS-CoV-2

OBJECTIVE

Vaccines are a major achievement of science, and new vaccines against SARS-CoV-2 are protecting the entire population from a life-threatening infection. Although several neurological complications or worsening of pre-existing neurological conditions after vaccination have been observed, whether a biological plausibility exist between new vaccines against-SARS-CoV-2 and neurological consequences is unclear. The aim of this study is to evaluate whether vaccines against SARS-CoV-2 induce systemic or cerebrospinal fluid alterations in patients with neurological disorders.

METHODS

Patients who underwent lumbar puncture (LP) between February 2021 and October 2022 were enrolled. Serum C-reactive protein (CRP), neutrophil to lymphocyte ratio (NLR), cerebrospinal fluid total protein content (CSF-TPc), glucose CSF/serum ratio, number of CSF cells per cubic millimeter, and CSF neurofilament light chain (CSF-NfL) were compared between unvaccinated and vaccinated patients.

RESULTS

A total of 110 patients were included and fitted into three groups according firstly to vaccination status (vaccinated and unvaccinated) and then to time from last dose of vaccine to LP (within or after 3 months). TPc, CSF/SGlu ratio, number of cells per cubic millimeter, CSF-NfL, CRP, and NLR were not different between groups (all p > 0.05), and also, they did not differ neither according to age nor diagnosis. No relevant differences between groups were also noticed when the at-risk time window was set to 6 weeks.

INTERPRETATION

No signs of neuroinflammation, axonal loss and systemic inflammation were found in patients with neurological disorders after anti-SARS-CoV-2 vaccination compared with unvaccinated ones.

Ayurvedic management of neurological deficits post COVID-19 vaccination - A report of two cases

The world witnessed much research fund allocation on the COVID-19 outbreak's epidemiology, pathology, impact on lifestyles, social behaviours and treatment possibilities. The highly contagious nature of the disease compelled scientific communities and related organisations to hasten vaccine development and supplies. Well-timed international collaborations resulted in quicker development of varied forms of vaccines against COVID-19. Prospective observational studies and systematic reviews on vaccine trials reported their safety and efficacies. Nevertheless, post-marketing surveillance is quintessential to ascertain such safety and efficacy claims. There have been scattered reports lately of several adverse temporal events, such as haematological, immunological and neurological untoward occurrences following COVID-19 inoculation. There is a growing piece of evidence of the impact of COVID vaccination on patients with neurological-neuroimmunological disorders. Here two unrelated cases of neurological deficits post-COVID vaccination are reported. One was an incidence of Acute Disseminated Encephalomyelitis, while the other was an acute exacerbation of Multiple Sclerosis following vaccination. Ayurvedic treatments were effective in either of these conditions. Case series and case reports shall judiciously add information to vaccine safety data and acknowledge the necessity of clinician approval, based on detailed individualised assessments before mass vaccination.

Neurological Considerations with COVID-19 Vaccinations

The benefits of coronavirus disease 2019 (COVID-19) vaccination significantly outweigh its risks on a public health scale, and vaccination has been crucial in controlling the spread of SARS-CoV-2. Nonetheless, several reports of adverse events following vaccination have been published.To summarize reports to date and assess the extent and quality of evidence regarding possible serious adverse neurological events following COVID-19 vaccination, focusing on Food and Drug Administration (FDA)-approved vaccines in the United States (BNT162b2, mRNA-1273, and Ad26.COV2.S).A review of literature from five major electronic databases (PubMed, Medline, Embase, Cochrane Library, and Google Scholar) was conducted between December 1, 2020 and June 5, 2022. Articles included in the review were systematic reviews and meta-analysis, cohort studies, retrospective studies, case-control studies, case series, and reports. Editorials, letters, and animal studies were excluded, since these studies did not include quantitative data regarding adverse side effects of vaccination in human subjects.Of 149 total articles and 97 (65%) were case reports or case series. Three phase 3 trials initially conducted for BNT162b2, MRNA-1273, and Ad26.COV2.S were included in the analysis.The amount and quality of evidence for possible neurological adverse events in the context of FDA-approved COVID-19 vaccinations is overall low tier. The current body of evidence continues to suggest that COVID-19 vaccinations have a high neurological safety profile; however, the risks and benefits of vaccination must continue to be closely monitored.

