Vaccination boosts protective responses and counters SARS-CoV-2-induced pathogenic memory B cells

Area of Science:

• Immunology
• Virology
• Vaccinology

Background:

• Understanding the interplay between SARS-CoV-2 infection and vaccination is crucial for effective public health strategies.
• Immune responses following infection and vaccination vary, impacting long-term immunity and potential sequelae like Long-COVID.

Approach:

• This study monitored SARS-CoV-2 Spike Receptor-Binding-Domain (RBD) specific immune responses in convalescent individuals for eight months post-infection and after vaccination.
• Key immune parameters analyzed included neutralizing antibodies, RBD-specific memory B cells, and dysfunctional double negative B memory cells.

Key Points:

• Neutralizing antibody levels specific to SARS-CoV-2 RBD generally decreased over time post-infection, while RBD-specific memory B cells remained persistent.
• Vaccination in convalescent individuals elicited more vigorous RBD-specific antibody and B cell responses compared to infection alone or vaccination in infection-naïve individuals.
• Frequencies of dysfunctional double negative B memory cells increased in convalescent subjects over time but were reversed by vaccination.

Conclusions:

• The findings reveal a novel aspect of immune dysfunction associated with mild to moderate COVID-19.
• SARS-CoV-2 vaccination is recommended for all individuals, irrespective of prior infection history.
• Vaccination may offer a mechanistic pathway to reduce the incidence or severity of Long-COVID symptoms.