Antigenic cartography using sera from sequence-confirmed SARS-CoV-2 variants of concern infections reveals antigenic divergence of Omicron.

Large-scale vaccination campaigns have prevented countless hospitalizations and deaths due to COVID-19. However, the emergence of SARS-CoV-2 variants that escape from immunity challenges the effectiveness of current vaccines. Given this continuing evolution, an important question is when and how to update SARS-CoV-2 vaccines to antigenically match circulating variants, similarly to seasonal influenza viruses where antigenic drift necessitates periodic vaccine updates. Here, we studied SARS-CoV-2 antigenic drift by assessing neutralizing activity against variants of concern (VOCs) in a set of sera from patients infected with viral sequence-confirmed VOCs. Infections with D614G or Alpha strains induced the broadest immunity, whereas individuals infected with other VOCs had more strain-specific responses. Omicron BA.1 and BA.2 were substantially resistant to neutralization by sera elicited by all other variants. Antigenic cartography revealed that Omicron BA.1 and BA.2 were antigenically most distinct from D614G, associated with immune escape, and possibly will require vaccine updates to ensure vaccine effectiveness.

Deterioration after corticosteroids in CIDP may be associated with pure focal demyelination pattern.

BACKGROUND: In the PREDICT study, a randomised controlled trial comparing dexamethasone with prednisolone in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), almost a quarter of patients deteriorated soon after starting treatment. The primary objective of this post-hoc analysis was to test the hypothesis that a focal demyelination pattern is associated with early deterioration after corticosteroid treatment and to explore whether various clinical characteristics are associated with deterioration after corticosteroid treatment. METHODS: Clinical outcome was categorised into early deterioration and non-early deterioration. A neurophysiologist blinded for treatment outcome scored electrophysiological data into following categories: pure focal versus non-focal distribution of demyelination and no/minor versus moderate/severe sensory involvement. Additionally, we compared electrophysiological and clinical baseline parameters, with emphasis on previously reported possible associations. RESULTS: Early deterioration was found in 7 out of 33 patients (21%). Ten patients had pure focal distribution of demyelination, of whom 5 had early deterioration; 23 patients had non-focal distribution, of whom 2 had early deterioration (p = 0.02). Higher mean median nerve sensory nerve conduction velocity (SNCV) was found in patients with early deterioration compared to patients with non-early deterioration (52.6 and respectively 40.8 m/s, p = 0.02). CONCLUSION: Pure focal distribution of demyelination and lesser sensory electrophysiological abnormalities may be associated with early deterioration in CIDP patients treated with corticosteroids.