In vitro vaccine challenge of PBMCs from BNT162b2 anaphylaxis patients reveals HSP90α-NOD2-NLRP3 nexus

Anaphylaxis post-COVID-19 vaccinations in Singapore

INTRODUCTION

Anaphylaxis was the first serious adverse event (AE) of special interest surfaced in Singapore following coronavirus disease 2019 (COVID-19) vaccination. Individuals who developed physician-diagnosed severe allergic reactions to the mRNA vaccines would be medically ineligible for mRNA vaccines and offered non-mRNA alternatives. This paper describes anaphylaxis reports received by the Health Sciences Authority (HSA) and presents a review of individuals who received heterologous COVID-19 vaccination.

METHODS

Reports of anaphylaxis associated with the COVID-19 vaccines received till 31 July 2022 were reviewed and adjudicated using the Brighton Collaboration case definition criteria by an HSA-appointed expert panel. Additional review was conducted for cases with heterologous vaccination for any subsequent reactions until administration of third dose of COVID-19 vaccines.

RESULTS

Among 112 adjudicated anaphylaxis cases, majority occurred in females, adults and persons with allergy histories, which were consistent with global observations. Most cases (71%) occurred within 30 minutes of vaccination. The reporting incidence rates (IRs) of 0.67 and 0.55 per 100,000 administered doses for Comirnaty and Spikevax vaccines, respectively, were comparable with IRs reported overseas, whereas the IRs for non-mRNA vaccines (Sinovac-CoronaVac and Nuvaxovid) were much higher at 4.14 and 29.82 per 100,000 administered doses, respectively, likely due to selection bias. Review of the 20 cases following heterologous vaccination found varying reactions to subsequent vaccinations.

CONCLUSION

Anaphylaxis is a rare but serious AE in which outcomes can be mitigated with timely medical intervention. The case review helped to guide vaccination strategies and added to the cumulative knowledge of safety with heterologous vaccination.

Cutaneous adverse reactions associated with COVID-19 vaccines: Current evidence and potential immune mechanisms

As the number of vaccinated individuals has increased, there have been increasing reports of cutaneous hypersensitivity reactions. The main COVID-19 vaccines administered include messenger ribonucleic acid vaccines, non-replicating viral vector vaccines, inactivated whole-virus vaccines, and protein-based vaccines. These vaccines contain active components such as polyethylene glycol, polysorbate 80, aluminum, tromethamine, and disodium edetate dihydrate. Recent advances in understanding the coordination of inflammatory responses by specific subsets of lymphocytes have led to a new classification based on immune response patterns. We categorize these responses into four patterns: T helper (Th)1-, Th2-, Th17/22-, and Treg-polarized cutaneous inflammation after stimulation of COVID-19 vaccines. Although the association between COVID-19 vaccination and these cutaneous adverse reactions remains controversial, the occurrence of rare dermatoses and their short intervals suggest a possible relationship. Despite the potential adverse reactions, the administration of COVID-19 vaccines is crucial in the ongoing battle against severe acute respiratory syndrome coronavirus 2.

Self-DNA driven inflammation in COVID-19 and after mRNA-based vaccination: lessons for non-COVID-19 pathologies

The coronavirus disease 2019 (COVID-19) pandemic triggered an unprecedented concentration of economic and research efforts to generate knowledge at unequalled speed on deregulated interferon type I signalling and nuclear factor kappa light chain enhancer in B-cells (NF-κB)-driven interleukin (IL)-1β, IL-6, IL-18 secretion causing cytokine storms. The translation of the knowledge on how the resulting systemic inflammation can lead to life-threatening complications into novel treatments and vaccine technologies is underway. Nevertheless, previously existing knowledge on the role of cytoplasmatic or circulating self-DNA as a pro-inflammatory damage-associated molecular pattern (DAMP) was largely ignored. Pathologies reported 'de novo' for patients infected with Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 to be outcomes of self-DNA-driven inflammation in fact had been linked earlier to self-DNA in different contexts, e.g., the infection with Human Immunodeficiency Virus (HIV)-1, sterile inflammation, and autoimmune diseases. I highlight particularly how synergies with other DAMPs can render immunogenic properties to normally non-immunogenic extracellular self-DNA, and I discuss the shared features of the gp41 unit of the HIV-1 envelope protein and the SARS-CoV 2 Spike protein that enable HIV-1 and SARS-CoV-2 to interact with cell or nuclear membranes, trigger syncytia formation, inflict damage to their host's DNA, and trigger inflammation - likely for their own benefit. These similarities motivate speculations that similar mechanisms to those driven by gp41 can explain how inflammatory self-DNA contributes to some of most frequent adverse events after vaccination with the BNT162b2 mRNA (Pfizer/BioNTech) or the mRNA-1273 (Moderna) vaccine, i.e., myocarditis, herpes zoster, rheumatoid arthritis, autoimmune nephritis or hepatitis, new-onset systemic lupus erythematosus, and flare-ups of psoriasis or lupus. The hope is to motivate a wider application of the lessons learned from the experiences with COVID-19 and the new mRNA vaccines to combat future non-COVID-19 diseases.