Vertigo/dizziness following COVID-19 vaccination

PURPOSE

This study assessed the vertigo/dizziness in patients following COVID-19 vaccination.

PATIENTS AND METHODS

From July 2021 to June 2022, totaling 50 patients with dizzy spells following COVID-19 vaccination by AZ (AstraZeneca-Oxford University, AZD1222), BNT (Pfizer-BioNTech, BNT162b2) or Moderna (Moderna, mRNA-1273) vaccine were enrolled in this study. The interval from vaccination to the onset of vertigo/dizziness was compared with inter-episodic interval of vertigo/dizziness in the same patients, but without vaccination, during past one year (2020).

RESULTS

The incidences of severe systemic complication per 10⁶ shots were 0.86 for Moderna vaccine, 1.22 for AZ vaccine, and 1.23 for BNT vaccine. Conversely, rate of post-vaccination vertigo/dizziness was noted in the Moderna group (66 %), followed by the AZ group (20 %) and the BNT (14 %) group, meaning that type of COVID-19 vaccine may affect various organ systems. The median time to the onset of vertigo/dizziness following vaccination is 10d, which is consistent with the onset of IgG production, and significantly less than inter-episodic interval (84d) in the same patients without vaccination.

CONCLUSION

Post-vaccination vertigo/dizziness can manifest as exacerbation of previous neurotological disorder. The median time to the onset of vertigo/dizziness following COVID-19 vaccination is 10d. Since the outcome is fair after supportive treatment, the immunomodulatory effect of the vaccines does not undermine the necessity of the COVID-19 vaccination.

[Antibody production capacity after COVID-19 vaccination in immune-mediated neuromuscular diseases under immunotherapy]

The post-vaccination antibody response in patients with immune-mediated neuromuscular diseases under immuno-suppressive therapy has not been sufficiently verified. The Japanese Society of Neurology has stated that coronavirus disease 2019 (COVID-19) vaccination should be given priority in patients with immunotherapy-associated neuromuscular diseases; however, data on antibody production to a novel mRNA vaccine are scarce in these patients. In this study, we aimed to measure residual antibody titers after the second dose and produced antibodies after the third dose of SARS-CoV-2 mRNA vaccine in 25 patients with neuromuscular diseases under immuno-suppressive therapy (disease group). We compared the disease group antibody titers with those of 829 healthy employees in our hospital (control group). The disease group included 17 patients with myasthenia gravis, 4 with multiple sclerosis, 3 with inflammatory muscle disease, and 1 with chronic inflammatory demyelinating polyneuropathies. Seven cases of the disease group showed negative antibody levels (<15.0 s/co) before the third vaccination, and antibody titers in the positive cases ranged from 16.9 to 4,589.0 s/co. Three of the seven antibody-negative cases turned positive after the third vaccination, and all but one of the antibody-positive cases showed a booster effect, with antibody titers after the third dose ranging from 245.1 to 85,374.0 s/co (1.0 to 885.0 times higher than those before vaccination). Although the immune response in the disease group was modest compared to the control group, in which antibody titers after the third vaccination ranged from 67.8 to 150,000 s/co (0.9 to 5,402.1 times higher than those before vaccination), the result indicated that a constant immune response was achieved under immuno-suppressive therapy. Even in the control group, three participants tested negative for residual antibody before the third inoculation, and four of the antibody-positive participants (27.7-24,054.0 s/co) lacked a booster effect after the third vaccination.

