Current safety issues with quadrivalent meningococcal conjugate vaccines

Neurological and neuropsychological adverse effects of SARS-CoV-2 vaccines - where do we stand?

The devastating characteristic of COVID-19 pandemic calls for immediate and effective solutions to tackle it. Vaccines seem to be the only promising and effective way to fight against the novel coronavirus - even against new mutated variants. Because of the rapid development and distribution of numerous COVID-19 vaccines in different platforms, meticulous evaluation of vaccines' safety is more critical than ever - especially given the fact that most of the candidates have not completed the clinical phase. Therefore, to optimize the vaccines' safety and efficacy, it is highly important to carefully report and scientifically discuss the serious adverse effects following vaccination. In this respect, we discuss different neurological and neuropsychological adverse effects of COVID-19 vaccines including demyelinating diseases, Bell's palsy (BP), cerebrovascular complications, seizures, functional neurological disorders (FNDs), and some other rare adverse events, and hypothetical mechanisms which can lead to the reported side effects. Given the fact that the incidence of such events are rare and most of them are treatable, the current review aims to shed light on how much the relationship between COVID-19 vaccines and these complications can be reliable and provide an insight for future studies with much more meticulous methodologies to discuss the possible correlational or causal relationship between these complications and COVID-19 vaccines and elucidate whether or not the neurological side effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines can count as a considerable threat to public health.

Real-world evidence of quadrivalent meningococcal conjugate vaccine safety in the United States: a systematic review

Two quadrivalent meningococcal conjugate vaccines (MenACWY) that prevent invasive meningococcal disease caused by N. meningitidis serogroups A, C, Y, and W have been licensed in the U.S. in the past 10-15 years. We systematically reviewed published studies conducted in the U.S. to evaluate the real-world safety evidence of meningococcal conjugate vaccines. We performed a literature search in PubMed of publications from 01/01/2005 to 02/29/2020 and identified 18 studies meeting inclusion criteria. Populations included high-risk persons aged 2 months to 10 years, adolescents/adults aged ≥11 years, pregnant populations, and hematopoietic cell transplant recipients. We extracted information about study setting, study design, exposure, outcomes, comparison group, follow-up/look back period, study population, sample size, available demographic/indication information, results, key conclusion, and reference. These published studies found no new significant safety concerns related to MenACWY. Consideration for future research includes a post-licensure safety evaluation of a new MenACWY product approved in April 2020.