Guillain-Barré syndrome and COVID-19 vaccines: focus on adenoviral vectors

Abstract

COVID-19 vaccination is a life-saving intervention. However, it does not come up without a risk of rare adverse events, which frequency varies between vaccines developed using different technological platforms. The increased risk of Guillain-Barré syndrome (GBS) has been reported for selected adenoviral vector vaccines but not for other vaccine types, including more widely used mRNA preparations. Therefore, it is unlikely that GBS results from the cross-reactivity of antibodies against the SARS-CoV-2 spike protein generated after the COVID-19 vaccination. This paper outlines two hypotheses according to which increased risk of GBS following adenoviral vaccination is due to (1) generation of anti-vector antibodies that may cross-react with proteins involved in biological processes related to myelin and axons, or (2) neuroinvasion of selected adenovirus vectors to the peripheral nervous system, infection of neurons and subsequent inflammation and neuropathies. The rationale behind these hypotheses is outlined, advocating further epidemiological and experimental research to verify them. This is particularly important given the ongoing interest in using adenoviruses in developing vaccines against various infectious diseases and cancer immunotherapeutics.

Caveats of chimpanzee ChAdOx1 adenovirus-vectored vaccines to boost anti-SARS-CoV-2 protective immunity in mice

“…In addition, the presence of previously induced anti-Ad antibodies could be linked to adverse effects such as Guillain-Barré syndrome, reported in individuals vaccinated with AZD1222 and Ad26.COV2. (Rzymski 2023 ).…”

BCG administration promotes the long-term protection afforded by a single-dose intranasal adenovirus-based SARS-CoV-2 vaccine

“… 67 Interestingly, an increase in GBS was not found when using COVID-19 vaccines based on HAdV5, unlike other vaccination platforms. 68 Despite this, considering the extreme infrequency of vaccine-related serious adverse events, most consider the increased risk of GBS miniscule in comparison to the protection against severe and lethal COVID-19 offered by vaccination. 69 Using a lower dose of viral-vectored vaccines may help to reduce the risk of adverse events even further and may point to an additional benefit of employing BCG as a means of immune enhancement whereby the combination with BCG may allow for a reduced dosing schedule or a reduction in the viral titer required to achieve effective vaccination.…”

Respiratory syncytial virus immunoprophylaxis: Novel opportunities and a call for equity

“…In the case of COVID-19 vaccines, these events included myo-and pericarditis following administration of mRNA vaccines and thrombotic thrombocytopenia and Guillain-Barré syndrome after vaccination with adenoviral vaccines. [74][75][76] Therefore, a pivotal need is to pursue comprehensive safety monitoring and risk management through pharmacovigilance in various age and racial groups. The cluster of specific side effects not observed during the clinical trials or their frequency exceeding the background levels requires further investigation to elucidate whether the association with vaccination time is only of a correlative nature.…”

“…Although the RSV vaccines and monoclonal antibodies were subjected to rigorous studies before approval, these studies, similarly to other clinical trials, were not designed to detect very rare adverse events that may occur after their administration. In the case of COVID‐19 vaccines, these events included myo‐ and pericarditis following administration of mRNA vaccines and thrombotic thrombocytopenia and Guillain‐Barré syndrome after vaccination with adenoviral vaccines 74‐76 . Therefore, a pivotal need is to pursue comprehensive safety monitoring and risk management through pharmacovigilance in various age and racial groups.…”