Increasing Use of Telemedicine for Neurological Disorders During the COVID-19 Pandemic: A Mini-Review

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly contagious viral infection. In addition to its association with common pulmonary and gastrointestinal complications, COVID-19 is also associated with numerous neurological and neuropsychiatric conditions. This minireview aims to cover current literature addressing the application of telemedicine in neurological disorders and neuropsychiatric conditions, especially in response to the COVID-19 pandemic. This article revealed that quarantine, masking, and social distancing policies practiced during the COVID-19 pandemic involved restrictions and challenges to providing medical services, especially for patients with neurological disorders with or without COVID-19 infection. During the pandemic, both healthcare administrators and clinicians, including neurologists, have rapidly adapted or introduced telemedicine technologies for delivering specialty care. In some areas in the world, telemedicine has been successfully applied to reduce the impact imposed by COVID-19. Conclusively, this article supports the idea that telemedicine is an effective tool for providing specialized healthcare for patients with neurological conditions while adhering to social distancing or lockdown policies instituted during the COVID-19 pandemic. Government and medical/healthcare authorities, physicians and healthcare providers need to work together to expand the adoption of telemedicine applications, even after the COVID-19 crisis.

The relationship between myasthenia gravis and COVID-19: a systematic review

Introduction

Viral infection such as coronavirus disease 2019 (COVID-19) can exacerbate and aggravate neurological disorders due to autoimmune etiology like myasthenia gravis (MG). Experimental therapies used in COVID-19 are also factors that can cause the worsening of MG symptoms. This review aimed to assess and conclude the research-based study systematically to analyze the relationship of MG and COVID-19.

Method

This study was conducted in accordance to Cochrane handbook for systematic reviews and the guideline of preferred reporting items for systematic review and meta-analysis (PRISMA) and synthesis without meta-analysis (SWiM) in systematic reviews: reporting guideline. Inclusion criteria in this review were primary studies of every design, articles published in English around January 2000–October 2021, and the study used human as subject. A systematic literature finding was applied in 15 electronic scientific resources. The authors evaluated the study quality and risk of bias of each retrieved article.

Results

The authors found the study through electronic scientific resources that met inclusion and exclusion criteria. The authors evaluated 362 articles identified in literature searching, 22 articles met the criteria for this review and then underwent the evaluation of study quality and risk of bias.

Conclusion

COVID-19 infection can increase the risk of new-onset MG, myasthenic crisis, respiratory failure, and mortality rate due to cytokine storm in MG patients. The management of COVID-19 patients with MG is tailored to each person and based on national guidelines and local expert recommendations.

Adherence and Reactogenicity to Vaccines against SARS-COV-2 in 285 Patients with Neuropathy: A Multicentric Study

Background: The safety of the new vaccines against SARS-CoV-2 have already been shown, although data on patients with polyneuropathy are still lacking. The aim of this study is to evaluate the adherence to SARS-CoV-2 vaccination, as well as the reactogenicity to those vaccines in patients affected by neuropathy. Methods: A multicentric and web-based cross-sectional survey was conducted among patients affected by neuropathy from part of South Italy. Results: Out of 285 responders, n = 268 were included in the final analysis and n = 258 of them (96.3%) were fully vaccinated. Adherence to vaccination was higher in patients with hereditary neuropathies compared to others, while it was lower in patients with anti-MAG neuropathy (all p < 0.05). The overall prevalence of adverse events (AEs) was 61.2% and its occurrence was not associated with neuropathy type. Being female and of younger age were factors associated with higher risk of AEs, while having an inflammatory neuropathy and steroids assumption were associated with a lower risk (all p < 0.05). Younger age, having had an AE, and COVID-19 before vaccination were factors associated with symptoms worsening after vaccination (all p < 0.05). (4) Conclusions: Patients with neuropathy showed a high level of adherence to COVID-19 vaccination. Safety of vaccines in patients with neuropathies was comparable to the general population and it was more favorable in those with inflammatory neuropathy.

Bearing the Burden of Tick-Borne Encephalitis in Europe, 2012-2020: Rising Cases, Future Predictions and Climate Change

Background: Tick-borne encephalitis (TBE) is a central nervous system disease that is posing a growing public health challenge in Europe. Its disease burden, despite carrying a significant global impact, is still relatively unexplored. This study aims to outline a regression model of how the increasing cases will influence the burden of TBE in the upcoming years, using YLDs (years lived with disability) and DALYs (Disability-adjusted life years), and address climate change as a determinant. Methods: Information regarding the number of cases, YLDs and DALYs of TBE was collected from European countries using available surveillance data from 2012 to 2020. Number of TBE cases and burden projections were created until 2025, using a linear regression model. The total reported cases of TBE cases in this timeframe, age-group and gender distribution were inserted and modeled in ECDC BCoDE Toolkit, a software application that calculates the burden of communicable diseases, YLDs and DALYs of each year. A non-systematic bibliographic search was conducted exploring the impact of climate change on TBE. Results: Our findings showed a linear growth in number of TBE cases (74.3% increase), DALYs (71.3%), YLDs (71.75%) in European countries from 2012 to 2020. By 2025, these factors are likely to increase by 141% (95% CI: [108%,175%]), 134% (95% CI: [91%,177%]) and 134% (95% CI: [98%,172%]) compared to 2012, respectively (p<0.0001). Conclusions: The likelihood of morbidity and mortality increase of TBE, as well as climate-related changes in tick activity, highlight that prompt action is necessary by introducing preventive measures in European populations.

Exacerbation of Pre-existing Neurological Symptoms With COVID-19 in Patients With Chronic Neurological Diseases: An Updated Systematic Review

The neurotropism of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can potentially explain the worsening of symptoms in patients with a history of neurological conditions such as stroke, Parkinson's disease, Alzheimer's, and epilepsy. Several studies have reported that these pre-existing conditions may worsen with a higher frequency of flare-ups, thus resulting in a more significant risk of patient mortality. In this review, we sought to provide an overview of the relationship between pre-existing neurological disorders and COVID-19, focusing on whether the initial infection directly influenced the severity of symptoms. We systematically searched the electronic database PubMed (MEDLINE) and used specific keywords related to our aims from January 2020 to July 2022. All articles published on COVID-19 with keywords pertaining to pre-existing neurological diseases were retrieved and subsequently analyzed. After independent review, the data from 107 articles were selected and evaluated. After analyzing the data from selected articles reviewing the effect of COVID-19 on neurological conditions, we have documented the relationship between said pre-existing neurological diseases, showing an increased risk of hospitalization, admission length, worsening of symptoms, and even mortality in COVID-19 patients.

Vaccination of multiple sclerosis patients during the COVID-19 era: Novel insights into vaccine safety and immunogenicity

Multiple sclerosis (MS) is an incurable autoimmune disease known to cause widespread demyelinating lesions in the central nervous system (CNS) and a host of debilitating symptoms in patients. The development of MS is believed to be driven by the breakdown of the blood brain barrier, subsequent infiltration by CD4⁺ and CD8⁺ T cells, and widespread CNS inflammation and demyelination. Disease modifying therapies (DMTs) profoundly disrupt these processes and therefore compose an essential component of disease management. However, the effects of these therapeutic agents on vaccine safety and immunogenicity in individuals with MS are not yet fully understood. As such, the primary objective of this review article was to summarize the findings of recently conducted studies on vaccine safety and immunogenicity in MS patients treated with DMTs, particularly in the context of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Discussed in this review are vaccinations against influenza, yellow fever, human papillomavirus, measles, mumps, rubella, Streptococcus pneumoniae, hepatitis B, and COVID-19. This article additionally reviews our current understanding of COVID-19 severity and incidence in this patient population, the risks and benefits of vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and vaccination guidelines set forth by MS societies and organizations.

Postvaccinal GABA-B receptor antibody encephalitis after ChAdOx1 nCoV-19 vaccination

Several cases of autoimmune encephalitis have been reported after ChAdOx1 nCoV-19 (AZD1222) vaccination. We encountered a male patient who presented with generalized tonic-clonic seizures, cognitive decline, and gait disturbance that occurred suddenly after the second dose of the ChAdOx1 nCoV-19 vaccine. Clinical presentation and magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) test results were compatible with limbic encephalitis. Synaptic autoantibody tests confirmed serum and CSF GABA B receptor antibodies were present. The patient was treated with immunotherapy with intravenous immunoglobulin and rituximab. This GABA-B receptor antibody encephalitis case occurred presumably due to transient autoantibody production following vaccine administration.

Hot Topics on COVID-19 and Its Possible Association with Guillain-Barré Syndrome

As the COVID-19 pandemic progresses, reports of neurological manifestations are increasing. However, despite a high number of case reports and case series on COVID-19 and Guillain-Barré-Syndrome (GBS), a causal association is still highly debated, due to the lack of case-control studies. In this opinion paper, we focus on a few clinically relevant questions regarding the possible link between GBS and SARS-CoV-2 infection or vaccination based on our personal clinical experience and literature review.

Neurological consequences of COVID-19 and brain related pathogenic mechanisms: A new challenge for neuroscience

Due to the infection by the SARS-CoV-2 virus (COVID-19) there were also reported neurological symptoms, being the most frequent and best cited those that affect the cerebrovascular, sensorial, cognitive and motor functions, together with the neurological diffuse symptoms as for examples headache or dizziness. Besides, some of them behave high risk of mortality. Consequently, it is crucial to elucidate the mechanisms of action in brain of SARS-CoV-2 virus in order to create new therapeutic targets to fight against this new disease. Since now the mechanisms of arrival to the brain seems to be related with the following processes: blood brain barrier (BBB) disruption together with nervous or axonal transport of the virus by the trigeminal nerve, the vagus nerve, or the brain-gut-axis. Being two the mechanisms of brain affectation most cited: a direct affectation of the virus in the brain through neuroinvasion and an indirect mechanism of action due to the effects of the systemic infection. Both processes include the triggering of inflammation, hypoxia and the increased likelihood of secondary infections. This topic supposes a major novel challenge for neuroscience. Therefore, the aim of this review is to provide summarized information about the neurological symptomatology and the brain pathogenic mechanisms involved and reported in COVID-19.

Vaccination Against SARS-CoV-2 in Neuroinflammatory Disease: Early Safety/Tolerability Data

Background

Patients with autoimmune disease and on immunotherapy were largely excluded from seminal anti-SARS-CoV-2 vaccine trials. This has led to significant vaccine hesitancy in patients with neuroinflammatory diseases (NID); including, but not limited to: multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), neurosarcoidosis and myelin oligodendrocyte antibody-mediated disease (MOG-AD). Data is urgently needed to help guide clinical care in the NID population.

Methods

This was a cross-sectional observational study evaluating adults with a neurologist-confirmed diagnosis of a neuroinflammatory disease (NID) and a neurologically asymptomatic control population. Participants were recruited from multiple academic centers participating in the MS Resilience to COVID-19 Collaborative study. We analyzed participant responses from a vaccine-specific questionnaire collected between February and May 2021.

Results

1164 participants with NID and 595 controls completed the vaccine survey. Hesitancy rates were similar between NID and control groups (n = 134, 32.7% NID vs. n = 56, 30.6% control; p = 0.82). The most common reasons for hesitancy in NID participants were lack of testing in the autoimmune population and fear of demyelinating/neurologic events. Unvaccinated patients who had discussed vaccination with their doctor were less likely to be hesitant (n=184, 73.6% vs. n=83, 59.7%; p = 0.007). 634 NID patients and 332 controls had received at least one dose of a vaccine against SARS-CoV-2 at the time of survey completion. After adjusting for age, BMI, and comorbidities, there was no difference in self-reported side effects (SE) between groups with the first dose (n = 256, 42.2% NID vs. 141, 45.3% control; p = 0.20) or second dose (n = 246, 67.0% NID vs. n = 114, 64.8% control, p = 0.85) of the mRNA vaccines nor with the viral-vector vaccines (n = 6, 46% NID vs. n = 8, 66% control; p = 0.39). All reported SEs fell into the expected SE profile. There was no difference in report of new/recurrent neurologic symptoms (n = 110, 16.2% vaccinated vs. 71, 18.2% unvaccinated; p = 0.44) nor radiologic disease activity (n = 40, 5.9% vaccinated vs. n = 30, 7.6% unvaccinated) between vaccinated and unvaccinated NID participants.

Conclusions

We found no difference in patient-reported vaccine side effects and no evidence of NID worsening after vaccination. Large-scale real-world evidence is needed for further validation.